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1

Combined hydraulic and regenerative braking system  

DOEpatents

A combined hydraulic and regenerative braking system and method for an electric vehicle, with the braking system being responsive to the applied hydraulic pressure in a brake line to control the braking of the vehicle to be completely hydraulic up to a first level of brake line pressure, to be partially hydraulic at a constant braking force and partially regenerative at a linearly increasing braking force from the first level of applied brake line pressure to a higher second level of brake line pressure, to be partially hydraulic at a linearly increasing braking force and partially regenerative at a linearly decreasing braking force from the second level of applied line pressure to a third and higher level of applied line pressure, and to be completely hydraulic at a linearly increasing braking force from the third level to all higher applied levels of line pressure.

Venkataperumal, Rama R. (Troy, MI); Mericle, Gerald E. (Mount Clemens, MI)

1981-06-02

2

Piezoelectric-hydraulic pump based band brake actuation system for automotive transmission control  

NASA Astrophysics Data System (ADS)

The actuation system of friction elements (such as band brakes) is essential for high quality operations in modern automotive automatic transmissions (in short, ATs). The current band brake actuation system consists of several hydraulic components, including the oil pump, the regulating valve and the control valves. In general, it has been recognized that the current AT band brake actuation system has many limitations. For example, the oil pump and valve body are relatively heavy and complex. Also, the oil pumps induce inherently large drag torque, which affects fuel economy. This research is to overcome these problems of the current system by exploring the utilization of a hybrid type piezo-hydraulic pump device for AT band brake control. This new actuating system integrates a piezo-hydraulic pump to the input of the band brake. Compared with the current systems, this new actuator features much simpler structure, smaller size, and lower weight. This paper describes the development, design and fabrication of the new stand-alone prototype actuator for AT band brake control. An analytical model is developed and validated using experimental data. Performance tests on the hardware and system simulations utilizing the validated model are performed to characterize the new prototype actuator. It is predicted that with increasing of accumulator pressure and driving frequency, the proposed prototype actuating system will satisfy the band brake requirement for AT shift control.

Kim, Gi-Woo; Wang, K. W.

2007-04-01

3

49 CFR 570.55 - Hydraulic brake system.  

Code of Federal Regulations, 2010 CFR

...Measure the distance (i) from the free pedal position to the floor board or other object that restricts brake pedal travel. Depress the brake pedal, and with the force applied measure the distance (ii) from the depressed pedal position to the floor...

2010-10-01

4

49 CFR 570.55 - Hydraulic brake system.  

Code of Federal Regulations, 2011 CFR

...Measure the distance (i) from the free pedal position to the floor board or other object that restricts brake pedal travel. Depress the brake pedal, and with the force applied measure the distance (ii) from the depressed pedal position to the floor...

2011-10-01

5

Fault diagnosis of automobile hydraulic brake system using statistical features and support vector machines  

NASA Astrophysics Data System (ADS)

Hydraulic brakes in automobiles are important components for the safety of passengers; therefore, the brakes are a good subject for condition monitoring. The condition of the brake components can be monitored by using the vibration characteristics. On-line condition monitoring by using machine learning approach is proposed in this paper as a possible solution to such problems. The vibration signals for both good as well as faulty conditions of brakes were acquired from a hydraulic brake test setup with the help of a piezoelectric transducer and a data acquisition system. Descriptive statistical features were extracted from the acquired vibration signals and the feature selection was carried out using the C4.5 decision tree algorithm. There is no specific method to find the right number of features required for classification for a given problem. Hence an extensive study is needed to find the optimum number of features. The effect of the number of features was also studied, by using the decision tree as well as Support Vector Machines (SVM). The selected features were classified using the C-SVM and Nu-SVM with different kernel functions. The results are discussed and the conclusion of the study is presented.

Jegadeeshwaran, R.; Sugumaran, V.

2015-02-01

6

Automotive Brake Systems.  

ERIC Educational Resources Information Center

This correspondence course, orginally developed for the Marine Corps, is designed to provide mechanics with an understanding of the basic operations of automotive brake systems on military vehicles. The course contains four study units covering hydraulic brakes, air brakes, power brakes, and auxiliary brake systems. A troubleshooting guide for…

Marine Corps Inst., Washington, DC.

7

Hydraulic Drivetrain and Regenerative Braking Team 13: Andrew Brown, Karan Desai, Andrew McGrath, Hurst Nuckols, Grant Wilson Adviser: Dr. Andrew Jackson  

E-print Network

Hydraulic Drivetrain and Regenerative Braking Team 13: Andrew Brown, Karan Desai, Andrew Mc Pressure Reservior Filter Variable Vane Pump Motor/Pump Hydraulic Accumulators Solenoid Valve Relief Valve Suction Line Since their development in 2006, hydraulic drivetrain systems have gained considerable

Carpick, Robert W.

8

76 FR 7623 - Parts and Accessories Necessary for Safe Operation; Brakes; Application for Exemption From...  

Federal Register 2010, 2011, 2012, 2013

...self-contained, permanently closed hydraulic brake system'' [Emphasis added...FMCSRs to allow the use of automatic hydraulic inertia brake systems (surge brakes...self-contained, permanently closed hydraulic brake system for trailers that...

2011-02-10

9

49 CFR 393.47 - Brake actuators, slack adjusters, linings/pads and drums/rotors.  

...for hydraulic disc, drum and electric brakes. (2) Non-steering...air braked commercial motor vehicle shall not be operated with...disc brakes. Hydraulic or electric braked commercial motor vehicles shall not be operated...

2014-10-01

10

Diesel Technology: Brakes. Teacher Edition [and] Student Edition.  

ERIC Educational Resources Information Center

This document contains teacher and student materials for a course on brakes in the diesel technology curriculum. The course consists of 12 units organized in three sections. The three units of the introductory section cover: (1) brakes; (2) wheel bearings and seals; and (3) antilock brake systems. The second section, Hydraulic Brakes, contains the…

Hilley, Robert; Scarberry, Terry; Kellum, Mary

11

Hydraulics.  

ERIC Educational Resources Information Center

This curriculum guide contains a course in hydraulics to train entry-level workers for automotive mechanics and other fields that utilize hydraulics. The module contains 14 instructional units that cover the following topics: (1) introduction to hydraulics; (2) fundamentals of hydraulics; (3) reservoirs; (4) lines, fittings, and couplers; (5)…

Decker, Robert L.; Kirby, Klane

12

Hydraulics.  

ERIC Educational Resources Information Center

These instructional materials provide an orientation to hydraulics for use at the postsecondary level. The first of 12 sections presents an introduction to hydraulics, including discussion of principles of liquids, definitions, liquid flow, the two types of hydraulic fluids, pressure gauges, and strainers and filters. The second section identifies…

Engelbrecht, Nancy; And Others

13

Optimal robust control of a contactless brake system using an eddy current  

Microsoft Academic Search

As vehicle speed increases, a more powerful brake system is required to ensure vehicle safety and its reliability. A contactless eddy current brake (ECB) is developed to take the superior advantages of fast anti-lock braking to the conventional hydraulic brake systems. Braking torque analysis is performed by using an approximate theoretical model and the model is modified through experiments to

Kapjin Lee

1999-01-01

14

Gravity brake  

DOEpatents

A mechanical gravity brake that prevents hoisted loads within a shaft from free-falling when a loss of hoisting force occurs. A loss of hoist lifting force may occur in a number of situations, for example if a hoist cable were to break, the brakes were to fail on a winch, or the hoist mechanism itself were to fail. Under normal hoisting conditions, the gravity brake of the invention is subject to an upward lifting force from the hoist and a downward pulling force from a suspended load. If the lifting force should suddenly cease, the loss of differential forces on the gravity brake in free-fall is translated to extend a set of brakes against the walls of the shaft to stop the free fall descent of the gravity brake and attached load.

Lujan, Richard E. (Santa Fe, NM)

2001-01-01

15

78 FR 21189 - Agency Requests for Approval of a New Information Collection: Motor Vehicle Brake Fluids  

Federal Register 2010, 2011, 2012, 2013

...brake fluids as well as packagers of hydraulic system mineral oils. The information...requirements for motor vehicle brake fluids and hydraulic system mineral oils. Section 5.2...brake fluids as well as packagers of hydraulic system mineral oils. The...

2013-04-09

16

Hydraulics.  

ERIC Educational Resources Information Center

Designed for use in courses where students are expected to become proficient in the area of hydraulics, including diesel engine mechanic programs, this curriculum guide is comprised of fourteen units of instruction. Unit titles include (1) Introduction, (2) Fundamentals of Hydraulics, (3) Reservoirs, (4) Lines, Fittings, and Couplers, (5) Seals,…

Decker, Robert L.

17

Braking system  

DOEpatents

A balanced braking system comprising a plurality of braking assemblies located about a member to be braked. Each of the braking assemblies consists of a spring biased piston of a first material fitted into a body of a different material which has a greater contraction upon cooling than the piston material. The piston is provided with a recessed head portion over which is positioned a diaphragm and forming a space therebetween to which is connected a pressurized fluid supply. The diaphragm is controlled by the fluid in the space to contact or withdraw from the member to be braked. A cooling means causes the body within which the piston is fitted to contract more than the piston, producing a tight shrink fit therebetween. The braking system is particularly applicable for selectively braking an arbor of an electron microscope which immobilizes, for example, a vertically adjustable low temperature specimen holder during observation. The system provides balanced braking forces which can be easily removed and re-established with minimal disturbance to arbor location.

Norgren, D.U.

1982-09-23

18

Electric vehicle regenerative antiskid braking and traction control system  

DOEpatents

An antiskid braking and traction control system for an electric or hybrid vehicle having a regenerative braking system operatively connected to an electric traction motor, and a separate hydraulic braking system includes one or more sensors for monitoring present vehicle parameters and a processor, responsive to the sensors, for calculating vehicle parameters defining the vehicle behavior not directly measurable by the sensors and determining if regenerative antiskid braking control, requiring hydrualic braking control, or requiring traction control are required. The processor then employs a control strategy based on the determined vehicle state and provides command signals to a motor controller to control the operation of the electric traction motor and to a brake controller to control fluid pressure applied at each vehicle wheel to provide the appropriate regenerative antiskid braking control, hydraulic braking control, and traction control.

Cikanek, Susan R. (Wixom, MI)

1995-01-01

19

Hydraulics  

NSDL National Science Digital Library

These interactive learning objects, created by instructors from Fox Valley Technical College and other colleges in the Wisconsin Technical College program, focus on concepts that cover a broad-based electromechanical program. Here visitors will find learning objects in Hydraulics with over 25 lessons in Actuators, Relief Valves, Basic Concepts, and Directional Control Valves.

20

Fuzzy logic electric vehicle regenerative antiskid braking and traction control system  

DOEpatents

An regenerative antiskid braking and traction control system using fuzzy logic for an electric or hybrid vehicle having a regenerative braking system operatively connected to an electric traction motor, and a separate hydraulic braking system includes sensors for monitoring present vehicle parameters and a processor, responsive to the sensors, for calculating vehicle parameters defining the vehicle behavior not directly measurable by the sensor and determining if regenerative antiskid braking control, requiring hydraulic braking control, and requiring traction control are required. The processor then employs fuzzy logic based on the determined vehicle state and provides command signals to a motor controller to control operation of the electric traction motor and to the brake controller to control fluid pressure applied at each vehicle wheel to provide the appropriate regenerative braking control, hydraulic braking control, and traction control.

Cikanek, Susan R. (Wixom, MI)

1994-01-01

21

49 CFR 393.41 - Parking brake system.  

Code of Federal Regulations, 2011 CFR

...found on a public road (free of ice and snow). Hydraulic-braked vehicles which...found on a public road (free of ice and snow). An agricultural commodity trailer...found on a public road (free of ice and snow). (2) The parking brake...

2011-10-01

22

49 CFR 393.41 - Parking brake system.  

Code of Federal Regulations, 2013 CFR

...found on a public road (free of ice and snow). Hydraulic-braked vehicles which...found on a public road (free of ice and snow). An agricultural commodity trailer...found on a public road (free of ice and snow). (2) The parking brake...

2013-10-01

23

49 CFR 393.41 - Parking brake system.  

Code of Federal Regulations, 2012 CFR

...found on a public road (free of ice and snow). Hydraulic-braked vehicles which...found on a public road (free of ice and snow). An agricultural commodity trailer...found on a public road (free of ice and snow). (2) The parking brake...

2012-10-01

24

A unique concept for automatically controlling the braking action of wheeled vehicles during minimum distance stops  

NASA Technical Reports Server (NTRS)

Test results of a unique automatic brake control system are outlined and a comparison is made of its mode of operation to that of an existing skid control system. The purpose of the test system is to provide automatic control of braking action such that hydraulic brake pressure is maintained at a near constant, optimum value during minimum distance stops.

Barthlome, D. E.

1975-01-01

25

14 CFR 25.735 - Brakes and braking systems.  

Code of Federal Regulations, 2013 CFR

...design landing stop brake kinetic energy absorption requirement of each wheel, brake...wear range of the brake. The energy absorption rate derived from the airplane manufacturer's...accelerate-stop brake kinetic energy absorption requirement of each wheel,...

2013-01-01

26

14 CFR 25.735 - Brakes and braking systems.  

Code of Federal Regulations, 2012 CFR

...design landing stop brake kinetic energy absorption requirement of each wheel, brake...wear range of the brake. The energy absorption rate derived from the airplane manufacturer's...accelerate-stop brake kinetic energy absorption requirement of each wheel,...

2012-01-01

27

14 CFR 25.735 - Brakes and braking systems.  

...design landing stop brake kinetic energy absorption requirement of each wheel, brake...wear range of the brake. The energy absorption rate derived from the airplane manufacturer's...accelerate-stop brake kinetic energy absorption requirement of each wheel,...

2014-01-01

28

Research on brake disk modal characteristic of disk brake  

Microsoft Academic Search

The brake disk modal characteristic of disk brake is an important factor for braking stability of the whole system. In order to reduce the judder and noise in braking process, the ANSYS software was applied to conduct the modal simulation analysis of brake disk, and a multi-purpose experimental bench was built for modal test of brake disk. The results including

Liya Yao

2011-01-01

29

TGV disc brake squeal  

NASA Astrophysics Data System (ADS)

The discomfort generated by the noise emission of braking systems in trains has aroused recently many studies on the mechanical modelling of brake noise in France. A theoretical and numerical discussion on the phenomenon of brake squeal is given in this paper in relation with some experimental data. This study is based upon a flutter instability analysis giving unstable modes of the brake system under the contact and Coulomb friction.

Lorang, X.; Foy-Margiocchi, F.; Nguyen, Q. S.; Gautier, P. E.

2006-06-01

30

TGV disc brake squeal  

Microsoft Academic Search

The discomfort generated by the noise emission of braking systems in trains has aroused recently many studies on the mechanical modelling of brake noise in France. A theoretical and numerical discussion on the phenomenon of brake squeal is given in this paper in relation with some experimental data. This study is based upon a flutter instability analysis giving unstable modes

X. Lorang; F. Foy-Margiocchi; Q. S. Nguyen; P. E. Gautier

2006-01-01

31

Roller Locking Brake  

NASA Technical Reports Server (NTRS)

Roller locking brake is normally braking rotary mechanism allowing free rotation when electromagnet in mechanism energized. Well suited to robots and other machinery which automatic braking upon removal of electrical power required. More compact and reliable. Requires little electrical power to maintain free rotation and exhibits minimal buildup of heat.

Vranish, John M.

1993-01-01

32

Automotive Drum Brakes  

NSDL National Science Digital Library

Do you know when the first car was built? Do you know who built the first automobile? Would you guess, Henry Ford? Try again. Do you know by what means they used to stop that car? We know the brakes on the vehicles we drive today are quite different from those back in the 1800s. While knowing the history of the automobile is interesting, knowing how they work is also interesting. The automotive brake or to be more specific, the drum brake is what this instruction is designed to review. In this instruction, we will begin by briefly looking at the history of automobile brakes and then learn how drum brakes work. While disk brakes can be easier to understand, are becoming more and more popular, especially on the rear tires, drum brakes, to some can be a challenge. The purpose of this lesson is to provide you with resources and encourage you to search more additional resources that will help you gain a mental moving picture of how the drum brake works. OBJECTIVES: In this instructional module, you will: Know a brief history of automobile brakes. Have a minimum of 8 web resources that provide instructions of drum brakes. Develop a mental moving picture of how drum brakes work. MATERIALS: To complete this learning activity, each student will need: Access to a computer with internet connection capabilities. A strong desire ...

Mr. Hjorten

2006-02-03

33

A New Dynamometer Brake  

NASA Technical Reports Server (NTRS)

The mechanism here described belongs to the class of dynamometer brake in which the motive power is transformed into heat in the brake itself. This mechanism was invented by the writer for the purpose of measuring forces in which the two factors, torque and speed, vary within broad limits, the mechanism itself being of simple construction and of still simpler operation.

Segre, Marco

1921-01-01

34

Brake for rollable platform  

NASA Technical Reports Server (NTRS)

Frame-mounted brake is independent of wheels and consists of simple lever-actuated foot. Brake makes good contact with surface even though foot pad is at higher or lower level than wheels, this is particularly important when a rollable platform is used on irregular surface.

Morris, A. L.

1974-01-01

35

WIND BRAKING OF MAGNETARS  

SciTech Connect

We explore the wind braking of magnetars considering recent observations challenging the traditional magnetar model. There is evidence for strong multipole magnetic fields in active magnetars, but the dipole field inferred from spin-down measurements may be strongly biased by particle wind. Recent observations challenging the traditional model of magnetars may be explained naturally by the wind braking scenario: (1) the supernova energies of magnetars are of normal value; (2) the non-detection in Fermi observations of magnetars; (3) the problem posed by low magnetic field soft gamma-ray repeaters; (4) the relation between magnetars and high magnetic field pulsars; and (5) a decreasing period derivative during magnetar outbursts. Transient magnetars with L{sub x}<- E-dot{sub rot} may still be magnetic dipole braking. This may explain why low luminosity magnetars are more likely to have radio emissions. A strong reduction of the dipole magnetic field is possible only when the particle wind is very collimated at the star surface. A small reduction of the dipole magnetic field may result from detailed considerations of magnetar wind luminosity. In the wind braking scenario, magnetars are neutron stars with a strong multipole field. For some sources, a strong dipole field may no longer be needed. A magnetism-powered pulsar wind nebula will be one of the consequences of wind braking. For a magnetism-powered pulsar wind nebula, we should see a correlation between the nebula luminosity and the magnetar luminosity. Under the wind braking scenario, a braking index smaller than three is expected. Future braking index measurement of a magnetar may tell us whether magnetars are wind braking or magnetic dipole braking.

Tong, H. [Xinjiang Astronomical Observatory, Chinese Academy of Sciences, Urumqi, Xinjiang 830011 (China); Xu, R. X.; Qiao, G. J. [KIAA and School of Physics, Peking University, Beijing 100871 (China); Song, L. M., E-mail: tonghao@xao.ac.cn [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China)

2013-05-10

36

Improved Electromagnetic Brake  

NASA Technical Reports Server (NTRS)

A proposed design for an electromagnetic brake would increase the reliability while reducing the number of parts and the weight, relative to a prior commercially available electromagnetic brake. The reductions of weight and the number of parts could also lead to a reduction of cost. A description of the commercial brake is prerequisite to a description of the proposed electromagnetic brake. The commercial brake (see upper part of figure) includes (1) a permanent magnet and an electromagnet coil on a stator and (2) a rotor that includes a steel contact plate mounted, with tension spring loading, on an aluminum hub. The stator is mounted securely on a stationary object, which would ordinarily be the housing of a gear drive or a motor. The rotor is mounted on the shaft of the gear drive or motor. The commercial brake nominally operates in a fail-safe (in the sense of normally braking) mode: In the absence of current in the electromagnet coil, the permanent magnet pulls the contact plate, against the spring tension, into contact with the stator. To release the brake, one excites the electromagnet with a current of the magnitude and polarity chosen to cancel the magnetic flux of the permanent magnet, thereby enabling the spring tension to pull the contact plate out of contact with the stator. The fail-safe operation of the commercial brake depends on careful mounting of the rotor in relation to the stator. The rotor/stator gap must be set with a tolerance between 10 and 15 mils (between about 0.25 and about 0.38 mm). If the gap or the contact pad is thicker than the maximum allowable value, then the permanent magnetic field will not be strong enough to pull the steel plate across the gap. (For this reason, any contact pad between the contact plate and the stator must also be correspondingly thin.) If the gap exceeds the maximum allowable value because of shaft end play, it becomes impossible to set the brake by turning off the electromagnet current. Although it may still be possible to set the brake by applying an electromagnet current to aid the permanent magnetic field instead of canceling it, this action can mask an out-of-tolerance condition in the brake and it does not restore the fail-safe function of setting the brake when current is lost.

Martin, Toby B.

2004-01-01

37

29 CFR 1919.22 - Requirements governing braking devices and power sources.  

Code of Federal Regulations, 2011 CFR

...All types of winches and cranes shall be provided with...electrohydraulic winches fitted with electromagnetic or hydraulic brakes at the winch, or electric cranes shall be equipped so...of electric winches and cranes during the tests...

2011-07-01

38

29 CFR 1919.22 - Requirements governing braking devices and power sources.  

...All types of winches and cranes shall be provided with...electrohydraulic winches fitted with electromagnetic or hydraulic brakes at the winch, or electric cranes shall be equipped so...of electric winches and cranes during the tests...

2014-07-01

39

29 CFR 1919.22 - Requirements governing braking devices and power sources.  

Code of Federal Regulations, 2013 CFR

...All types of winches and cranes shall be provided with...electrohydraulic winches fitted with electromagnetic or hydraulic brakes at the winch, or electric cranes shall be equipped so...of electric winches and cranes during the tests...

2013-07-01

40

29 CFR 1919.22 - Requirements governing braking devices and power sources.  

Code of Federal Regulations, 2012 CFR

...All types of winches and cranes shall be provided with...electrohydraulic winches fitted with electromagnetic or hydraulic brakes at the winch, or electric cranes shall be equipped so...of electric winches and cranes during the tests...

2012-07-01

41

Vehicle brake testing system  

DOEpatents

This invention relates to a force measuring system capable of measuring forces associated with vehicle braking and of evaluating braking performance. The disclosure concerns an invention which comprises a first row of linearly aligned plates, a force bearing surface extending beneath and beside the plates, vertically oriented links and horizontally oriented links connecting each plate to a force bearing surface, a force measuring device in each link, a transducer coupled to each force measuring device, and a computing device coupled to receive an output signal from the transducer indicative of measured force in each force measuring device. The present invention may be used for testing vehicle brake systems.

Stevens, Samuel S. (Harriman, TN); Hodgson, Jeffrey W. (Lenoir City, TN)

2002-11-19

42

Commercial Motor Vehicle Brake Assessment Tools  

E-print Network

ability #12;Performance-Based Brake Tester · Assessment of brake efficiency ­ BE = ­ Equivalent performance Total Braking Force Total Vehicle Weight Total Braking Force Total Vehicle Weight #12;Related

43

14 CFR 25.735 - Brakes and braking systems.  

Code of Federal Regulations, 2010 CFR

...AIRPLANES Design and Construction Landing Gear § 25.735 Brakes and braking...that obtained in determining the landing distance as prescribed in § 25...energy capacity —(1) Design landing stop. The design landing...

2010-01-01

44

14 CFR 25.735 - Brakes and braking systems.  

Code of Federal Regulations, 2011 CFR

...AIRPLANES Design and Construction Landing Gear § 25.735 Brakes and braking...that obtained in determining the landing distance as prescribed in § 25...energy capacity —(1) Design landing stop. The design landing...

2011-01-01

45

Chaos in brake squeal noise  

Microsoft Academic Search

Brake squeal has become an increasing concern to the automotive industry because of warranty costs and the requirement for continued interior vehicle noise reduction. Most research has been directed to either analytical and experimental studies of brake squeal mechanisms or the prediction of brake squeal propensity using finite element methods. By comparison, there is a lack of systematic analysis of

S. Oberst; J. C. S. Lai

2011-01-01

46

Braking and bouncing  

E-print Network

I discuss the case for an efficient orbital braking mechanism in CVs, and the effect of nova outbursts on the observed range of mass transfer rates. I review the continuing problem that models have in interpreting the short-period cut-off of the CV period distribution.

U. Kolb

2001-10-10

47

Comparative analysis into the tractor-trailer braking dynamics: tractor with single axle brakes, tractor with all wheel brakes  

NASA Astrophysics Data System (ADS)

The paper elaborates a mathematical model in order to conduct a study into the dynamics of tractor-trailer systems during braking. The braking dynamics is analyzed by considering two versions for the braking system: 1) braking applied on the rear axle and 2) braking applied on all four wheels. In both versions the trailer is braked on all wheels. The mathematical model enables us to determine and graphically illustrate the evolution of the following parameters: braking deceleration, braking speed and the distance traveled by the tractor during braking. The mathematical model elaborated is applied on a tractor-trailer system completing transportation works.

Nastasoiu, Mircea; Ispas, Nicolae

2014-06-01

48

49 CFR 236.508 - Interference with application of brakes by means of brake valve.  

Code of Federal Regulations, 2012 CFR

...Transportation 4 2012-10-01 2012-10-01 false Interference with application of brakes by means of brake valve. 236...Control and Cab Signal Systems Standards § 236.508 Interference with application of brakes by means of brake...

2012-10-01

49

49 CFR 236.508 - Interference with application of brakes by means of brake valve.  

Code of Federal Regulations, 2010 CFR

...Transportation 4 2010-10-01 2010-10-01 false Interference with application of brakes by means of brake valve. 236...Control and Cab Signal Systems Standards § 236.508 Interference with application of brakes by means of brake...

2010-10-01

50

Thermal cracking in disc brakes  

Microsoft Academic Search

Disc brakes are exposed to large thermal stresses during routine braking and extraordinary thermal stresses during hard braking. High-g decelerations typical of passenger vehicles are known to generate temperatures as high as 900°C in a fraction of a second. These large temperature excursions have two possible outcomes: thermal shock that generates surface cracks; and\\/or large amounts of plastic deformation in

Thomas J. Mackin; Steven C. Noe; K. J. Ball; B. C. Bedell; D. P. Bim-Merle; M. C. Bingaman; D. M. Bomleny; G. J. Chemlir; D. B. Clayton; H. A. Evans; R. Gau; J. L. Hart; J. S. Karney; B. P. Kiple; R. C. Kaluga; P. Kung; A. K. Law; D. Lim; R. C. Merema; B. M. Miller; T. R. Miller; T. J. Nielson; T. M. O'Shea; M. T. Olson; H. A. Padilla; B. W. Penner; C. Penny; R. P. Peterson; V. C. Polidoro; A. Raghu; B. R. Resor; B. J. Robinson; D. Schambach; B. D. Snyder; E. Tom; R. R. Tschantz; B. M. Walker; K. E. Wasielewski; T. R. Webb; S. A. Wise; R. S. Yang; R. S. Zimmerman

2002-01-01

51

14 CFR 23.735 - Brakes.  

Code of Federal Regulations, 2011 CFR

...AIRPLANES Design and Construction Landing Gear § 23.735 Brakes. (a) Brakes must be provided. The landing brake kinetic energy capacity...sequence of events expected during landing at the design landing...

2011-01-01

52

14 CFR 23.735 - Brakes.  

Code of Federal Regulations, 2010 CFR

...AIRPLANES Design and Construction Landing Gear § 23.735 Brakes. (a) Brakes must be provided. The landing brake kinetic energy capacity...sequence of events expected during landing at the design landing...

2010-01-01

53

Chaos in brake squeal noise  

NASA Astrophysics Data System (ADS)

Brake squeal has become an increasing concern to the automotive industry because of warranty costs and the requirement for continued interior vehicle noise reduction. Most research has been directed to either analytical and experimental studies of brake squeal mechanisms or the prediction of brake squeal propensity using finite element methods. By comparison, there is a lack of systematic analysis of brake squeal data obtained from a noise dynamometer. It is well known that brake squeal is a nonlinear transient phenomenon and a number of studies using analytical and experimental models of brake systems (e.g., pin-on-disc) indicate that it could be treated as a chaotic phenomenon. Data obtained from a full brake system on a noise dynamometer were examined with nonlinear analysis techniques. The application of recurrence plots reveals chaotic structures even in noisy data from the squealing events. By separating the time series into different regimes, lower dimensional attractors are isolated and quantified by dynamic invariants such as correlation dimension estimates or Lyapunov exponents. Further analysis of the recurrence plot of squealing events by means of recurrence quantification analysis measures reveals different regimes of laminar and random behaviour, periodicity and chaos-forming recurrent transitions. These results help to classify brake squeal mechanisms and to enhance understanding of friction-related noise phenomena.

Oberst, S.; Lai, J. C. S.

2011-02-01

54

49 CFR 238.431 - Brake system.  

Code of Federal Regulations, 2010 CFR

...unit. (d) The brake system shall be designed to prevent...apply to blended braking systems: (1) Loss of power or failure of the dynamic brake does not result in...electric portion of the brake system shall be displayed for...

2010-10-01

55

49 CFR 238.231 - Brake system.  

Code of Federal Regulations, 2010 CFR

...known that the air brake system is properly charged...blending of friction and dynamic brake to obtain the...automatic; (2) Loss of power or failure of the dynamic brake does not result...new designs of braking systems, the design...

2010-10-01

56

49 CFR 238.431 - Brake system.  

Code of Federal Regulations, 2013 CFR

...unit. (d) The brake system shall be designed to prevent...apply to blended braking systems: (1) Loss of power or failure of the dynamic brake does not result in...electric portion of the brake system shall be displayed for...

2013-10-01

57

49 CFR 238.231 - Brake system.  

Code of Federal Regulations, 2012 CFR

...known that the air brake system is properly charged...blending of friction and dynamic brake to obtain the...automatic; (2) Loss of power or failure of the dynamic brake does not result...new designs of braking systems, the design...

2012-10-01

58

49 CFR 238.431 - Brake system.  

Code of Federal Regulations, 2012 CFR

...unit. (d) The brake system shall be designed to prevent...apply to blended braking systems: (1) Loss of power or failure of the dynamic brake does not result in...electric portion of the brake system shall be displayed for...

2012-10-01

59

49 CFR 238.231 - Brake system.  

Code of Federal Regulations, 2013 CFR

...known that the air brake system is properly charged...blending of friction and dynamic brake to obtain the...automatic; (2) Loss of power or failure of the dynamic brake does not result...new designs of braking systems, the design...

2013-10-01

60

49 CFR 238.431 - Brake system.  

Code of Federal Regulations, 2011 CFR

...unit. (d) The brake system shall be designed to prevent...apply to blended braking systems: (1) Loss of power or failure of the dynamic brake does not result in...electric portion of the brake system shall be displayed for...

2011-10-01

61

49 CFR 238.231 - Brake system.  

Code of Federal Regulations, 2011 CFR

...known that the air brake system is properly charged...blending of friction and dynamic brake to obtain the...automatic; (2) Loss of power or failure of the dynamic brake does not result...new designs of braking systems, the design...

2011-10-01

62

EXPERIMENTAL MODAL ANALYSIS OF BRAKE SQUEAL NOISE  

Microsoft Academic Search

Disc brake squeal noise continues to be the major problem concern for the automotive industry. In this paper, the brake squeal phenomenon of brake rotor disc had been investigated using experimental modal analysis (EMA). The modal analysis excitation technique known as impact hammer test has been carried out to obtain modal parameter of brake disc structure namely the natural frequencies

MUHAMMAD ZAHIR HASSAN

63

Regenerative braking device  

DOEpatents

Disclosed are several embodiments of a regenerative braking device for an automotive vehicle. The device includes a plurality of rubber rollers (24, 26) mounted for rotation between an input shaft (14) connectable to the vehicle drivetrain and an output shaft (16) which is drivingly connected to the input shaft by a variable ratio transmission (20). When the transmission ratio is such that the input shaft rotates faster than the output shaft, the rubber rollers are torsionally stressed to accumulate energy, thereby slowing the vehicle. When the transmission ratio is such that the output shaft rotates faster than the input shaft, the rubber rollers are torsionally relaxed to deliver accumulated energy, thereby accelerating or driving the vehicle.

Hoppie, Lyle O. (Birmingham, MI)

1982-01-12

64

Single acting translational/rotational brake  

NASA Technical Reports Server (NTRS)

A brake system is provided that applies braking forces on surfaces in both the translational and rotational directions using a single acting self-contained actuator that travels with the translational mechanism. The brake engages a mechanical lock and creates a frictional force on the translational structure preventing translation while simultaneously creating a frictional torque that prevents rotation of the vertical support. The system may include serrations on the braking surfaces to provide increased braking forces.

Allred, Johnny W. (Inventor); Fleck, Jr., Vincent J. (Inventor)

1996-01-01

65

Brake Stops Both Rotation And Translation  

NASA Technical Reports Server (NTRS)

Combination of braking and positioning mechanisms allows both rotation and translation before brake engaged. Designed for use in positioning model airplane in wind tunnel. Modified version used to position camera on tripod. Brake fast and convenient to use; contains single actuator energizing braking actions against both rotation and translation. Braking actuator electric, but pneumatic actuator could be used instead. Compact and lightweight, applies locking forces close to load, and presents minimal cross section to airflow.

Allred, Johnny W.; Fleck, Vincent J., Jr.

1995-01-01

66

49 CFR 570.56 - Vacuum brake assist unit and vacuum brake system.  

Code of Federal Regulations, 2011 CFR

...pedal. (1) Inspection procedure. Stop the engine and apply service brake several times to destroy vacuum in system. Depress the brake pedal with 50 pounds of force and while maintaining that force, start the engine. If the brake pedal does...

2011-10-01

67

AUTOMOTIVE DIESEL MAINTENANCE 2. UNIT IX, AUTOMATIC TRANSMISSIONS--HYDRAULIC SYSTEM (PART I).  

ERIC Educational Resources Information Center

THIS MODULE OF A 25-MODULE COURSE IS DESIGNED TO DEVELOP AN UNDERSTANDING OF THE OIL FLOW WITHIN HYDRAULIC TRANSMISSIONS USED ON DIESEL POWERED VEHICLES. TOPICS ARE GENERAL DESCRIPTION, HYDRAULIC CIRCUITS, AND BRAKE HYDRAULIC CIRCUIT AND OPERATION. THE MODULE CONSISTS OF A SELF-INSTRUCTIONAL PROGRAMED TRAINING FILM "LEARNING ABOUT THE ALLISON…

Human Engineering Inst., Cleveland, OH.

68

29 CFR 1919.22 - Requirements governing braking devices and power sources.  

Code of Federal Regulations, 2010 CFR

...power sources. All types of winches and cranes shall be provided with means to stop...hydraulic brakes at the winch, or electric cranes shall be equipped so that a failure...for operation of electric winches and cranes during the tests shall be taken from...

2010-07-01

69

Four-wheel dual braking for automobiles  

NASA Technical Reports Server (NTRS)

Each master cylinder applies braking power to all four wheels unlike conventional systems where cylinder operates only two wheels. If one master system fails because of fluid loss, other stops car by braking all four wheels although at half force.

Edwards, H. B.

1981-01-01

70

Piecewise polynomial chaos expansion with an application to brake squeal of a linear brake system  

E-print Network

are also inferred from these calculations. Keywords: brake squeal noise, stochastic, friction, eigenvalue problem 1. Introduction Brake squeal noise is a real problem for the automotive [1, 2] and railway [3Piecewise polynomial chaos expansion with an application to brake squeal of a linear brake system E

Paris-Sud XI, Université de

71

Compact, Lightweight Servo-Controllable Brakes  

NASA Technical Reports Server (NTRS)

Compact, lightweight servo-controllable brakes capable of high torques are being developed for incorporation into robot joints. A brake of this type is based partly on the capstan effect of tension elements. In a brake of the type under development, a controllable intermediate state of torque is reached through on/off switching at a high frequency.

Lovchik, Christopher S.; Townsend, William; Guertin, Jeffrey; Matsuoka, Yoky

2010-01-01

72

Statistical analysis of brake squeal noise  

Microsoft Academic Search

Despite substantial research efforts applied to the prediction of brake squeal noise since the early 20th century, the mechanisms behind its generation are still not fully understood. Squealing brakes are of significant concern to the automobile industry, mainly because of the costs associated with warranty claims. In order to remedy the problems inherent in designing quieter brakes and, therefore, to

S. Oberst; J. C. S. Lai

2011-01-01

73

Measuring Braking Indices for Young, Energetic Pulsars  

Microsoft Academic Search

Pulsar braking indices are only measurable for the very youngest of objects. In all cases, values less than 3 (for magnetic dipole radiation) have been reported. Due in large part to contamination from timing noise, values of the braking index or the second braking index for several of these objects have been called into question. We present an updated timing

M. A. Livingstone; V. M. Kaspi; F. P. Gavriil; R. N. Manchester

2004-01-01

74

Bidirectional drive and brake mechanism  

NASA Technical Reports Server (NTRS)

A space transport vehicle is disclosed as including a body which is arranged to be movably mounted on an elongated guide member disposed in outer space and driven therealong. A drive wheel is mounted on a drive shaft and arranged to be positioned in rolling engagement with the elongated guide carrying the vehicle. A brake member is arranged on the drive shaft for movement into and out of engagement with an adjacent surface of the drive wheel. An actuator is mounted on the body to be manually moved back and forth between spaced positions in an arc of movement. A ratchet-and-pawl mechanism is arranged to operate upon movements of the actuator in one direction between first and second positions for coupling the actuator to the drive wheel to incrementally rotate the wheel in one rotational direction and to operate upon movements of the actuator in the opposite direction for uncoupling the actuator from the wheel. The brake member is threadedly coupled to the drive shaft in order that the brake member will be operated only when the actuator is moved on beyond its first and second positions for shifting the brake member along the drive shaft and into frictional engagement with the adjacent surface on the drive wheel.

Swan, Scott A. (inventor)

1991-01-01

75

Brake blending strategy for a hybrid vehicle  

DOEpatents

A hybrid electric powertrain system is provided including a transmission for driving a pair of wheels of a vehicle and a heat engine and an electric motor/generator coupled to the transmission. A friction brake system is provided for applying a braking torque to said vehicle. A controller unit generates control signals to the electric motor/generator and the friction brake system for controllably braking the vehicle in response to a drivers brake command. The controller unit determines and amount of regenerative torque available and compares this value to a determined amount of brake torque requested for determining the control signals to the electric motor/generator and the friction brake system.

Boberg, Evan S. (Hazel Park, MI)

2000-12-05

76

Minimal models for squealing of railway block brakes  

Microsoft Academic Search

Block brakes have been used to brake railway vehicles for approximately 200 years. During the last 40 years, disk brakes have\\u000a replaced the block brakes at passenger cars but block brakes are still used for all freight wagons. One problem of block brakes\\u000a is that they show an enormous tendency to squeal. Although the block brake is a very common and old

Utz von Wagner; Gottfried Spelsberg-Korspeter

2011-01-01

77

ENVIRONMENTAL HYDRAULICS  

EPA Science Inventory

The thermal, chemical, and biological quality of water in rivers, lakes, reservoirs, and near coastal areas is inseparable from a consideration of hydraulic engineering principles: therefore, the term environmental hydraulics. In this chapter we discuss the basic principles of w...

78

49 CFR 570.57 - Air brake system and air-over-hydraulic brake subsystem.  

Code of Federal Regulations, 2010 CFR

...cuts in. Increased engine speed to fast idle and charge the system to its governed...cut-out position, in not more than 30 seconds for vehicles manufactured prior to...cuts in. Increase engine speed to fast idle and charge the system to its...

2010-10-01

79

49 CFR 570.57 - Air brake system and air-over-hydraulic brake subsystem.  

Code of Federal Regulations, 2012 CFR

...running at the manufacturer's maximum recommended number of revolutions per minute with the compressor governor in the cut-off...engine running at the manufacturer's recommended number of revolutions per minute and the compressor governor in the...

2012-10-01

80

49 CFR 570.57 - Air brake system and air-over-hydraulic brake subsystem.  

Code of Federal Regulations, 2011 CFR

...running at the manufacturer's maximum recommended number of revolutions per minute with the compressor governor in the cut-off...engine running at the manufacturer's recommended number of revolutions per minute and the compressor governor in the...

2011-10-01

81

49 CFR 570.57 - Air brake system and air-over-hydraulic brake subsystem.  

Code of Federal Regulations, 2013 CFR

...running at the manufacturer's maximum recommended number of revolutions per minute with the compressor governor in the cut-off...engine running at the manufacturer's recommended number of revolutions per minute and the compressor governor in the...

2013-10-01

82

Hydraulics Lectures  

NSDL National Science Digital Library

This page from the WindTech TV project provides a link to lectures created by Jim Pytel for his hydraulics course at Columbia Gorge Community College. The lectures consist of live videos and screen capture style presentations and may be viewed free of charge. Clicking on the video link in the center of the page will lead users to a YouTube page with 31 lectures. Topics include hydraulics math, hydraulic safety, basic hydraulic schematics, viscosity, piston pumps, actuators, troubleshooting and more. These lectures would be extremely useful for technical and community college students taking a fundamental hydraulics course. Flash is required to view the videos.

Pytel, Jim

83

A parametric study of perforated muzzle brakes  

NASA Astrophysics Data System (ADS)

A firing test was conducted to study the parameters influencing the recoil efficiency and the blast characteristics of perforated muzzle brakes. Several scaled (20 mm) devices were tested as candidates for the 105 mm Armored Gun System (AGS). Recoil impulse, blast overpressures, muzzle velocity, sequential spark shadowgraphs, and photographs of the muzzle flash were obtained. A total of nine different perforated brakes were tested as well as a scaled M 198 double muzzle brake.

Dillon, Robert E., Jr.; Nagamatsu, H. T.

1993-07-01

84

Bidirectional Drive-And-Brake Mechanism  

NASA Technical Reports Server (NTRS)

Vehicle that crawls along monorail combines features of both bicycle and railroad handcar. Bidirectional drive-and-brake mechanism includes selectable-pawl-and-ratchet overrunning clutch (drive mechanism) and mating stationary and rotating conical surfaces pressing against each other (brake mechanism). Operates similarly to bicycle drive-and-brake mechanism except limits rotation of sprocket in both directions and brakes at both limits. Conceived for use by astronaut traveling along structure in outer space, concept also applied on Earth to make very small railraod handcars or crawling vehicles for use on large structures, in pipelines under construction, or underwater.

Swan, Scott A.

1991-01-01

85

Dynamics of Braking Vehicles: From Coulomb Friction to Anti-Lock Braking Systems  

ERIC Educational Resources Information Center

The dynamics of braking of wheeled vehicles is studied using the Coulomb approximation for the friction between road and wheels. The dependence of the stopping distance on the mass of the vehicle, on the number of its wheels and on the intensity of the braking torque is established. It is shown that there are two regimes of braking, with and…

Tavares, J. M.

2009-01-01

86

Multidisciplinary design optimization of an automotive magnetorheological brake design  

E-print Network

Multidisciplinary design optimization of an automotive magnetorheological brake design Edward J This paper presents the development of a new electromechanical brake system using magnetorheological (MR: Magnetorheological fluid; Automotive brake; Finite element analysis; Computational fluid dynamics; Multidisciplinary

Park, Edward

87

A-REI Braking Distance  

NSDL National Science Digital Library

This is a task from the Illustrative Mathematics website that is one part of a complete illustration of the standard to which it is aligned. Each task has at least one solution and some commentary that addresses important asects of the task and its potential use. Here are the first few lines of the commentary for this task: Suppose that a particular model of car has a braking distance that can be computed as follows: When the car is traveling at $v$ miles per hour, its bra...

88

Landing and Braking of Airplanes  

NASA Technical Reports Server (NTRS)

In the numerical examples, we have considered an airplane landing in calm air in a fixed direction after crossing the border (with its obstacles) at a height of 30 m. Its stopping point is at a distance D from the obstacle, comprising: a distance D(sub 1) in regular gliding flight; a distance D(sub 2) in levelling off; a distance D(sub 3) in taxying on the ground. The calculations enable us to make out the following table, which gives an idea of the improvements to be expected in the use of various possible methods of braking in the air and on the ground.

Breguet, Louis

1929-01-01

89

Air brake-dynamometer accurately measures torque  

NASA Technical Reports Server (NTRS)

Air brake-dynamometer assembly combines the principles of the air turbine and the air pump to apply braking torque. The assembly absorbs and measures power outputs of rotating machinery over a wide range of shaft speeds. It can also be used as an air turbine.

1965-01-01

90

BRAKE SQUEAL NOISE: FINITE ELEMENT ANALYSIS  

Microsoft Academic Search

This paper investigated the brake disc squeal phenomenon using finite element analysis (FEA). The modal analysis has been used in this work to determine the natural frequency and mode shape pattern. The study on four different types of material properties is carried out to shows the effect of vibration mode and natural frequency as the source of brake squeal contribution.

MUHAMMAD ZAHIR HASSAN

91

Performance of a disc brake friction material  

Microsoft Academic Search

The friction materials used in brakes are required to provide a stable coefficient of friction and a lower wear rate at various operating speeds, pressures, temperatures and environmental conditions. These friction materials must also be compatible with the rotor material in order to reduce its extensive wear, vibration and noise during braking. All of these requirements need to be achieved

Pradnya Kosbe; Chittaranjan More

2010-01-01

92

Some wear studies on aircraft brake systems  

NASA Technical Reports Server (NTRS)

An initial investigation of worn surfaces in friction pads and steel rotors used in current aircraft brakes was carried out using electron microprobe and X-ray diffraction analysis. It consists of the topographical study and the analysis of chemical element distribution. Based upon this initial examination, two approaches, microscopic and macroscopic have been conducted to interpret and formulate the wear mechanism of the aircraft brake materials. Microscopically, the wear particles were examined. The initiation and growth of surface cracks and the oxidation were emphasized in this investigation. Macroscopically, it has been found that, for the current copper based brake material sliding against 17-22 AS steel in a caliper brake, the surface temperature raised due to frictional heat is nonlinearly proportional to the load applied and slide time with speed at 1750 rpm. The wear of brake materials is then proportional to this temperature and is also a function of the melting temperature for copper.

Ho, T. L.

1975-01-01

93

Hydraulic Car  

NSDL National Science Digital Library

In this activity, learners build cars using syringes and water-powered hydraulics. Learners construct the car frame out of cardboard and set up a hydraulic system to raise and lower the car. Use this project to introduce learners to incompressible fluids and Pascal's Principle.

2014-09-12

94

Method and apparatus for electromagnetically braking a motor  

NASA Technical Reports Server (NTRS)

An electromagnetic braking system and method is provided for selectively braking a motor using an electromagnetic brake having an electromagnet, a permanent magnet, a rotor assembly, and a brake pad. The brake assembly applies when the electromagnet is de-energized and releases when the electromagnet is energized. When applied the permanent magnet moves the brake pad into frictional engagement with a housing, and when released the electromagnet cancels the flux of the permanent magnet to allow a leaf spring to move the brake pad away from the housing. A controller has a DC/DC converter for converting a main bus voltage to a lower braking voltage based on certain parameters. The converter utilizes pulse-width modulation (PWM) to regulate the braking voltage. A calibrated gap is defined between the brake pad and permanent magnet when the brake assembly is released, and may be dynamically modified via the controller.

Davis, Donald R. (Inventor); Radford, Nicolaus A (Inventor); Permenter, Frank Noble (Inventor); Parsons, Adam H (Inventor); Mehling, Joshua S (Inventor)

2011-01-01

95

Brake wear particle emissions: a review.  

PubMed

Traffic-related sources have been recognized as a significant contributor of particulate matter particularly within major cities. Exhaust and non-exhaust traffic-related sources are estimated to contribute almost equally to traffic-related PM10 emissions. Non-exhaust particles can be generated either from non-exhaust sources such as brake, tyre, clutch and road surface wear or already exist in the form of deposited material at the roadside and become resuspended due to traffic-induced turbulence. Among non-exhaust sources, brake wear can be a significant particulate matter (PM) contributor, particularly within areas with high traffic density and braking frequency. Studies mention that in urban environments, brake wear can contribute up to 55 % by mass to total non-exhaust traffic-related PM10 emissions and up to 21 % by mass to total traffic-related PM10 emissions, while in freeways, this contribution is lower due to lower braking frequency. As exhaust emissions control become stricter, relative contributions of non-exhaust sources-and therefore brake wear-to traffic-related emissions will become more significant and will raise discussions on possible regulatory needs. The aim of the present literature review study is to present the state-of-the-art of the different aspects regarding PM resulting from brake wear and provide all the necessary information in terms of importance, physicochemical characteristics, emission factors and possible health effects. PMID:25318420

Grigoratos, Theodoros; Martini, Giorgio

2015-02-01

96

49 CFR 393.43 - Breakaway and emergency braking.  

Code of Federal Regulations, 2010 CFR

...Every truck or truck tractor equipped with air...emergency features of the trailer brakes. One...brakes. Every truck tractor and truck when used...operate all brakes of the combination, a second manual...braking requirements for trailers. Every trailer...

2010-10-01

97

Statistical analysis of brake squeal noise  

NASA Astrophysics Data System (ADS)

Despite substantial research efforts applied to the prediction of brake squeal noise since the early 20th century, the mechanisms behind its generation are still not fully understood. Squealing brakes are of significant concern to the automobile industry, mainly because of the costs associated with warranty claims. In order to remedy the problems inherent in designing quieter brakes and, therefore, to understand the mechanisms, a design of experiments study, using a noise dynamometer, was performed by a brake system manufacturer to determine the influence of geometrical parameters (namely, the number and location of slots) of brake pads on brake squeal noise. The experimental results were evaluated with a noise index and ranked for warm and cold brake stops. These data are analysed here using statistical descriptors based on population distributions, and a correlation analysis, to gain greater insight into the functional dependency between the time-averaged friction coefficient as the input and the peak sound pressure level data as the output quantity. The correlation analysis between the time-averaged friction coefficient and peak sound pressure data is performed by applying a semblance analysis and a joint recurrence quantification analysis. Linear measures are compared with complexity measures (nonlinear) based on statistics from the underlying joint recurrence plots. Results show that linear measures cannot be used to rank the noise performance of the four test pad configurations. On the other hand, the ranking of the noise performance of the test pad configurations based on the noise index agrees with that based on nonlinear measures: the higher the nonlinearity between the time-averaged friction coefficient and peak sound pressure, the worse the squeal. These results highlight the nonlinear character of brake squeal and indicate the potential of using nonlinear statistical analysis tools to analyse disc brake squeal.

Oberst, S.; Lai, J. C. S.

2011-06-01

98

Wear studies on aircraft brake materials  

NASA Technical Reports Server (NTRS)

An investigation of both worn surfaces of friction pads and steel rotors which are being applied in current aircraft brakes has been carried out by employing an X-ray diffraction technique. It consists of the analysis of chemical element distribution in the surface layers. The wear particles were also examined by using the scanning electron microscope. The initiation and growth of surface cracks and the oxidation were emphasized in this investigation. A wear model was proposed for the current aircraft brake materials. Essentially this model proposed that cracks are formed in the surface layer of the brake material due to the normal and frictional stresses. It is primarily surface temperature dependent.

Ho, T. L.

1977-01-01

99

Performance of an aircraft tire under cyclic braking and of a currently operational antiskid braking system  

NASA Technical Reports Server (NTRS)

An experimental investigation was conducted to study the performance of an aircraft tire under cyclic braking conditions and to study the performance of a currently operational aircraft antiskid braking system. Dry, damp, and flooded runway surface conditions were used in the investigation. The results indicated that under cyclic braking conditions the braking and cornering-force friction coefficients may be influenced by fluctuations in the vertical load, flexibility in the wheel support, and the spring coupling between the wheel and the tire-pavement interface. The cornering capability was shown to be negligible at wheel slip ratios well below a locked-wheel skid under all test surface conditions. The maximum available brake-force friction coefficient was shown to be dependent upon the runway surface condition, upon velocity, and, for wet runways, upon tire differences. Moderate reductions in vertical load and brake system pressure did not significantly affect the overall wet-runway performance of the tire.

Tanner, J. A.

1972-01-01

100

Rotary Speed Sensor for Antilocking Brakes  

NASA Technical Reports Server (NTRS)

Sensor based on fluidic principles produces negative pressure approximately proportional to rotational speed. Sensor developed as part of antilocking brake system for motorcycles. Uses inlet pressure rather than outlet pressure as braking-control signal, eliminating pressure pulsations caused by pump vanes and ensuring low-noise signal. Sensor is centrifugal air pump turned by one of motorcycle wheels. Air enters pump through orifice plates, and suction taken off through port in pump inlet plenum.

Berdahl, C. M.

1986-01-01

101

Oscillatory flow braking: inner magnetosphere observations  

NASA Astrophysics Data System (ADS)

We search for damped oscillatory flow braking events observed by THEMIS/ARTEMIS in the near-Earth plasma sheet when their counterpart in the inner magnetosphere was observed. By comparing the particle and magnetic field data in the two locations we analyze the feedback of the inner magnetosphere to plasma sheet oscillatory flow braking. We discuss the possible role of the oscillatory flow events for plasma injection into the inner magnetosphere.

Panov, E. V.; Nakamura, R.; Baumjohann, W.; Angelopoulos, V.

2013-12-01

102

Modelling and validation of magnetorheological brake responses using parametric approach  

NASA Astrophysics Data System (ADS)

Magnetorheological brake (MR Brake) is one x-by-wire systems which performs better than conventional brake systems. MR brake consists of a rotating disc that is immersed with Magnetorheological Fluid (MR Fluid) in an enclosure of an electromagnetic coil. The applied magnetic field will increase the yield strength of the MR fluid where this fluid was used to decrease the speed of the rotating shaft. The purpose of this paper is to develop a mathematical model to represent MR brake with a test rig. The MR brake model is developed based on actual torque characteristic which is coupled with motion of a test rig. Next, the experimental are performed using MR brake test rig and obtained three output responses known as angular velocity response, torque response and load displacement response. Furthermore, the MR brake was subjected to various current. Finally, the simulation results of MR brake model are then verified with experimental results.

Z, Zainordin A.; A, Abdullah M.; K, Hudha

2013-12-01

103

Brake squeal reduction of vehicle disc brake system with interval parameters by uncertain optimization  

NASA Astrophysics Data System (ADS)

An uncertain optimization method for brake squeal reduction of vehicle disc brake system with interval parameters is presented in this paper. In the proposed method, the parameters of frictional coefficient, material properties and the thicknesses of wearing components are treated as uncertain parameters, which are described as interval variables. Attention is focused on the stability analysis of a brake system in squeal, and the stability of brake system is investigated via the complex eigenvalue analysis (CEA) method. The dominant unstable mode is extracted by performing CEA based on a linear finite element (FE) model, and the negative damping ratio corresponding to the dominant unstable mode is selected as the indicator of instability. The response surface method (RSM) is applied to approximate the implicit relationship between the unstable mode and the system parameters. A reliability-based optimization model for improving the stability of the vehicle disc brake system with interval parameters is constructed based on RSM, interval analysis and reliability analysis. The Genetic Algorithm is used to get the optimal values of design parameters from the optimization model. The stability analysis and optimization of a disc brake system are carried out, and the results show that brake squeal propensity can be reduced by using stiffer back plates. The proposed approach can be used to improve the stability of the vehicle disc brake system with uncertain parameters effectively.

Lü, Hui; Yu, Dejie

2014-12-01

104

Experimental analysis of brake squeal noise on a laboratory brake setup  

Microsoft Academic Search

The present paper is the first of two papers dealing with brake squeal instability. An experimental setup is specifically designed for this purpose and is characterized by a simple design to aid measurements and modeling. This first paper describes the experimental setup called “laboratory brake” and presents the measurements performed on it to characterize its dynamical behavior and its squeal

Oliviero Giannini; Adnan Akay; Francesco Massi

2006-01-01

105

Magnetic braking in galactic flows  

SciTech Connect

The nuclear fireworks of active galaxies are believed to derive their power from the kinetic energy of gas falling onto a massive central objects; mass shed from evolving galactic stars is an obvious source of fuel for this process. But this ejected material shares the galactic rotation, and a centrifugal barrier will prevent it from reaching the nucleus, if its angular momentum is not removed. This paper shows that, if the large-scale galactic magnetic field has a strong enough radial component, magnetic torques can act to spin down the infalling matter. Rotation of the interstellar gas induces a toroidal magnetic field, and Maxwell stresses remove angular momentum from the flow; gas can then fall inward to the galactic center. In this way, the monster in the nucleus can be fed on gas from a galaxy's own stars. The magnetic fields in M87 and NGC 1275, giant elliptical galaxies which are accreting from an intracluster medium, appear to be strong enough to allow magnetic braking.

Sparke, L.S.

1982-09-01

106

Hydraulic system for a ratio change transmission  

DOEpatents

Disclosed is a drive assembly (10) for an electrically powered vehicle (12). The assembly includes a transaxle (16) having a two-speed transmission (40) and a drive axle differential (46) disposed in a unitary housing assembly (38), an oil-cooled prime mover or electric motor (14) for driving the transmission input shaft (42), an adapter assembly (24) for supporting the prime mover on the transaxle housing assembly, and a hydraulic system (172) providing pressurized oil flow for cooling and lubricating the electric motor and transaxle and for operating a clutch (84) and a brake (86) in the transmission to shift between the two-speed ratios of the transmission. The adapter assembly allows the prime mover to be supported in several positions on the transaxle housing. The brake is spring-applied and locks the transmission in its low-speed ratio should the hydraulic system fail. The hydraulic system pump is driven by an electric motor (212) independent of the prime mover and transaxle.

Kalns, Ilmars (Northville, MI)

1981-01-01

107

Adaptive controller for regenerative and friction braking system  

DOEpatents

A regenerative and friction braking system for a vehicle having one or more roadwheels driven by an electric traction motor includes a driver responsive device for producing a brake demand signal having a magnitude corresponding to the level of braking force selected by the driver and friction and regenerative brakes operatively connected with the roadwheels of the vehicle. A system according to this invention further includes control means for operating the friction and regenerative braking subsystems so that maximum brake torques sustainable by the roadwheels of the vehicle without skidding or slipping will not be exceeded.

Davis, Roy I. (Ypsilanti, MI)

1990-01-01

108

Adaptive controller for regenerative and friction braking system  

DOEpatents

A regenerative and friction braking system for a vehicle having one or more road wheels driven by an electric traction motor includes a driver responsive device for producing a brake demand signal having a magnitude corresponding to the level of braking force selected by the driver and friction and regenerative brakes operatively connected with the road wheels of the vehicle. A system according to this invention further includes control means for operating the friction and regenerative braking subsystems so that maximum brake torques sustainable by the road wheels of the vehicle without skidding or slipping will not be exceeded. 8 figs.

Davis, R.I.

1990-10-16

109

Modeling hydraulic regenerative hybrid vehicles using AMESim and Matlab/Simulink  

NASA Astrophysics Data System (ADS)

This paper presents the overview of the simulation modeling of a hydraulic system with regenerative braking used to improve vehicle emissions and fuel economy. Two simulation software packages were used together to enhance the simulation capability for fuel economy results and development of vehicle and hybrid control strategy. AMESim, a hydraulic simulation software package modeled the complex hydraulic circuit and component hardware and was interlinked with a Matlab/Simulink model of the vehicle, engine and the control strategy required to operate the vehicle and the hydraulic hybrid system through various North American and European drive cycles.

Lynn, Alfred; Smid, Edzko; Eshraghi, Moji; Caldwell, Niall; Woody, Dan

2005-05-01

110

THERMAL HYDRAULICS KEYWORDS: thermal hydraulics,  

E-print Network

-fluid modeling of nuclear reactor systems. Thermal-hydraulic analysis codes such as RELAP5-3D ~Ref. 1! and FLICA regions of the system. In fact, the CFD code FLUENT has previously been coupled to RELAP5-3D ~Refs. 3

Smith, Barton L.

111

49 CFR 570.59 - Service brake system.  

Code of Federal Regulations, 2013 CFR

...the condition indicated, measuring as necessary. (c) Friction materials. On each brake, the thickness of the lining...The wire in wire-backed lining shall not be visible on the friction surface. Drum brake linings shall be securely attached...

2013-10-01

112

49 CFR 570.59 - Service brake system.  

Code of Federal Regulations, 2010 CFR

...the condition indicated, measuring as necessary. (c) Friction materials. On each brake, the thickness of the lining...The wire in wire-backed lining shall not be visible on the friction surface. Drum brake linings shall be securely attached...

2010-10-01

113

14 CFR 23.493 - Braked roll conditions.  

Code of Federal Regulations, 2010 CFR

...CATEGORY AIRPLANES Structure Ground Loads § 23.493 Braked roll conditions. Under braked roll conditions, with the shock absorbers and tires in their static positions, the following apply: (a) The limit vertical load factor must be...

2010-01-01

114

14 CFR 23.493 - Braked roll conditions.  

Code of Federal Regulations, 2011 CFR

...CATEGORY AIRPLANES Structure Ground Loads § 23.493 Braked roll conditions. Under braked roll conditions, with the shock absorbers and tires in their static positions, the following apply: (a) The limit vertical load factor must be...

2011-01-01

115

14 CFR 27.493 - Braked roll conditions.  

Code of Federal Regulations, 2010 CFR

...ROTORCRAFT Strength Requirements Ground Loads § 27.493 Braked roll conditions. Under braked roll conditions with the shock absorbers in their static positions— (a) The limit vertical load must be based on a load factor of at least—...

2010-01-01

116

14 CFR 27.493 - Braked roll conditions.  

Code of Federal Regulations, 2011 CFR

...ROTORCRAFT Strength Requirements Ground Loads § 27.493 Braked roll conditions. Under braked roll conditions with the shock absorbers in their static positions— (a) The limit vertical load must be based on a load factor of at least—...

2011-01-01

117

14 CFR 29.493 - Braked roll conditions.  

Code of Federal Regulations, 2010 CFR

...ROTORCRAFT Strength Requirements Ground Loads § 29.493 Braked roll conditions. Under braked roll conditions with the shock absorbers in their static positions— (a) The limit vertical load must be based on a load factor of at least—...

2010-01-01

118

49 CFR 570.58 - Electric brake system.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Electric brake system. 570.58 ...DEPARTMENT OF TRANSPORTATION VEHICLE IN USE INSPECTION STANDARDS Vehicles With GVWR of More Than 10,000 Pounds § 570.58 Electric brake system. (a)...

2013-10-01

119

49 CFR 570.58 - Electric brake system.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 false Electric brake system. 570.58 ...DEPARTMENT OF TRANSPORTATION VEHICLE IN USE INSPECTION STANDARDS Vehicles With GVWR of More Than 10,000 Pounds § 570.58 Electric brake system. (a)...

2010-10-01

120

49 CFR 570.58 - Electric brake system.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Electric brake system. 570.58 ...DEPARTMENT OF TRANSPORTATION VEHICLE IN USE INSPECTION STANDARDS Vehicles With GVWR of More Than 10,000 Pounds § 570.58 Electric brake system. (a)...

2011-10-01

121

49 CFR 570.58 - Electric brake system.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false Electric brake system. 570.58 ...DEPARTMENT OF TRANSPORTATION VEHICLE IN USE INSPECTION STANDARDS Vehicles With GVWR of More Than 10,000 Pounds § 570.58 Electric brake system. (a)...

2012-10-01

122

49 CFR 570.5 - Service brake system.  

Code of Federal Regulations, 2010 CFR

...Measure the distance (A) from the free pedal position to the floorboard or other object that restricts brake pedal travel. Depress the brake pedal, and with the force applied measure the distance (B) from the depressed pedal position to the...

2010-10-01

123

49 CFR 570.5 - Service brake system.  

Code of Federal Regulations, 2011 CFR

...Measure the distance (A) from the free pedal position to the floorboard or other object that restricts brake pedal travel. Depress the brake pedal, and with the force applied measure the distance (B) from the depressed pedal position to the...

2011-10-01

124

30 CFR 75.1404-1 - Braking system.  

Code of Federal Regulations, 2010 CFR

...Hoisting and Mantrips § 75.1404-1 Braking system. A locomotive equipped with a dual braking system will be deemed to satisfy the requirements of § 75.1404 for a train comprised of such locomotive and...

2010-07-01

125

30 CFR 77.1401 - Automatic controls and brakes.  

...Hoisting § 77.1401 Automatic controls and brakes. Hoists and elevators shall be equipped with overspeed, overwind, and automatic stop controls and with brakes capable of stopping the elevator when fully...

2014-07-01

126

30 CFR 77.1401 - Automatic controls and brakes.  

Code of Federal Regulations, 2011 CFR

...Hoisting § 77.1401 Automatic controls and brakes. Hoists and elevators shall be equipped with overspeed, overwind, and automatic stop controls and with brakes capable of stopping the elevator when fully...

2011-07-01

127

30 CFR 77.1401 - Automatic controls and brakes.  

Code of Federal Regulations, 2013 CFR

...Hoisting § 77.1401 Automatic controls and brakes. Hoists and elevators shall be equipped with overspeed, overwind, and automatic stop controls and with brakes capable of stopping the elevator when fully...

2013-07-01

128

30 CFR 77.1401 - Automatic controls and brakes.  

Code of Federal Regulations, 2012 CFR

...Hoisting § 77.1401 Automatic controls and brakes. Hoists and elevators shall be equipped with overspeed, overwind, and automatic stop controls and with brakes capable of stopping the elevator when fully...

2012-07-01

129

49 CFR 238.309 - Periodic brake equipment maintenance.  

Code of Federal Regulations, 2013 CFR

...STANDARDS Inspection, Testing, and Maintenance Requirements...equipment's brake system pneumatic components that contain...equipment and brake cylinders of each DMU or MU...cleaning, repairing, and testing required by this...cleaning, repairing, and testing and maintain an...

2013-10-01

130

49 CFR 238.309 - Periodic brake equipment maintenance.  

Code of Federal Regulations, 2012 CFR

...STANDARDS Inspection, Testing, and Maintenance Requirements...equipment's brake system pneumatic components that contain...equipment and brake cylinders of each DMU or MU...cleaning, repairing, and testing required by this...cleaning, repairing, and testing and maintain an...

2012-10-01

131

30 CFR 75.1404 - Automatic brakes; speed reduction gear.  

...false Automatic brakes; speed reduction gear. 75.1404 Section 75.1404...1404 Automatic brakes; speed reduction gear. [Statutory Provisions...cars shall be subject to speed reduction gear, or other similar devices...

2014-07-01

132

30 CFR 75.1404 - Automatic brakes; speed reduction gear.  

Code of Federal Regulations, 2012 CFR

...false Automatic brakes; speed reduction gear. 75.1404 Section 75.1404...1404 Automatic brakes; speed reduction gear. [Statutory Provisions...cars shall be subject to speed reduction gear, or other similar devices...

2012-07-01

133

2. OBLIQUE VIEW OF HOIST, SHOWING CABLE DRUM, WOODEN BRAKE ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

2. OBLIQUE VIEW OF HOIST, SHOWING CABLE DRUM, WOODEN BRAKE SHOES, BRAKE HANDLE, AND REDUCTION GEARS, LOOKING SOUTHWEST - Buffalo Coal Mine, Vulcan Cable Hoist, Wishbone Hill, Southeast end, near Moose Creek, Sutton, Matanuska-Susitna Borough, AK

134

30 CFR 75.1404 - Automatic brakes; speed reduction gear.  

Code of Federal Regulations, 2013 CFR

...false Automatic brakes; speed reduction gear. 75.1404 Section 75.1404...1404 Automatic brakes; speed reduction gear. [Statutory Provisions...cars shall be subject to speed reduction gear, or other similar devices...

2013-07-01

135

30 CFR 75.1404 - Automatic brakes; speed reduction gear.  

Code of Federal Regulations, 2011 CFR

...false Automatic brakes; speed reduction gear. 75.1404 Section 75.1404...1404 Automatic brakes; speed reduction gear. [Statutory Provisions...cars shall be subject to speed reduction gear, or other similar devices...

2011-07-01

136

30 CFR 75.1404 - Automatic brakes; speed reduction gear.  

Code of Federal Regulations, 2010 CFR

...false Automatic brakes; speed reduction gear. 75.1404 Section 75.1404...1404 Automatic brakes; speed reduction gear. [Statutory Provisions...cars shall be subject to speed reduction gear, or other similar devices...

2010-07-01

137

Nonlinear stability analysis of a disk brake model  

Microsoft Academic Search

It has become commonly accepted by scientists and engineers that brake squeal is generated by friction-induced self-excited\\u000a vibrations of the brake system. The noise-free configuration of the brake system loses stability through a flutter-type instability\\u000a and the system starts oscillating in a limit cycle. Usually, the stability analysis of disk brake models, both analytical\\u000a as well as finite element based,

Daniel Hochlenert

2009-01-01

138

Improvements in the inspection procedure of brake disc warping  

Microsoft Academic Search

\\u000a Abstract  The warping of brake discs and ovality of brake drums is one of the main causes of vibration and noise during the braking\\u000a of a vehicle and of diminishing brake efficiency. Nowadays, the International Motor Vehicle Inspection Committee (CITA) demands\\u000a an inspection of the warping and ovality during the Periodic Motor Vehicle Inspection (PMVI). However, the measurement is\\u000a not always

D. García-Pozuelo; A. Gauchía; B. L. Boada; V. Díaz

2009-01-01

139

Motion capture of a pad measured with accelerometers during squeal noise in a real brake system  

NASA Astrophysics Data System (ADS)

The operating deflection shape of a pad during squeal noise is measured on a real brake system with three-axis accelerometers. A time-frequency analysis is performed that highlights the dependency of squeal on the hydraulic pressure of the system and shows that squeal occurs simultaneously with harmonic components. The operating deflection shape of this pad before and during squeal is then visualized using interpolation, showing the predominance of bending motion. Finally, the pad motions observed are compared to the real modal basis of a detailed Finite Element model.

Renaud, Franck; Chevallier, Gaël; Dion, Jean-Luc; Taudière, Guillaume

2012-11-01

140

The braking indices in pulsar emission models  

E-print Network

Using the method proposed in a previous paper, we calculate pulsar braking indices in the models with torque contributions from both inner and outer accelerating regions, assuming that the interaction between them is negligible. We suggest that it is likely that the inverse Compton scattering induced polar vacuum gap and the outer gap coexist in the pulsar magnetosphere. We include the new near threshold vacuum gap models with curvature-radiation and inverse Compton scattering induced cascades, respectively; and find that these models can well reproduce the measured values of the braking indices.

F. Wu; R. X. Xu; Janusz Gil

2003-08-23

141

49 CFR 232.305 - Single car air brake tests.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false Single car air brake tests. 232.305 Section 232.305...and Testing Requirements § 232.305 Single car air brake tests. (a) Single car air brake tests shall be performed by a...

2012-10-01

142

49 CFR 232.305 - Single car air brake tests.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Single car air brake tests. 232.305 Section 232.305...and Testing Requirements § 232.305 Single car air brake tests. (a) Single car air brake tests shall be performed by a...

2013-10-01

143

49 CFR 570.6 - Brake power unit.  

Code of Federal Regulations, 2011 CFR

...visually and aurally for conditions indicated. Stop engine and apply service brakes several times to destroy vacuum in system. Depress brake pedal with 25 pounds of force and while maintaining that force, start the engine. If brake pedal does not fall...

2011-10-01

144

49 CFR 570.6 - Brake power unit.  

Code of Federal Regulations, 2010 CFR

...visually and aurally for conditions indicated. Stop engine and apply service brakes several times to destroy vacuum in system. Depress brake pedal with 25 pounds of force and while maintaining that force, start the engine. If brake pedal does not fall...

2010-10-01

145

Predictive model of squeal noise occurring on a laboratory brake  

Microsoft Academic Search

This paper on brake squeal instability presents a reduced order model of a laboratory brake considered in a previous paper, and presents a description of the squeal mechanism occurring during experiments.The model uses the modal parameters of the laboratory brake components, the disc and the caliper, when they are not in contact between them. Successively, the caliper and the disc

Oliviero Giannini; Aldo Sestieri

2006-01-01

146

Design Restrictions Ground clearance Brake components cannot contact  

E-print Network

braking. The brake must not stop so suddenly that the rider is thrown forward off of the skateboard Introduction Skateboarding can be fun but it is dangerous. Novice riders and commuters can find it difficult. Acknowledgments Max Sorenson GoEngineer Millcreek Bicycles Milosports Brake Materials and Parts Inc Skateboard

Provancher, William

147

49 CFR 232.305 - Single car air brake tests.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 false Single car air brake tests. 232.305 Section 232.305...and Testing Requirements § 232.305 Single car air brake tests. (a) Single car air brake tests shall be performed by a...

2010-10-01

148

49 CFR 232.305 - Single car air brake tests.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Single car air brake tests. 232.305 Section 232.305...and Testing Requirements § 232.305 Single car air brake tests. (a) Single car air brake tests shall be performed by a...

2011-10-01

149

30 CFR 56.14102 - Brakes for rail equipment.  

...Resources 1 2014-07-01 2014-07-01 false Brakes for rail equipment. 56.14102 Section 56.14102 Mineral Resources...Devices and Maintenance Requirements § 56.14102 Brakes for rail equipment. Braking systems on railroad cars and...

2014-07-01

150

30 CFR 57.14102 - Brakes for rail equipment.  

...Resources 1 2014-07-01 2014-07-01 false Brakes for rail equipment. 57.14102 Section 57.14102 Mineral Resources...Devices and Maintenance Requirements § 57.14102 Brakes for rail equipment. Braking systems on railroad cars and...

2014-07-01

151

Development and modelling of an electropneumatic brake system  

Microsoft Academic Search

The brake system is the primary system in an automobile which ensures its safety on the road. The ideal brake system should operate with the least effort from the driver and should stop the vehicle within the minimum possible distance. This paper deals with the air brake system which is widely used in commercial vehicles such as trucks, buses and

P. Karthikeyan; Shankar C. Subramanian

2009-01-01

152

30 CFR 75.1400-1 - Hoists; brakes, capability.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Hoists; brakes, capability. 75.1400-1 Section 75.1400-1 Mineral Resources...Hoisting and Mantrips § 75.1400-1 Hoists; brakes, capability. Brakes on hoists used to transport persons shall be...

2010-07-01

153

30 CFR 75.1400-1 - Hoists; brakes, capability.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 false Hoists; brakes, capability. 75.1400-1 Section 75.1400-1 Mineral Resources...Hoisting and Mantrips § 75.1400-1 Hoists; brakes, capability. Brakes on hoists used to transport persons shall be...

2011-07-01

154

49 CFR 236.508 - Interference with application of brakes by means of brake valve.  

Code of Federal Regulations, 2013 CFR

...AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Automatic Train Stop, Train Control and Cab Signal Systems Standards § 236.508 ...means of brake valve. The automatic train stop, train...

2013-10-01

155

49 CFR 236.508 - Interference with application of brakes by means of brake valve.  

Code of Federal Regulations, 2011 CFR

...AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Automatic Train Stop, Train Control and Cab Signal Systems Standards § 236.508 ...means of brake valve. The automatic train stop, train...

2011-10-01

156

The design of aircraft brake systems, employing cooling to increase brake life  

NASA Technical Reports Server (NTRS)

A research program was initiated to determine the feasibility of using cooling to increase brake life. An air cooling scheme was proposed, constructed and tested with various designs. Straight and curved slotting of the friction material was tested. A water cooling technique, similar to the air cooling procedure, was evaluated on a curved slotted rotor. Also investigated was the possibility of using a phase-change material within the rotor to absorb heat during braking. Various phase-changing materials were tabulated and a 50%, (by weight) LiF - BeF2 mixing was chosen. It was shown that corrosion was not a problem with this mixture. A preliminary design was evaluated on an actual brake. Results showed that significant improvements in lowering the surface temperature of the brake occurred when air or water cooling was used in conjunction with curved slotted rotors.

Scaringe, R. P.; Ho, T. L.; Peterson, M. B.

1975-01-01

157

Electromechanical steering, suspension, drive and brake modules  

Microsoft Academic Search

Qualified chassis control is enabled by utilizing the modular alignment, load and torque concept described in this paper. The most advanced vehicle design incorporates mechanically identical wheel corners, each with individually powered and computer regulated propulsion, braking, steering, spring and damper functions. The suspension arms are mechanically attached to the body; all other interfaces are by-wire. In-wheel motors, actuators and

S. Zetterstrom

2002-01-01

158

Measurements of radio pulsar braking indices  

NASA Astrophysics Data System (ADS)

A quantitative analysis of radio pulsar timing noise is presented. Our analysis employs the recently reported strong correlation (with correlation coefficient r = 0.95) between the observed second time derivative of the pulse rotation frequency (ddot?obs), obtained from fully phase-coherent timing analyses, and a timing noise statistic (?R23), used to quantify the amount of pulsar rotational fluctuations absorbed by the coefficient of the cubic term, to isolate the presumed deterministic braking index from the effects attributable to pulsar timing activity. Application of this method to a sample of 27 radio pulsars, whose timing data span 9-13 years, reveals that (i) for 22 pulsars, a sensible braking index measurement was impossible: with numerical values of the braking index either appreciably less than the corresponding uncertainty or anomalously large; (ii) save for the relatively large uncertainties, the braking index appears to be significantly measured in five pulsars. Current results are discussed in the context of the prevailing standard model for radio pulsar spin-down.

Chukwude, A. E.; Baiden, A. A.; Onuchukwu, C. C.

2010-06-01

159

Contactless magnetic brake for automotive applications  

E-print Network

of theoretical analysis ....................................................... 78 III FINITE ELEMENT ANALYSIS OF EDDY-CURRENT BRAKING .. 81 1 Fundamentals of finite element analysis .............................................. 81 2 Selection... of finite-element analysis method ........................................ 82 3 Comparison of analytical and finite-element results............................ 90 4 Analysis of the impact of design parameters on performance ............. 95 4...

Gay, Sebastien Emmanuel

2009-05-15

160

Clamping-Force Control for Electromechanical Brake  

Microsoft Academic Search

The estimation of the frictional and clamping forces is one of the key issues in the design and implementation of the electromechanical brake (EMB) system. In this paper, a clamping-force control algorithm is presented along with a consideration of the frictional characteristics and the estimation of the clamping force for a planetary reduction gear-type EMB. The frictional model is developed

Chihoon Jo; Sungho Hwang; Hyunsoo Kim

2010-01-01

161

14 CFR 23.735 - Brakes.  

... (2) Instead of a rational analysis, the kinetic...configuration; and N=Number of main wheels with brakes...based on a conservative rational analysis of the sequence... (2) Instead of a rational analysis, the kinetic...51(c)(1); N = Number of main wheels with...

2014-01-01

162

14 CFR 23.735 - Brakes.  

Code of Federal Regulations, 2013 CFR

... (2) Instead of a rational analysis, the kinetic...configuration; and N=Number of main wheels with brakes...based on a conservative rational analysis of the sequence... (2) Instead of a rational analysis, the kinetic...51(c)(1); N = Number of main wheels with...

2013-01-01

163

Hybrid Electric Vehicle (HEV) Braking and Steering Systems  

NSDL National Science Digital Library

This module consists of a PowerPoint presentation, lab sheet, and syllabi discussing HEVs' braking and steering systems. These materials are derived from three courses offered at Lewis and Clark Community College on automotive alignment, braking, and steering systems and were developed through a seed grant from the CAAT. The presentation discusses the circuitry and operations for HEV braking and steering systems, variations from traditional braking and steering power assist, and how to service brake pads on a Ford Escape Hybrid. The lab sheet should familiarize students with the variations and similarities between hybrid and conventional systems when servicing a HEV's brake pads such as placing the vehicle in âPad Service Mode.â The provided syllabi includes highlighted sections where these HEV technologies were incorporated into alignment, brakes, and suspension courses at Lewis and Clark Community College.

College, Lewis A.

164

Hydraulic fracturing-1  

SciTech Connect

This book contains papers on hydraulic fracturing. Topics covered include: An overview of recent advances in hydraulic fracturing technology; Containment of massive hydraulic fracture; and Fracturing with a high-strength proppant.

Not Available

1990-01-01

165

A method to achieve comparable thermal states of car brakes during braking on the road and on a high-speed roll-stand  

NASA Astrophysics Data System (ADS)

The temperature of a brake friction surface influences significantly the braking effectiveness. The paper describes a heat transfer process in car brakes. Using a developed program of finite element method, the temperature distributions in brake rotors (disc and drum brake) of a light truck have been calculated. As a preliminary consistency criterion of the brake thermal state in road and roll-stand braking conditions, a balance of the energy cumulated in the brake rotor has been taken into account. As the most reliable consistency criterion an equality of average temperatures of the friction surface has been assumed. The presented method allows to achieve on a roll-stand the analogical thermal states of automotive brakes, which are observed during braking in road conditions. Basing on this method, it is possible to calculate the braking time and force for a high-speed roll-stand. In contrast to the previous papers of the author, new calculation results have been presented.

Wolff, Andrzej

2010-01-01

166

49 CFR 238.15 - Movement of passenger equipment with power brake defects.  

Code of Federal Regulations, 2011 CFR

...which addresses brakes that become defective en route after a Class I or IA brake test...passenger service that becomes defective en route after a Class I or IA brake test...brakes or any other power brake defect while en route to another location after...

2011-10-01

167

49 CFR 238.15 - Movement of passenger equipment with power brake defects.  

Code of Federal Regulations, 2010 CFR

...which addresses brakes that become defective en route after a Class I or IA brake test...passenger service that becomes defective en route after a Class I or IA brake test...brakes or any other power brake defect while en route to another location after...

2010-10-01

168

Effect of lateral run-out on calliper drag in automotive disc brakes  

Microsoft Academic Search

Efficiency of an automotive disc brake system is affected by several factors such as lateral run out (LRO), caliper housing stiffness, lining compressibility, seal\\/groove design, brake fluid, and pad material. A minor deviation in any of these factors may lead to problems like brake noise, vibration and off-brake caliper drag in the brake system. This paper presents an experimental study

S. H. Masood; Lakhwinder Singh

2007-01-01

169

Analysis Of The Friction Brake Lining Including Heat Transfer System And Thermal Analysis  

Microsoft Academic Search

Kinetic energy during braking of the moving mass is converted into heat energy through friction. This heat energy cause brake pads to be exposed to excessive temperature. The breaking efficiency reduces in time and in this case some problems (reducing in brake performance, defect run ning, rapid brake pad wear and noise) occur. Five different brake pad materials were subjected

Osman KOÇ

2009-01-01

170

Hibernation Revived by Weak Magnetic Braking  

E-print Network

Cataclysmic variables undergo periodic nova explosions during which a finite mass of material is expelled on a short timescale. The system widens and, as a result, the mass-transfer rate drops. This state of hibernation may account for the variety of cataclysmic variable types observed in systems of similar mass and period. In the light of recent changes to the theory of nova ignition and magnetic braking we investigate whether hibernation remains a viable mechanism for creating cataclysmic variable diversity. We model the ratio of time spent as dwarf novae (DNe) to nova-like systems (NLs). Above a critical mass-transfer rate the system is NL and below it a DN. The dominant loss of angular momentum is by magnetic braking but the rate is uncertain. It is also uncertain what fraction of the mass accreted is expelled during the novae. We compare the models of the ratios against the period of the system for different magnetic braking rates and different ejected masses with the ratio of the number of observed NLs to DNe. We deduce that a rate of angular momentum loss a factor of ten smaller than that traditionally assumed is necessary if hibernation is to account for the observed ratios.

Rebecca G. Martin; Christopher A. Tout

2006-09-07

171

Hibernation Revived by Weak Magnetic Braking  

E-print Network

Cataclysmic variables undergo periodic nova explosions during which a finite mass of material is expelled on a short timescale. The system widens and, as a result, the mass-transfer rate drops. This state of hibernation may account for the variety of cataclysmic variable types observed in systems of similar mass and period. In the light of recent changes to the theory of nova ignition and magnetic braking we investigate whether hibernation remains a viable mechanism for creating cataclysmic variable diversity. We model the ratio of time spent as dwarf novae (DNe) to nova-like systems (NLs). Above a critical mass-transfer rate the system is NL and below it a DN. The dominant loss of angular momentum is by magnetic braking but the rate is uncertain. It is also uncertain what fraction of the mass accreted is expelled during the novae. We compare the models of the ratios against the period of the system for different magnetic braking rates and different ejected masses with the ratio of the number of observed NLs ...

Martin, R G; Martin, Rebecca G.; Tout, Christopher A.

2005-01-01

172

Micromachined hydraulic astable multivibrator  

Microsoft Academic Search

1 Abstract The paper presents a hydraulic astable multivibrator system. The system consists of hydraulic resistors, hydraulic capacitors and hydraulic pressure controlled valves. The system is designed, realised and tested. The measured system behaviour agrees well with the model simulations. The free running frequency of the multivibrator is 0.18 Hz and the output pressure swing is 90% of the supply

T. S. J. Lammerink; N. R. Tas; J. W. Berenschot; M. C. Elwenspoek; J. H. J. Fluitman

1995-01-01

173

Design and Experimental Evaluation of a Magnetorheological Brake  

Microsoft Academic Search

A new magnetorheological (MR) brake prototype was designed, fabricated and tested. Firstly, the rheological properties of\\u000a MR fluids, in particular the dynamic yield stress, were experimentally investigated based on a Bingham plastic model. The\\u000a working principles of the MR brake were then analysed and discussed. The equations for transmitted torque were derived and\\u000a used to evaluate the disc-shaped MR brake.

W. H. Li; H. Du

2003-01-01

174

Tau as a Potential Control Variable for Visually Guided Braking  

ERIC Educational Resources Information Center

D. N. Lee (1976) described a braking strategy based on optical expansion in which the driver brakes so that the target's time-to-contact declines around a constant slope in the range -0.5 less than or equal to tau less than 0. The present results from a series of braking simulations confirm and extend earlier reports (E. H. Yilmaz & W. H. Warren,…

Rock, Paul B.; Harris, Mike G.

2006-01-01

175

Evaluation of Corrosion Failure in Tractor-Trailer Brake System  

Microsoft Academic Search

As reported to ORNL, concomitant with the introduction of different deicing and anti-icing compounds, there was an increase in the brake failure rate of tractor-trailer trucks. A forensic evaluation of a failed brake system was performed. Optical and scanning electron microscopic evaluation showed corrosion to be mostly confined to the brake table\\/lining interface. The corrosion is non-uniform as is to

2002-01-01

176

Antimony in brake pads-a carcinogenic component?  

Microsoft Academic Search

Antimony trisulfide (Sb2S3) is used as a lubricant in friction material. X-ray diffraction analysis revealed Sb in 3\\/3 disc brake pads (range 41,000–46,000 mg\\/kg) and in 2\\/2 disc brake dust samples (21,000 and 17,000 mg\\/kg) from trucks. Considerably lower concentrations were found in drum brake pads (3\\/5, 59–6400 mg\\/kg) and in drum brake dust (4\\/18, 78–2800 mg\\/kg). Other toxic metals

Ole von Uexküll; Staffan Skerfving; Reed Doyle; Michael Braungart

2005-01-01

177

Predicting the Braking Indices of Nulling and Intermittent Pulsars  

NASA Astrophysics Data System (ADS)

The braking index is an important factor when examining the pulsar braking mechanism. Measuring braking indices requires measuring the pulsar period and its first and second derivatives. Among them, the second derivative is easily contaminated by timing noise and an unresolved glitch effect. The absence of data bounding a given transition into (or out of) a radio-on phase is another disadvantage in measuring the second derivatives of intermittent pulsars, as was recently demonstrated by Young and coworkers. But, the observed period first derivatives, in the "on" and "off" states of the intermittent pulsars, give us a possible way to predict their braking indices even though they are hard to observe. In this paper, we will give a simple and useful method to study the braking indices of intermittent pulsars. As an application of our method, we will calculate the possible braking indices of three intermittent pulsars and one nulling pulsar, namely, PSR B1931 + 24, PSR J1841 - 0500, PSR J1832 + 0029 and PSR B0823 + 26, under three different magnetospheric conditions, which include polar cap size variation, charge density variation and the combination of the above two cases. We have found that all the braking indices we predicted are almost within the observed domain. It is concluded that, in a relatively short observation period, in which the variation of the braking index can be ignored, we can accurately predict the braking indices of intermittent pulsars, under a specific magnetosphere model, by using the observed "on" and "off" state period first derivatives.

Rusul, Abdujappar; Zheng, Xiao-Ping; Esamdin, Ali

2014-04-01

178

Evaluation of materials and design modifications for aircraft brakes  

NASA Technical Reports Server (NTRS)

A test program is described which was carried out to evaluate several proposed design modifications and several high-temperature friction materials for use in aircraft disk brakes. The evaluation program was carried out on a specially built test apparatus utilizing a disk brake and wheel half from a small het aircraft. The apparatus enabled control of brake pressure, velocity, and braking time. Tests were run under both constant and variable velocity conditions and covered a kinetic energy range similar to that encountered in aircraft brake service. The results of the design evaluation program showed that some improvement in brake performance can be realized by making design changes in the components of the brake containing friction material. The materials evaluation showed that two friction materials show potential for use in aircraft disk brakes. One of the materials is a nickel-based sintered composite, while the other is a molybdenum-based material. Both materials show much lower wear rates than conventional copper-based materials and are better able to withstand the high temperatures encountered during braking. Additional materials improvement is necessary since both materials show a significant negative slope of the friction-velocity curve at low velocities.

Ho, T. L.; Kennedy, F. E.; Peterson, M. B.

1975-01-01

179

75 FR 67634 - Parts and Accessories Necessary for Safe Operation: Antilock Brake Systems  

Federal Register 2010, 2011, 2012, 2013

...Necessary for Safe Operation: Antilock Brake Systems AGENCY: Federal Motor...Necessary for Safe Operation: Antilock Brake Systems,'' published on...Necessary for Safe Operation: Antilock Brake Systems'' in the...

2010-11-03

180

Design considerations for an automotive magnetorheological brake Kerem Karakoc, Edward J. Park *, Afzal Suleman  

E-print Network

Design considerations for an automotive magnetorheological brake Kerem Karakoc, Edward J. Park February 2008 Available online xxxx Keywords: Mechatronic design Magnetorheological fluid Automotive brake t In this paper, design considerations for building an automotive magnetorheological (MR) brake are dis- cussed

Park, Edward

181

49 CFR 236.554 - Rate of pressure reduction; equalizing reservoir or brake pipe.  

Code of Federal Regulations, 2013 CFR

... Rate of pressure reduction; equalizing reservoir or brake pipe. 236.554 Section 236... Rate of pressure reduction; equalizing reservoir or brake pipe. The equalizing-reservoir pressure or brake-pipe pressure...

2013-10-01

182

49 CFR 232.503 - Process to introduce new brake system technology.  

Code of Federal Regulations, 2010 CFR

...Process to introduce new brake system technology. 232.503 Section 232.503... Introduction of New Brake System Technology § 232.503 Process to introduce new brake system technology. (a) Pursuant to the...

2010-10-01

183

Measurement and control of brake pedal feel quality in automobile manufacturing  

E-print Network

Customer perception of brake pedal feel quality, as related to the perception of the brake pedal feeling soft or mushy, depends on both the customer's subjective judgment of quality and the actual build quality of the brake ...

Cerilles, Jeffrey T. (Jeffrey Thomas)

2005-01-01

184

49 CFR 232.503 - Process to introduce new brake system technology.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 false Process to introduce new brake system technology. 232.503 Section...END-OF-TRAIN DEVICES Introduction of New Brake System Technology § 232.503 Process to introduce new brake system technology. (a)...

2011-10-01

185

Metal-bending brake facilitates lightweight, close-tolerance fabrication  

NASA Technical Reports Server (NTRS)

A lightweight, metal bending brake ensures very accurate bends. Features of the brake that adapt it for making complex reverse bends to close tolerances are a pronounced relief or cutaway of the underside of the bodyplate combined with modification in the leaf design and its suspension.

Ercoline, A. L.; Wilton, K. B.

1964-01-01

186

Development of a multi-pole magnetorheological brake  

NASA Astrophysics Data System (ADS)

This paper presents a new approach in the design and optimization of a novel multi-pole magnetorheological (MR) brake that employs magnetic flux more effectively on the surface of the rotor. MR brakes with conventional single ring-type electromagnetic poles have reached the limits of torque enhancement. One major reason is the limitation of the magnetic field strength within the active area of the MR fluid due to the geometric constraints of the coil. The multi-pole MR brake design features multiple electromagnetic poles surrounded by several coils. As a result, the active chaining areas for the MR fluid are greatly increased, and significant brake torque improvement is achieved. The coil structure, as a part of the stator, becomes flexible and customizable in terms of space usage for the winding and bobbin design. In addition, this brake offers extra options in its dimensions for torque enhancement because either the radial or the axial dimensions of the rotor can be increased. Magnetic circuit analysis was conducted to analyze the effects of the design parameters on the field torque. After that, simulations were done to find the optimal design under all major geometric constraints with a given power supply. The results show that the multi-pole MR brake provides a considerable braking torque increase while maintaining a compact and solid design. This is confirmation of its feasibility in actual braking applications.

Shiao, Yaojung; Nguyen, Quang-Anh

2013-06-01

187

Field-circuit transient analysis of a magnetorheological fluid brake  

Microsoft Academic Search

This paper deals with coupled electromagnetic, hydrodynamic and mechanical motion phenomena in magnetorheological fluid brakes. The governing equations of these phenomena are presented. The numerical implementation of the mathematical model is based on the finite element method and a step-by-step algorithm. A computer program based on this algorithm was used to simulate the transients in a prototype of magnetorheological brake.

W. Szel?g; P. Sujka; R. Walendowski

2004-01-01

188

STABILITY ANALYSIS OF DISC BRAKE SQUEAL CONSIDERING TEMPERATURE EFFECT  

Microsoft Academic Search

Passenger cars have become one of the main transportations for people travelling from one place to another. Indeed, vehicle quietness and passenger comfort issues are a major concern. One of vehicle components that occasionally generate unwanted vibration and unpleasant noise is the brake system. Brake squeal noise is the most troublesome and irritant one to both car passenger and the

Abd Rahim; Abu Bakar; Mohd Kameil Abdul Hamid; Afandi Dzakaria; Badri Abdul Ghani; Maziah Mohamad

2006-01-01

189

Suppression of Brake Squeal Noise Applying Viscoelastic Damping Insulator  

Microsoft Academic Search

Squeal noise in vehicle disc brakes is perceived by consumers as both annoying and warranty cost. Among the methods that have been used to control squeal noise, increasing the system damping has been shown to be very effective. The most commonly used method to increase system damping consists of attaching multi-layer laminates on the back of the brake pads. As

Jun Hou; Xuexun Guo; Guohui Sun; Jie Zhang

2009-01-01

190

Surface modification of brake discs to reduce squeal problems  

Microsoft Academic Search

Noise and squeal from brakes is a problem in the automotive industry and large efforts are made to reduce the squeal tendencies. The approach taken is mainly to improve the design of the caliper, to fine-tune the brake pad material and finally to trim by introducing shims on the backside of the pads. Despite these efforts still no general solutions

Lars Hammerström; Staffan Jacobson

2006-01-01

191

Judder vibration in disc brakes excited by thermoelastic instability  

Microsoft Academic Search

Friction vibrations and noises which are common in brakes, have attracted a great deal of attention lately. This paper analyses low frequency vibrations in disc brakes excited at high car speed. This vibration, called judder, has a frequency in the range 10 to 300 Hz and usually comes in association with hum noises. The dynamic phenomenon shows two principal components,

Oscar Altuzarra; Enrique Amezua; Rafael Avilés; Alfonso Hernández

2002-01-01

192

Thermally induced roughness of tread braked railway wheels  

Microsoft Academic Search

Roughness (corrugation, waviness) on the tread of a rolling railway wheel leads to vibrations in wheels, bogies and superstructure and also in rails, sleepers and roadbed. These vibrating components radiate noise to the surroundings. A lowering of the noise levels from tread braked freight cars is of utmost importance for the future of rail traffic. The thermomechanical interaction between brake

T. Vernersson

1999-01-01

193

Thermally induced roughness of tread-braked railway wheels  

Microsoft Academic Search

Roughness (corrugation, waviness) on the tread of a rolling railway wheel leads to vibrations in wheels, bogies and superstructure and also in rails, sleepers and roadbed. These vibrating components radiate noise to the surroundings. A lowering of the noise levels from tread-braked freight cars is of utmost importance for the future of rail traffic. The thermomechanical interaction between brake block

T Vernersson

1999-01-01

194

49 CFR 393.41 - Parking brake system.  

Code of Federal Regulations, 2010 CFR

...holding the vehicle or combination of vehicles stationary...1975, and air-braked trailers manufactured on or after...bus, truck and truck tractor manufactured on and...and each air-braked trailer except an agricultural...holding the vehicle or combination of vehicles...

2010-10-01

195

How Things Work: Front and Rear Bicycle Brakes  

NSDL National Science Digital Library

This site from How Things Work, by Lou Bloomfield, provides an explanation of why it can be hard to stop a bike with the rear brakes alone. The site contains a description of how friction and torque produce a rotation of the bicycle that makes the rear brakes ineffective.

2006-11-08

196

Braking system for use with an arbor of a microscope  

DOEpatents

A balanced braking system comprising a plurality of braking assemblies located about a member to be braked. Each of the braking assemblies consists of a spring biased piston of a first material fitted into a body of a different material which has a greater contraction upon cooling than the piston material. The piston is provided with a recessed head portion over which is positioned a diaphragm and forming a space therebetween to which is connected a pressurized fluid supply. The diaphragm is controlled by the fluid in the space to contact or withdraw from the member to be braked. A cooling device causes the body within which the piston is fitted to contract more than the piston, producing a tight shrink fit therebetween. The braking system is particularly applicable for selectively braking an arbor of an electron microscope which immobilizes, for example, a vertically adjustable low temperature specimen holder during observation. The system provides balanced braking forces which can be easily removed and re-established with minimal disturbance to arbor location.

Norgren, Duane U. (Orinda, CA)

1984-01-01

197

A pressure control scheme for air brakes in commercial vehicles  

E-print Network

This research is focused on developing a control scheme for regulating the pressure in the brake chamber of an air brake system found in most commercial vehicles like trucks, tractor-trailers and buses. Such a control scheme can be used...

Bowlin, Christopher Leland

2007-04-25

198

Eigenvalue optimization against brake squeal: Symmetry, mathematical background and experiments  

NASA Astrophysics Data System (ADS)

Brake squeal is still a challenge for design engineers and scientists. Due to cost reasons for the avoidance of brake noise only passive measures are meaningful for a broad industrial range. Many countermeasures against squeal are based on the introduction of damping, for example by using shims. In the literature on the modeling of brake squeal, the structural properties of the brake disc are most often not considered. It has however been shown analytically and experimentally that the stiffness properties of the disc are important and that splitting of double modes of the disc has a stabilizing effect. This knowledge can be used for structural optimization of brake rotors. The goal of this paper is to exploit the potential and to discuss some mathematical difficulties. Furthermore, experimental evidence for the relation of rotor asymmetry and squeal is given.

Spelsberg-Korspeter, Gottfried

2012-09-01

199

Suppression of brake squeal noise applying finite element brake and pad model enhanced by spectral-based assurance criteria  

Microsoft Academic Search

An enhanced dynamic finite element (FE) model with friction coupling is applied to analyze the design of disc brake pad structure for squeal noise reduction. The FE model is built-up from the individual brake component representations. Its interfacial structural connections and boundary conditions are determined by correlating to a set of measured frequency response functions using a spectral-based assurance criterion.

Yi Dai; Teik C. Lim

2008-01-01

200

EEG potentials predict upcoming emergency brakings during simulated driving  

NASA Astrophysics Data System (ADS)

Emergency braking assistance has the potential to prevent a large number of car crashes. State-of-the-art systems operate in two stages. Basic safety measures are adopted once external sensors indicate a potential upcoming crash. If further activity at the brake pedal is detected, the system automatically performs emergency braking. Here, we present the results of a driving simulator study indicating that the driver's intention to perform emergency braking can be detected based on muscle activation and cerebral activity prior to the behavioural response. Identical levels of predictive accuracy were attained using electroencephalography (EEG), which worked more quickly than electromyography (EMG), and using EMG, which worked more quickly than pedal dynamics. A simulated assistance system using EEG and EMG was found to detect emergency brakings 130 ms earlier than a system relying only on pedal responses. At 100 km h-1 driving speed, this amounts to reducing the braking distance by 3.66 m. This result motivates a neuroergonomic approach to driving assistance. Our EEG analysis yielded a characteristic event-related potential signature that comprised components related to the sensory registration of a critical traffic situation, mental evaluation of the sensory percept and motor preparation. While all these components should occur often during normal driving, we conjecture that it is their characteristic spatio-temporal superposition in emergency braking situations that leads to the considerable prediction performance we observed.

Haufe, Stefan; Treder, Matthias S.; Gugler, Manfred F.; Sagebaum, Max; Curio, Gabriel; Blankertz, Benjamin

2011-10-01

201

A performance evaluation of an automotive magnetorheological brake design with a sliding mode controller  

E-print Network

A performance evaluation of an automotive magnetorheological brake design with a sliding mode Received 14 March 2006 Abstract The aim of this work is to develop a magnetorheological brake (MRB) system: Magnetorheological brake (MRB); Anti-lock brake system (ABS); Finite element analysis; Multidisciplinary design

Park, Edward

202

Process Optimization for the Improvement of Brake Noise: A Case Study  

Microsoft Academic Search

This study improves brake noise by optimizing the manufacturing processes of brake discs and pads. Taguchi techniques and designed experiments were used for the optimization. The signal-to-noise ratios of the key output responses, such as runouts of brake discs and compressibility of brake pads, were maximized to optimize the mean and variation. Analysis of the variance was performed to obtain

Hee Seong Sohn; Tae Won Park

2006-01-01

203

Numerical study on the vibration characteristics of automobile brake disk and pad  

Microsoft Academic Search

Based on the review of researches on the vibration and noise related to automobile brake, a four degrees of freedom nonlinear dynamics model of brake disk and pads is established, the stability of vibration system at the equilibrium points is analyzed. Finally the numerical method is taken to study the impacts of brake pressure, shape parameter and the brake disk's

Xianjie Meng; Guangqiang Wu; Lin He

2009-01-01

204

Side force coefficient estimation for the design of active brake control  

Microsoft Academic Search

In this paper an active brake control to reduce the rollover risk of heavy vehicles is proposed. The brake system is activated when the vehicle comes close to rolling over. In order to enhance the performance of the active brake, the braking algorithm is extended with an estimation procedure of the side force coefficient in order to use it in

Péter Gáspár; Zoltán Szabó; József Bokor

2006-01-01

205

49 CFR 393.47 - Brake actuators, slack adjusters, linings/pads and drums/rotors.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Brake actuators, slack adjusters, linings/pads and...OPERATION Brakes § 393.47 Brake actuators, slack adjusters, linings/pads and... (e) Clamp and roto-chamber brake actuator readjustment limits. The pushrod...

2011-10-01

206

49 CFR 393.47 - Brake actuators, slack adjusters, linings/pads and drums/rotors.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Brake actuators, slack adjusters, linings/pads and...OPERATION Brakes § 393.47 Brake actuators, slack adjusters, linings/pads and...bolt-type, and rotochamber brake actuator readjustment limits. (1) The...

2013-10-01

207

49 CFR 393.47 - Brake actuators, slack adjusters, linings/pads and drums/rotors.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false Brake actuators, slack adjusters, linings/pads and...OPERATION Brakes § 393.47 Brake actuators, slack adjusters, linings/pads and...bolt-type, and rotochamber brake actuator readjustment limits. (1) The...

2012-10-01

208

Hydraulics calculations for hydraulic Stirling engines  

SciTech Connect

The role of hydraulic devices and processes in Stirling engine design is discussed. Simple and conveniently organized algorithms are presented for the calculation of hydraulic system losses and for optimization of clearance seals. Fluid makeup system losses are discussed. The fluid inertia tube is compared with the free hydraulic piston. Scaling of power piston flow loss with engine design power level is such that flow loss inefficiencies tend to be large for engine power levels above a few hundred watts unless specific measures are taken to minimize the piston flow loss. A method for eliminating the power piston flow loss in large engines is discussed.

Riggle, P.; Emigh, S.G.; Lo, N.S.C.; Noble, J.E.; Olan, R.W.; White, M.A.

1984-08-01

209

A 6-DOF vibration isolation system for hydraulic hybrid vehicles  

NASA Astrophysics Data System (ADS)

This paper presents the results of vibration isolation analysis for the pump/motor component of hydraulic hybrid vehicles (HHVs). The HHVs are designed to combine gasoline/diesel engine and hydraulic power in order to improve the fuel efficiency and reduce the pollution. Electric hybrid technology is being applied to passenger cars with small and medium engines to improve the fuel economy. However, for heavy duty vehicles such as large SUVs, trucks, and buses, which require more power, the hydraulic hybridization is a more efficient choice. In function, the hydraulic hybrid subsystem improves the fuel efficiency of the vehicle by recovering some of the energy that is otherwise wasted in friction brakes. Since the operation of the main component of HHVs involves with rotating parts and moving fluid, noise and vibration are an issue that affects both passengers (ride comfort) as well as surrounding people (drive-by noise). This study looks into the possibility of reducing the transmitted noise and vibration from the hydraulic subsystem to the vehicle's chassis by using magnetorheological (MR) fluid mounts. To this end, the hydraulic subsystem is modeled as a six degree of freedom (6-DOF) rigid body. A 6-DOF isolation system, consisting of five mounts connected to the pump/motor at five different locations, is modeled and simulated. The mounts are designed by combining regular elastomer components with MR fluids. In the simulation, the real loading and working conditions of the hydraulic subsystem are considered and the effects of both shock and vibration are analyzed. The transmissibility of the isolation system is monitored in a wide range of frequencies. The geometry of the isolation system is considered in order to sustain the weight of the hydraulic system without affecting the design of the chassis and the effectiveness of the vibration isolating ability. The simulation results shows reduction in the transmitted vibration force for different working cycles of the regenerative system.

Nguyen, The; Elahinia, Mohammad; Olson, Walter W.; Fontaine, Paul

2006-03-01

210

Braking formula for electrons of relativistic speed  

NASA Astrophysics Data System (ADS)

The current translation is by Klaus Bartschat, Department of Physics and Astronomy, Drake University, Des Moines, Iowa 50311, USA. An attempt has been made to preserve Bethe's writing style as much as possible, including his use of "Volt" instead of "electron volt". Even though the term "stopping power" is quite common in present scientific English, we generally use "braking [capability]" rather than "stopping [power]", in order to emphasize the act [and ability] of slowing down the particle rather than the ultimate result of bringing it to a complete halt. Also, a few typographical errors were kept in the English translation to ensure the translation replicates the original paper. Please, see Section 3 of the annotation to Bethe's article [Fontes, C.J., Bostock, C.J. and Bartschat, K. 2014. Eur. Phys. J. H, 39: 517-536] for a list. The references were converted to EPJH style, and the footnotes are numbered consecutively.

Bethe, H.; Bartschat, Klaus

2014-12-01

211

2-DOF haptic device with DC motors and MR brakes  

NASA Astrophysics Data System (ADS)

This paper presents the 2-DOF haptic device in which DC motors and MR brakes are equipped. To apply MR brakes to the 2-DOF haptic device, its kinematic requirement is described by Jacobian analysis. Through the analysis, MR brakes can be used to display the damping force in a multi-DOF haptic device when it has the orthogonal Jacobian such as Cartesian manipulator. A five bar linkage type haptic device, which has the nonorthogonal Jacobian, is developed to verify the theoretical effort. Experimental results show that the five bar linkage type can't display the 2 DOF virtual environments due to its kinematic constraints, that is, nonorthogonal Jacobian.

An, Jinung; Kwon, Dong-Soo

2007-12-01

212

Behavior of aircraft antiskid braking systems on dry and wet runway surfaces: Hydromechanically controlled system  

NASA Technical Reports Server (NTRS)

The investigation utilized one main gear wheel, brake, and tire assembly of a McDonnell Douglas DC-9 series 10 airplane. The landing-gear strut was replaced by a dynamometer. During maximum braking, average braking behavior indexes based upon brake pressure, brake torque, and drag-force friction coefficient developed by the antiskid system were generally higher on dry surfaces than on wet surfaces. The three braking behavior indexes gave similar results but should not be used interchangeably as a measure of the braking of this antiskid sytem. During the transition from a dry to a flooded surface under heavy braking, the wheel entered into a deep skid but the antiskid system reacted quickly by reducing brake pressure and performed normally during the remainder of the run on the flooded surface. The brake-pressure recovery following transition from a flooded to a dry surface was shown to be a function of the antiskid modulating orifice.

Tanner, J. A.; Stubbs, S. M.; Smith, E. G.

1981-01-01

213

Metals associated with stormwater-relevant brake and tire samples  

PubMed Central

Properly apportioning the loads of metals in highway stormwater runoff to the appropriate sources requires accurate data on source composition, especially regarding constituents that help to distinguish among sources. Representative tire and brake samples were collected from privately owned vehicles and aqueous extracts were analyzed for twenty-eight elements. Correlation principal components analysis (PCA) revealed that tires were most influenced by Zn, Pb, and Cu, while brakes were best characterized by Na and Fe followed by Ba, Cu, Mg, Mn, and K; the latter three may be due to roadside soil contributions. Notably elevated Cd contributions were found in several brake samples. A targeted Cd-plated brake rotor was sampled, producing results consistent with the elevated levels found in the larger sample population. This enriched source of Cd is of particular concern due to high toxicity of Cd in aquatic ecosystems. PMID:19709720

McKenzie, Erica R.; Money, Jon E.; Green, Peter G.; Young, Thomas M.

2009-01-01

214

Evaluation strategy of regenerative braking energy for supercapacitor vehicle.  

PubMed

In order to improve the efficiency of energy conversion and increase the driving range of electric vehicles, the regenerative energy captured during braking process is stored in the energy storage devices and then will be re-used. Due to the high power density of supercapacitors, they are employed to withstand high current in the short time and essentially capture more regenerative energy. The measuring methods for regenerative energy should be investigated to estimate the energy conversion efficiency and performance of electric vehicles. Based on the analysis of the regenerative braking energy system of a supercapacitor vehicle, an evaluation system for energy recovery in the braking process is established using USB portable data-acquisition devices. Experiments under various braking conditions are carried out. The results verify the higher efficiency of energy regeneration system using supercapacitors and the effectiveness of the proposed measurement method. It is also demonstrated that the maximum regenerative energy conversion efficiency can reach to 88%. PMID:25311161

Zou, Zhongyue; Cao, Junyi; Cao, Binggang; Chen, Wen

2014-10-10

215

Implementation Of Fuzzy Automated Brake Controller Using TSK Algorithm  

NASA Astrophysics Data System (ADS)

In this paper an application of Fuzzy Logic for Automatic Braking system is proposed. Anti-blocking system (ABS) brake controllers pose unique challenges to the designer: a) For optimal performance, the controller must operate at an unstable equilibrium point, b) Depending on road conditions, the maximum braking torque may vary over a wide range, c) The tire slippage measurement signal, crucial for controller performance, is both highly uncertain and noisy. A digital controller design was chosen which combines a fuzzy logic element and a decision logic network. The controller identifies the current road condition and generates a command braking pressure signal Depending upon the speed and distance of train. This paper describes design criteria, and the decision and rule structure of the control system. The simulation results present the system's performance depending upon the varying speed and distance of the train.

Mittal, Ruchi; Kaur, Magandeep

2010-11-01

216

49 CFR 393.55 - Antilock brake systems.  

Code of Federal Regulations, 2010 CFR

...Air brake systems. (1) Each truck tractor manufactured on or after March 1, 1997 (except truck tractors engaged in driveaway-towaway operations...commercial motor vehicle other than a truck tractor, manufactured on or after March...

2010-10-01

217

49 CFR 232.215 - Transfer train brake tests.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Transfer train brake tests. 232.215 Section 232.215...STANDARDS FOR FREIGHT AND OTHER NON-PASSENGER TRAINS AND EQUIPMENT; END-OF-TRAIN DEVICES Inspection and Testing Requirements...

2011-10-01

218

49 CFR 232.215 - Transfer train brake tests.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false Transfer train brake tests. 232.215 Section 232.215...STANDARDS FOR FREIGHT AND OTHER NON-PASSENGER TRAINS AND EQUIPMENT; END-OF-TRAIN DEVICES Inspection and Testing Requirements...

2012-10-01

219

49 CFR 232.215 - Transfer train brake tests.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Transfer train brake tests. 232.215 Section 232.215...STANDARDS FOR FREIGHT AND OTHER NON-PASSENGER TRAINS AND EQUIPMENT; END-OF-TRAIN DEVICES Inspection and Testing Requirements...

2013-10-01

220

49 CFR 232.215 - Transfer train brake tests.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 false Transfer train brake tests. 232.215 Section 232.215...STANDARDS FOR FREIGHT AND OTHER NON-PASSENGER TRAINS AND EQUIPMENT; END-OF-TRAIN DEVICES Inspection and Testing Requirements...

2010-10-01

221

Modeling of air brakes for onboard diagnostics of heavy trucks  

E-print Network

and handling performance thereby increasing the potential for fatal accidents. As a result, there is a need for the advanced diagnostic system that monitors the health of air brakes and thus aiding in preventing the accidents. Therefore, the research...

Kankanala, Penchala N

2000-01-01

222

17. VIEW SOUTHEAST, REDUCTION GEARING AND MOTOR (WITH SOLENOID BRAKE) ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

17. VIEW SOUTHEAST, REDUCTION GEARING AND MOTOR (WITH SOLENOID BRAKE) FOR END LOCKS; VERTICAL SHAFT IN CENTER FOR MANUAL OPERATION - Grand Street Bridge, Spanning Pequonnock River at Grand Street, Bridgeport, Fairfield County, CT

223

22. General view inside air brake shop section of roundhouse. ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

22. General view inside air brake shop section of roundhouse. View to west. - Duluth & Iron Range Rail Road Company Shops, Roundhouse, Southwest of downtown Two Harbors, northwest of Agate Bay, Two Harbors, Lake County, MN

224

Stability analysis and \\mu-synthesis control of brake systems  

E-print Network

The concept of friction-induced brake vibrations, commonly known as judder, is investigated. Judder vibration is based on the class of geometrically induced or kinematic constraint instability. After presenting the modal coupling mechanism and the associated dynamic model, a stability analysis as well as a sensitivity analysis have been conducted in order to identify physical parameters for a brake design avoiding friction-induced judder instability. Next, in order to reduce the size of the instability regions in relation to possible system parameter combinations, robust stability via \\mu-synthesis is applied. By comparing the unstable regions between the initial and controlled brake system, some general indications emerge and it appears that robust stability via \\mu-synthesis has some effect on the instability of the brake system.

Lignon, Sylvain; Jezequel, Louis

2008-01-01

225

Investigation of aerodynamic braking devices for wind turbine applications  

SciTech Connect

This report documents the selection and preliminary design of a new aerodynamic braking system for use on the stall-regulated AWT-26/27 wind turbines. The goal was to identify and design a configuration that offered improvements over the existing tip brake used by Advanced Wind Turbines, Inc. (AWT). Although the design objectives and approach of this report are specific to aerodynamic braking of AWT-26/27 turbines, many of the issues addressed in this work are applicable to a wider class of turbines. The performance trends and design choices presented in this report should be of general use to wind turbine designers who are considering alternative aerodynamic braking methods. A literature search was combined with preliminary work on device sizing, loads and mechanical design. Candidate configurations were assessed on their potential for benefits in the areas of cost, weight, aerodynamic noise, reliability and performance under icing conditions. As a result, two configurations were identified for further study: the {open_quotes}spoiler-flap{close_quotes} and the {open_quotes}flip-tip.{close_quotes} Wind tunnel experiments were conducted at Wichita State University to evaluate the performance of the candidate aerodynamic brakes on an airfoil section representative of the AWT-26/27 blades. The wind tunnel data were used to predict the braking effectiveness and deployment characteristics of the candidate devices for a wide range of design parameters. The evaluation was iterative, with mechanical design and structural analysis being conducted in parallel with the braking performance studies. The preliminary estimate of the spoiler-flap system cost was $150 less than the production AWT-26/27 tip vanes. This represents a reduction of approximately 5 % in the cost of the aerodynamic braking system. In view of the preliminary nature of the design, it would be prudent to plan for contingencies in both cost and weight.

Griffin, D.A. [R. Lynette & Associates, Seattle, WA (United States)

1997-04-01

226

Gain-scheduled wheel slip control in automotive brake systems  

Microsoft Academic Search

A wheel slip controller is developed and experimentally tested in a car equipped with electromechanical brake actuators and a brake-by-wire system. A gain scheduling approach is taken, where the vehicle speed is viewed as a slowly time-varying parameter and the model is linearized about the nominal wheel slip. Gain matrices for the different operating conditions are designed using an LQR

Tor A. Johansen; Idar Petersen; Jens Kalkkuhl; Jens Ludemann

2003-01-01

227

Numerical Analysis of Car Disc Brake Squeal Considering Thermal Effects  

Microsoft Academic Search

Friction-induced vibration and noise emanating from car disc brakes is a source of considerable discomfort and leads to customer\\u000a dissatisfaction. The high frequency noise above 1 kHz, known as squeal, is most annoying and is very difficult to eliminate.\\u000a It was recently estimated that noise, harshness and vibration (together known as the NVH problem), including disc brake squeal,\\u000a generated warranty

Lijie Li; Huajiang Ouyang; A. R. AbuBakar

228

The T.G.V. disk brake squeal  

Microsoft Academic Search

Discomfort problems due to the noise emittence of braking systems in trains have suggested recently several mechanical analyses.\\u000a This paper gives some of our results obtained from the numerical modelling of TGV brakes in relation with some experimental\\u000a data. The numerical discussion is based upon the Coulomb’s law of contact with a constant coefficient of friction. A dynamic\\u000a stability analysis

X. Lorang; Q. S. Nguyen; F. Margiocchi; P. E. Gautier

229

How Drivers Respond to Alarms Adapted to Their Braking Behaviour?  

NASA Astrophysics Data System (ADS)

Determining appropriate alarm timing for Forward Collision Warning Systems (FCWS) may play an important role in enhancing system acceptance by drivers. It is not always true that a common alarm trigger logic is suitable for all drivers, because presented alarms may be differently viewed for each driver, i.e., paying attention or requiring appropriate actions. The current study focused on adaptive alarm timing which was adjusted in response to braking behaviour for collision avoidance for the individual. In Experiment I, the braking performance of individual driver was measured repeatedly to assess the variation of each performance. We utilised the following two indices: elapsed time from the deceleration of the lead car to release of the accelerator (accelerator release time) and elapsed time to application of the brakes (braking response time). Two alarm timings were then determined based on these two indices: (i) the median of the accelerator release time of the driver and (ii) the median of the braking response time of the driver. Experiment II compared the two alarm timings for each driver in order to investigate which timing is more appropriate for enhancing driver trust in the driver-adaptive FCWS and the system effectiveness. The results showed that the timing of the accelerator release time increased the trust ratings more than the timing of braking response. The timing of the braking response time induced a longer response time to application of the brakes. Moreover, the degree to which the response time was longer depended on alarm timing preference of the driver. The possible benefit and drawback of driver-adaptive alarm timing are discussed.

Abe, Genya; Itoh, Makoto

230

Research study on antiskid braking systems for the space shuttle  

NASA Technical Reports Server (NTRS)

A research project to investigate antiskid braking systems for the space shuttle vehicle was conducted. System from the Concorde, Boeing 747, Boeing 737, and Lockheed L-1011 were investigated. The characteristics of the Boeing 737 system which caused it to be selected are described. Other subjects which were investigated are: (1) trade studies of brake control concepts, (2) redundancy requirements trade study, (3) laboratory evaluation of antiskid systems, and (4) space shuttle hardware criteria.

Auselmi, J. A.; Weinberg, L. W.; Yurczyk, R. F.; Nelson, W. G.

1973-01-01

231

Asbestos-free brake-lining materials for hydrogenerators  

SciTech Connect

Three different asbestos-free materials currently considered as new lining materials for hydrogenerator brakes were tested and compared to the original asbestos lining. Results show that these substitutes not only vary greatly from the original material in terms of mechanical properties and physical characteristics but also exhibit significantly different performances in braking tests. Consequently, these new materials are not entirely suitable for the intended application.

Lalonde, S.; Lanteigne, J. [Hydro-Quebec, Varennes, Quebec (Canada)

1995-11-01

232

6. North wall and east end of air brake shop ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

6. North wall and east end of air brake shop section of roundhouse at center. East end of boiler shop section of roundhouse to the right of air brake shop. East end of blacksmith shop section of roundhouse at far right. View to southeast. - Duluth & Iron Range Rail Road Company Shops, Roundhouse, Southwest of downtown Two Harbors, northwest of Agate Bay, Two Harbors, Lake County, MN

233

The application of hydraulics in the 2,000 kW wind turbine generator  

NASA Technical Reports Server (NTRS)

A 2000 kW turbine generator using hydraulic power in two of its control systems is being built under the management of NASA Lewis Research Center. The hydraulic systems providing the control torques and forces for the yaw and blade pitch control systems are discussed. The yaw-drive-system hydraulic supply provides the power for positioning the nacelle so that the rotary axis is kept in line with the direction of the prevailing wind, as well as pressure to the yaw and high speed shaft brakes. The pitch-change-mechanism hydraulic system provides the actuation to the pitch change mechanism and permits feathering of the blades during an emergency situation. It operates in conjunction with the overall windmill computer system, with the feather control permitting slewing control flow to pass from the servo valve to the actuators without restriction.

Onufreiczuk, S.

1978-01-01

234

Infrared characterization of thermal gradients on disc brakes  

NASA Astrophysics Data System (ADS)

The heat generated in frictional organs like brakes and clutches induces thermal distortions which may lead to localized contact areas and hot spots developments. Hot spots are high thermal gradients on the rubbing surface. They count among the most dangerous phenomena in frictional organs leading to damage, early failure and unacceptable braking performances such as brake fade or undesirable low frequency vibrations called hot judder. In this paper, an experimental study of hot spots occurrence in railway disc brakes is reported on. The aim of this study was to better classify and to explain the thermal gradients appearance on the surface of the disc. Thermograph measurements with an infrared camera have been carried out on the rubbing surface of brake discs on a full-scale test bench. The infrared system was set to take temperature readings in snap shot mode precisely synchronized with the rotation of the disc. Very short integration time allows reducing drastically haziness of thermal images. Based on thermographs, a classification of hot-spots observed in disc brakes is proposed. A detailed investigation of the most damaging thermal gradients, called macroscopic hot spots (MHS) is given. From these experimental researches, a scenario of hot spots occurrence is suggested step by step. Thanks to infrared measurements at high frequency with high resolution, observations give new highlights on the conditions of hot spots appearance. Comparison of the experimental observations with the theoretical approaches is finally discussed.

Panier, Stephane; Dufrenoy, Philippe; Bremond, Pierre

2003-04-01

235

Hard Braking Events Among Novice Teenage Drivers By Passenger Characteristics.  

PubMed

In a naturalistic study of teenage drivers (N = 42) hard braking events of ?-0.45 g were assessed over the first 6 months of licensure. A total of 1,721 hard braking events were recorded. The video footage of a sample (816) of these events was examined to evaluate validity and reasons for hard braking. Of these, 788 (96.6%) were estimated valid, of which 79.1% were due to driver misjudgment, 10.8% to risky driving behavior, 5.3% to legitimate evasive maneuvers, and 4.8% to distraction. Hard braking events per 10 trips and per 100 miles were compared across passenger characteristics. Hard braking rates per 10 trips among newly licensed teenagers during the first 6 months of licensure were significantly higher when driving with teen passengers and lower with adult passengers than driving alone; rates per 100 miles were lower with adult passengers than with no passengers. Further examination of the results indicates that rates of hard braking with teenage passengers were significantly higher compared with no passengers: 1) for male drivers; 2) during the first month of licensure. The data suggest that that novice teenage driving performance may not be as good or safe when driving alone or with teenage passengers than with adult passengers and provide support for the hypothesis that teenage passengers increase driving risks, particularly during the first month of licensure. PMID:21243109

Simons-Morton, Bruce G; Ouimet, Marie Claude; Wang, Jing; Klauer, Sheila G; Lee, Suzanne E; Dingus, Thomas A

2009-06-22

236

Hard Braking Events Among Novice Teenage Drivers By Passenger Characteristics  

PubMed Central

Summary In a naturalistic study of teenage drivers (N = 42) hard braking events of ??0.45 g were assessed over the first 6 months of licensure. A total of 1,721 hard braking events were recorded. The video footage of a sample (816) of these events was examined to evaluate validity and reasons for hard braking. Of these, 788 (96.6%) were estimated valid, of which 79.1% were due to driver misjudgment, 10.8% to risky driving behavior, 5.3% to legitimate evasive maneuvers, and 4.8% to distraction. Hard braking events per 10 trips and per 100 miles were compared across passenger characteristics. Hard braking rates per 10 trips among newly licensed teenagers during the first 6 months of licensure were significantly higher when driving with teen passengers and lower with adult passengers than driving alone; rates per 100 miles were lower with adult passengers than with no passengers. Further examination of the results indicates that rates of hard braking with teenage passengers were significantly higher compared with no passengers: 1) for male drivers; 2) during the first month of licensure. The data suggest that that novice teenage driving performance may not be as good or safe when driving alone or with teenage passengers than with adult passengers and provide support for the hypothesis that teenage passengers increase driving risks, particularly during the first month of licensure. PMID:21243109

Simons-Morton, Bruce G.; Ouimet, Marie Claude; Wang, Jing; Klauer, Sheila G.; Lee, Suzanne E.; Dingus, Thomas A.

2010-01-01

237

Braking and cornering studies on an air cushion landing system  

NASA Technical Reports Server (NTRS)

An experimental investigation was conducted to evaluate several concepts for braking and steering a vehicle equipped with an air cushion landing system (ACLS). The investigation made use of a modified airboat equipped with an ACLS. Braking concepts were characterized by the average deceleration of the vehicle. Reduced lobe flow and cavity venting braking concepts were evaluated in this program. The cavity venting braking concept demonstrated the best performance, producing decelerations on the test vehicle on the same order as moderate braking with conventional wheel brakes. Steering concepts were evaluated by recording the path taken while attempting to follow a prescribed maneuver. The steering concepts evaluated included using rudders only, using differential lobe flow, and using rudders combined with a lightly loaded, nonsteering center wheel. The latter concept proved to be the most accurate means of steering the vehicle on the ACLS, producing translational deviations two to three times higher than those from conventional nose-gear steering. However, this concept was still felt to provide reasonably precise steering control for the ACLS-equipped vehicle.

Daugherty, R. H.

1983-01-01

238

Hall drift and the braking indices of young pulsars  

NASA Astrophysics Data System (ADS)

Braking index measurements of young radio pulsars are all smaller than the value expected for spin-down by magnetic dipole braking. We investigate magnetic field evolution in the neutron star crust due to Hall drift as an explanation for observed braking indices. Using numerical simulations and a semi-analytic model, we show that an ?1014 G quadrupolar toroidal field in the neutron star crust at birth leads to growth of the dipole moment at a rate large enough to agree with measured braking indices. A key factor is the density at which the crust yields to magnetic stresses that build up during the evolution, which sets a characteristic minimum Hall time-scale. The observed braking indices of pulsars with inferred dipole fields of ? 1013 G can be explained in this picture, although with a significant octupole component needed in some cases. For the stronger field pulsars, those with Bd ? 1013 G, we find that the magnetic stresses in the crust exceed the maximum shear stress before the pulsar reaches its current age, likely quenching the Hall effect. This may have implications for the magnetar activity seen in the high magnetic field radio pulsar PSR J1846-0258. Observations of braking indices may therefore be a new piece of evidence that neutron stars contain subsurface toroidal fields that are significantly stronger than the dipole field, and may indicate that the Hall effect is important in a wider range of neutron stars than previously thought.

Gourgouliatos, K. N.; Cumming, A.

2015-01-01

239

Nonlinear control design for implementation of specific pedal feeling in brake-by-wire car design concepts  

Microsoft Academic Search

Brake-by-wire means that the direct mechanical link between brake pedal and braking cylinder is completely replaced by an electromechanical braking system. This concept, originally used for aircraft and military only, has massive advantages for implementing in new car designs. As a consequence, the pedal movement can be generated arbitrarily. Ideally, the pedal could behave like a conventional brake. In the

A. Hildebrandt; O. Sawodny; R. Trutschel; K. Augsburg

2004-01-01

240

Thermally Actuated Hydraulic Pumps  

NASA Technical Reports Server (NTRS)

Thermally actuated hydraulic pumps have been proposed for diverse applications in which direct electrical or mechanical actuation is undesirable and the relative slowness of thermal actuation can be tolerated. The proposed pumps would not contain any sliding (wearing) parts in their compressors and, hence, could have long operational lifetimes. The basic principle of a pump according to the proposal is to utilize the thermal expansion and contraction of a wax or other phase-change material in contact with a hydraulic fluid in a rigid chamber. Heating the chamber and its contents from below to above the melting temperature of the phase-change material would cause the material to expand significantly, thus causing a substantial increase in hydraulic pressure and/or a substantial displacement of hydraulic fluid out of the chamber. Similarly, cooling the chamber and its contents from above to below the melting temperature of the phase-change material would cause the material to contract significantly, thus causing a substantial decrease in hydraulic pressure and/or a substantial displacement of hydraulic fluid into the chamber. The displacement of the hydraulic fluid could be used to drive a piston. The figure illustrates a simple example of a hydraulic jack driven by a thermally actuated hydraulic pump. The pump chamber would be a cylinder containing encapsulated wax pellets and containing radial fins to facilitate transfer of heat to and from the wax. The plastic encapsulation would serve as an oil/wax barrier and the remaining interior space could be filled with hydraulic oil. A filter would retain the encapsulated wax particles in the pump chamber while allowing the hydraulic oil to flow into and out of the chamber. In one important class of potential applications, thermally actuated hydraulic pumps, exploiting vertical ocean temperature gradients for heating and cooling as needed, would be used to vary hydraulic pressures to control buoyancy in undersea research vessels. Heretofore, electrically actuated hydraulic pumps have been used for this purpose. By eliminating the demand for electrical energy for pumping, the use of the thermally actuated hydraulic pumps could prolong the intervals between battery charges, thus making it possible to greatly increase the durations of undersea exploratory missions.

Jones, Jack; Ross, Ronald; Chao, Yi

2008-01-01

241

Intelligently Controllable Walker with Magnetorheological Fluid Brake  

NASA Astrophysics Data System (ADS)

Caster walkers are supporting frames with casters and wheels. These tools are regularly utilized as life support tools or walking rehabilitation tools in hospitals, nursing homes and individual residences. Users of the walkers can easily move it thanks to its wheels and casters. However falling accidents often happen when it moves without users. The falling accident is very serious problem and one of leading causes of secondary injuries. In the other case, it is hard to move to desired directions if users have imbalance in their motor functions or sensory functions, e.g., hemiplegic patients. To improve safeness and operability of the walkers, we installed compact MR fluid brakes on the wheels and controlled walking speed and direction of the walker. We named this intelligently controllable walker, “i-Walker” and discussed on the control methods and experimental results in this paper. Preliminary trials for direction control of the first-generation of the i-Walker (i-Walker1) are presented. On the basis of the results, we improved the control method and hardware of the i-Walker1, and developed the second-generation (i-Walker2). System description and experimental results of the i-Walker2 are also described. The i-Walker2 has better operability and lower energy consumption than that of the i-Walker1. The line-tracing controller of the i-Walker2 well controls human motions during walking experiments on the target straight line.

Kikuchi, Takehito; Tanida, Sosuke; Tanaka, Toshimasa; Kobayashi, Keigo; Mitobe, Kazuhisa

242

Leaf Hydraulics Lawren Sack1  

E-print Network

Leaf Hydraulics Lawren Sack1 and N. Michele Holbrook2 1 Department of Botany, University of Hawai influence rates of transpiration and photosynthesis. Leaf hydraulic conductance (Kleaf) varies more than 65. #12;Contents INTRODUCTION. . . . . . . . . . . . . . . . . 362 LEAF HYDRAULIC CONDUCTANCE

Sack, Lawren

243

Suspensions in hydraulic fracturing  

Microsoft Academic Search

Suspensions or slurries are widely used in well stimulation and hydraulic fracturing processes to enhance the production of oil and gas from the underground hydrocarbon-bearing formation. The success of these processes depends significantly upon having a thorough understanding of the behavior of suspensions used. Therefore, the characterization of suspensions under realistic conditions, for their rheological and hydraulic properties, is very

Shah

1996-01-01

244

Experimental analysis of brake squeal noise on a laboratory brake setup  

NASA Astrophysics Data System (ADS)

The present paper is the first of two papers dealing with brake squeal instability. An experimental setup is specifically designed for this purpose and is characterized by a simple design to aid measurements and modeling. This first paper describes the experimental setup called "laboratory brake" and presents the measurements performed on it to characterize its dynamical behavior and its squeal behavior. The tests are aimed at identifying the key parameters controlling the squeal phenomenon that are necessary to build a model of the setup. The experimental analysis on squeal presented here identifies several characteristics that lead to instabilities and correlates them with the operating parameters as well as with the dynamic behavior of the system. Measurements also highlight that the pad dynamics have a key role in the selection of the squealing modes at one of the out-of-plane eigenfrequency of the system. Finally, the experimental results provide a better understanding of the physics of the squeal mechanism and suggest guidelines to build a representative model of the setup.

Giannini, Oliviero; Akay, Adnan; Massi, Francesco

2006-04-01

245

Downhole hydraulic seismic generator  

DOEpatents

A downhole hydraulic seismic generator system for transmitting energy wave vibrations into earth strata surrounding a borehole. The system contains an elongated, unitary housing operably connected to a well head aboveground by support and electrical cabling, and contains clamping apparatus for selectively clamping the housing to the walls of the borehole. The system further comprises a hydraulic oscillator containing a double-actuating piston whose movement is controlled by an electro-servovalve regulating a high pressure hydraulic fluid flow into and out of upper and lower chambers surrounding the piston. The spent hydraulic fluid from the hydraulic oscillator is stored and pumped back into the system to provide high pressure fluid for conducting another run at the same, or a different location within the borehole.

Gregory, Danny L. (Corrales, NM); Hardee, Harry C. (Albuquerque, NM); Smallwood, David O. (Albuquerque, NM)

1992-01-01

246

Development of a multilayered wide-ranged torque magnetorheological brake  

NASA Astrophysics Data System (ADS)

This paper presents the design of a multilayered magnetorheological brake from modelling to prototyping and characterization. A magnetostatic model intended to provide a specific magnetic flux density over a fluid gap regardless of the dimensions of the fluid surface is proposed. The ferromagnetic path and the coil are dimensioned in consequence. The model needs only three inputs to completely define the brake, i.e. the number of fluid gaps, the inner radius of the smallest fluid gap and the fluid gap depth. The evaluation criteria are defined by the torque density, the controllability and the reactivity, described as a function of the dimensions and the number of fluid gaps. The model has been optimized to improve the torque density. The brake has four fluid gaps and has been built and characterized. The expected torque when the fluid reaches the desired induction is 3.4 N m and the measured torque is 3.6 N m. This represents a relative error of 5.5%. The brake has 60 mm diameter, 39 mm width with a hollow shaft of 12 mm diameter. When exploited up to complete saturation, the measured torque is 5.3 N m with 19 W power consumption. The brake has a torque density of 48.1 kN m-2 and a maximum-to-minimum torque ratio of 176, with 50 ms electromechanical time constant.

Rossa, Carlos; Jaegy, Adrien; Micaelli, Alain; Lozada, José

2014-02-01

247

Thermophysical Properties of Automotive Metallic Brake Disk Materials  

NASA Astrophysics Data System (ADS)

The temperature distribution, the thermal deformation, and the thermal stress of automotive brake disks have quite close relations with car safety; therefore, much research in this field has been performed. However, successful and satisfactory results have not been obtained because the temperature-dependent thermophysical properties of brake disk materials are not sufficiently known. In this study, the thermophysical properties (thermal diffusivity, the specific heat, and the coefficient of thermal expansion) of three kinds of iron alloy series brake disk materials, FC250, FC170, and FCD50, and two kinds of aluminum alloy series brake disk materials, Al MMC and A356, were measured in the temperature range from room temperature to 500 °C, and the thermal conductivity was calculated using the measured thermal diffusivity, specific heat capacity, and density. As expected, the results show that the two series have significant differences in respect of the thermophysical properties, and to reduce the thermal deformation of the brake disk, the aluminum alloys with a high thermal conductivity and the iron alloys with low thermal expansion are recommended.

Kim, S. W.; Park, K.; Lee, S. H.; Kang, K. H.; Lim, K. T.

2008-12-01

248

Speed Gradient Approach to Longitudinal Control of Heavy-Duty Vehicles Equipped with Variable Compression Brake  

E-print Network

Speed Gradient Approach to Longitudinal Control of Heavy-Duty Vehicles Equipped with Variable Barbara Abstract Speed regulation of Heavy-Duty Vehicles equipped with variable compression brake- ging" the service brakes exemplifies these limitations (Fitch, 1994). Operational speeds comperable

Stefanopoulou, Anna

249

49 CFR 232.209 - Class II brake tests-intermediate inspection.  

Code of Federal Regulations, 2012 CFR

...and requirements: (1) Brake pipe leakage shall not exceed 5 psi per minute, or air flow shall not exceed 60 cubic feet per minute (CFM). The brake pipe leakage test or air flow method test shall be conducted...

2012-10-01

250

49 CFR 232.209 - Class II brake tests-intermediate inspection.  

Code of Federal Regulations, 2013 CFR

...and requirements: (1) Brake pipe leakage shall not exceed 5 psi per minute, or air flow shall not exceed 60 cubic feet per minute (CFM). The brake pipe leakage test or air flow method test shall be conducted...

2013-10-01

251

49 CFR 232.209 - Class II brake tests-intermediate inspection.  

Code of Federal Regulations, 2011 CFR

...and requirements: (1) Brake pipe leakage shall not exceed 5 psi per minute, or air flow shall not exceed 60 cubic feet per minute (CFM). The brake pipe leakage test or air flow method test shall be conducted...

2011-10-01

252

Regenerative braking device with rotationally mounted energy storage means  

DOEpatents

A regenerative braking device for an automotive vehicle includes an energy storage assembly (12) having a plurality of rubber rollers (26, 28) mounted for rotation between an input shaft (30) and an output shaft (32), clutches (50, 56) and brakes (52, 58) associated with each shaft, and a continuously variable transmission (22) connectable to a vehicle drivetrain and to the input and output shafts by the respective clutches. In a second embodiment the clutches and brakes are dispensed with and the variable ratio transmission is connected directly across the input and output shafts. In both embodiments the rubber rollers are torsionally stressed to accumulate energy from the vehicle when the input shaft rotates faster or relative to the output shaft and are torsionally relaxed to deliver energy to the vehicle when the output shaft rotates faster or relative to the input shaft.

Hoppie, Lyle O. (Birmingham, MI)

1982-03-16

253

Characterization of the high-frequency squeal on a laboratory brake setup  

Microsoft Academic Search

This paper presents an experimental investigation on high-frequency brake squeal noise conducted on an appropriately designed experimental rig, called laboratory brake.Brake squeal is one of the major issues in the design process of an automotive brake and the development of a robust procedure for a “squeal-free” design is still under investigation. The high-frequency squeal is the most frequent noise generated

Oliviero Giannini; Francesco Massi

2008-01-01

254

Study on Reliability Test for Brake Control Execution Unit of Rail Transit Vehicle  

Microsoft Academic Search

The brake system is the safety-critical subsystem of rail transit vehicle. However, the reliability test technology related to rail transportation equipments is much needed in China. In this paper, a certain Chinese computer-controlled electro-pneumatic brake system was selected to conduct reliability analysis by FMEA and BCEU (Brake Control Execution Unit) was determined the weak link of the brake system. Then,

Luo Min; Wu Meng-lin; Wang Xiao-yan

2010-01-01

255

Evaluation of Corrosion Failure in Tractor-Trailer Brake System  

SciTech Connect

As reported to ORNL, concomitant with the introduction of different deicing and anti-icing compounds, there was an increase in the brake failure rate of tractor-trailer trucks. A forensic evaluation of a failed brake system was performed. Optical and scanning electron microscopic evaluation showed corrosion to be mostly confined to the brake table/lining interface. The corrosion is non-uniform as is to be expected for plain carbon steel in chloride environments. This initial analysis found no evidence for the chlorides of calcium and magnesium, which are the newly introduced deicing and antiicing compounds and are less soluble in water than the identified chlorides of sodium and potassium, in the scale. The result could be as a result of non-exposure of the examined brake table to calcium and magnesium chloride. The mechanisms for the increased failure rate are postulated as being an increased rate of corrosion due to positive shifts in the corrosion potential, and an increased amount of corrosion due to an increased ''time of wetness'' that results from the presence of hygroscopic salts. Laboratory scale evaluation of the corrosion of plain carbon steel in simulated deicing and anti-icing solutions need to be performed to determine corrosion rates and morphological development of corrosion product, to compare laboratory data to in-service data, and to rank economically feasible replacement materials for low carbon steel. In addition, the mechanical behavior of the lining attached to the brake shoe table needs to be assessed. It is opined that an appropriate adjustment of materials could easily allow for a doubling of a brake table/lining lifetime. Suggestions for additional work, to clarify the mechanisms of rust jacking and to develop possible solutions, are described.

Wilson, DF

2002-10-22

256

Disc brake squeal characterization through simplified test rigs  

NASA Astrophysics Data System (ADS)

This paper presents a review of recent investigations on brake squeal noise carried out on simplified experimental rigs. The common theme of these works is that of approaching the study of squeal noise on experimental set-ups that are much simpler than commercial disc brakes, providing the possibility of repeatable measurements of squeal occurrence. As a consequence, it is possible to build consistent and robust models of the experimental apparatus to simulate the squeal events and to understand the physics behind squeal instabilities.

Akay, A.; Giannini, O.; Massi, F.; Sestieri, A.

2009-11-01

257

Hydraulic Fracturing Sand  

USGS Multimedia Gallery

Fine-grained silica sand is mixed with chemicals and water before being pumped into rock formations to prevent the newly created artificial fractures from closing after hydraulic fracturing is completed....

258

A Series Regenerative Braking Control Strategy Based on Hybrid-Power  

Microsoft Academic Search

A regenerative braking system, which could restore kinetic energy and potential energy to a battery or any other forms of power during braking, is a special system for electric and hybrid electric vehicles. However, the large current produced by the generator during braking would affect battery performance and shorten battery life. A hybrid-power system is an excellent energy storage system,

Feng Wang; Xiaomei Yin; Huangqiang Luo; Ying Huang

2012-01-01

259

49 CFR 232.309 - Equipment and devices used to perform single car air brake tests.  

Code of Federal Regulations, 2013 CFR

...Equipment and devices used to perform single car air brake tests. 232.309 Section...Equipment and devices used to perform single car air brake tests. (a) Equipment and devices used to perform single car air brake tests shall be tested for...

2013-10-01

260

49 CFR 232.309 - Equipment and devices used to perform single car air brake tests.  

Code of Federal Regulations, 2012 CFR

...Equipment and devices used to perform single car air brake tests. 232.309 Section...Equipment and devices used to perform single car air brake tests. (a) Equipment and devices used to perform single car air brake tests shall be tested for...

2012-10-01

261

Effect of cellular telephone conversations and other potential interference on reaction time in a braking response  

Microsoft Academic Search

This experiment studied the effect of phone conversations and other potential interference on reaction time (RT) in a braking response. Using a laboratory station which simulated the foot activity in driving, 22 research participants were requested to release the accelerator pedal and depress the brake pedal as quickly as possible following the activation of a red brake lamp. Mean reaction

William Consiglio; Peter Driscoll; Matthew Witte; William P. Berg

2003-01-01

262

Study of the nonlinear stationary dynamic of single and multi instabilities for disc brake squeal  

E-print Network

and prediction of squeal noise arising due to friction-induced vibrations in brake systems. To study the squealStudy of the nonlinear stationary dynamic of single and multi instabilities for disc brake squeal-jacques.sinou@ec-lyon.fr Abstract : The focus of this article is to show and discuss the nonlinear dynamical behaviors of brake

Boyer, Edmond

263

A global strategy based on experiments and simulations for squeal prediction on industrial railway brakes  

E-print Network

noise generated by high power railway disc brakes. 1 Introduction Friction-induced vibration and noise-related noise phenomena by classifying brake squeal mechanisms [8]. They also highlighted the nonlinear brakes J-J. Sinoua , A. Loyera,b,c , O. Chielloc,d , G. Mogeniera , X. Lorangb , F. Cocheteuxe and S

Paris-Sud XI, Université de

264

Instabilities in the sliding of continua with surface inertias: An initiation mechanism for brake noise  

Microsoft Academic Search

This paper presents a model for friction-induced vibration in brake systems, which takes a homogeneous tribological layer on the brake pad into account. The derived model consists of two flat elastic bodies sliding against each other with a constant coefficient of friction. In brake tribology, like in most tribological processes, a surface structure is observed, which can be modeled as

M. Graf; G.-P. Ostermeyer

2011-01-01

265

Motion capture of a pad measured with accelerometers during squeal noise in a real brake system  

E-print Network

Motion capture of a pad measured with accelerometers during squeal noise in a real brake system during squeal noise is measured on a real brake system with three-axis ac- celerometers. A time Brakes - 126 Rue de Stalingrad - 93700 DRANCY - FRANCE Abstract The operating deflection shape of a pad

Paris-Sud XI, Université de

266

Control Engineering Practice 11 (2003) 163170 A mechatronic conception of a new intelligent braking system  

E-print Network

, residual friction, noise, vibrations, a new brake has been designed according to a modular principle which braking system G.L. Gissingera, *, C. Menardb , A. Constansb a Laboratoire MIAM/ESSAIM, University describes a new intelligent braking system for motor vehicles. A mechatronic approach helped to avoid some

Paris-Sud XI, Université de

267

Analysis of brake squeal noise using the finite element method: A parametric study  

Microsoft Academic Search

Brake squeal noise has been under investigation by automotive manufacturers for decades due to consistent customer complaints and high warranty costs. J.D. Power surveys consistently show brake noise as being one of the most critical vehicle quality measurements. Furthermore, the development of methods to predict noise occurrence during the design of a brake system has been the target of many

Mário Trichês Júnior; Samir N. Y. Gerges; Roberto Jordan

2008-01-01

268

49 CFR 232.205 - Class I brake test-initial terminal inspection.  

Code of Federal Regulations, 2010 CFR

...of more than four hours; (4) A location where a unit or cycle train has traveled 3,000 miles since its last Class I brake...Class I brake test of a train shall consist of the following tasks and requirements: (1) Brake pipe leakage shall not...

2010-10-01

269

BRAKE CONTROL COMBINED WITH PREDICTION TO PREVENT THE ROLLOVER OF HEAVY VEHICLES  

Microsoft Academic Search

In this paper an active brake control to decrease the rollover risk of heavy vehicles is proposed. The brake system is activated when the vehicle comes close to rolling over. To enhance the performance of the active brake, this mechanism is extended with a prediction procedure, in which the critical values are predicted in advance using a short time interval.

P. Gaspar; Z. Szabo; J. Bokor

270

49 CFR 232.103 - General requirements for all train brake systems.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 false General requirements for all train brake systems. 232.103 Section... § 232.103 General requirements for all train brake systems. (a) The primary...10-inch diameters) brake cylinders, all cars shall have a legible decal,...

2010-10-01

271

Reduction of squeal noise from disc brake systems using constrained layer damping  

Microsoft Academic Search

Squeal noise generation during braking is a complic ated dynamic problem which automobile manufacturers have confronted for decade s. Customer complaints result in significant yearly warranty costs. More importantly , customer dissatisfaction may result in rejection of certain brands of brake systems. In or der to produce quality automobiles that can compete in today's marketplace, the occurrence of disc brake

M. Triches Jr; S. N. Y. Gerges; R. Jordan

2004-01-01

272

Reduction of automotive brake squeal through pad geometrical modifications: A numerical study  

Microsoft Academic Search

Reducing brake squeal noise for the improvement of ride comfort is one of the most important issues in today's automotive industry. This study details an investigation into the design modification of a brake pad for the front disc brake system as found on a typical passenger vehicle, and reports how the design modification can be improved to reduce the occurrence

C. Sujatha; M. Nouby; K. Srinivasan

2010-01-01

273

49 CFR 232.309 - Equipment and devices used to perform single car air brake tests.  

Code of Federal Regulations, 2010 CFR

...Equipment and devices used to perform single car air brake tests. 232.309 Section...Equipment and devices used to perform single car air brake tests. (a) Equipment and devices used to perform single car air brake tests shall be tested for...

2010-10-01

274

49 CFR 232.309 - Equipment and devices used to perform single car air brake tests.  

Code of Federal Regulations, 2011 CFR

...Equipment and devices used to perform single car air brake tests. 232.309 Section...Equipment and devices used to perform single car air brake tests. (a) Equipment and devices used to perform single car air brake tests shall be tested for...

2011-10-01

275

Fuzzy logic anti-lock brake system for a limited range coefficient of friction surface  

Microsoft Academic Search

Describes the preliminary research on and implementation of a fuzzy logic controller to control wheel slip for an antilock brake system. The dynamics of braking systems are highly nonlinear and time-variant. Simulation was used to derive an initial rule base, which was then tested on an experimental brake system. The rules were further refined by analysis of the data acquired

D. P. Madau; F. Yuan; L. A. Feldkamp

1993-01-01

276

Correcting Students' Misconceptions about Automobile Braking Distances and Video Analysis Using Interactive Program Tracker  

ERIC Educational Resources Information Center

The present paper informs about an analysis of students' conceptions about car braking distances and also presents one of the novel methods of learning: an interactive computer program Tracker that we used to analyse the process of braking of a car. The analysis of the students' conceptions about car braking distances consisted in…

Hockicko, Peter; Trpišová, Beáta; Ondruš, Ján

2014-01-01

277

Portable Hydraulic Powerpack  

NASA Technical Reports Server (NTRS)

Rechargeable hydraulic powerpack functions as lightweight, compact source of mechanical energy. Self-contained hydraulic powerpack derives energy from solid chemical charge. Combustion of charge initiated by small hammer, and revolving feeder replaces charges expended. Combustion gases cool during expansion in turbine and not too hot for release to atmosphere. Unit has applications driving wheelchairs and operating drills, winches, and other equipment in remote areas. Also replaces electric motors and internal-combustion engines as source of power in explosive atmospheres.

Anderson, L. A.; Henry, R. L.; Fedor, O. H.; Owens, L. J.

1986-01-01

278

49 CFR 232.109 - Dynamic brake requirements.  

Code of Federal Regulations, 2010 CFR

... (2) Display in real-time in the cab of the...at the grids on the system; and (2) Display...deceleration rate or in real-time in the cab of the... (j) A railroad operating a train with a brake system that includes...

2010-10-01

279

49 CFR 232.109 - Dynamic brake requirements.  

Code of Federal Regulations, 2011 CFR

... (2) Display in real-time in the cab of the...at the grids on the system; and (2) Display...deceleration rate or in real-time in the cab of the... (j) A railroad operating a train with a brake system that includes...

2011-10-01

280

49 CFR 232.109 - Dynamic brake requirements.  

Code of Federal Regulations, 2012 CFR

... (2) Display in real-time in the cab of the...at the grids on the system; and (2) Display...deceleration rate or in real-time in the cab of the... (j) A railroad operating a train with a brake system that includes...

2012-10-01

281

14 CFR 27.493 - Braked roll conditions.  

Code of Federal Regulations, 2012 CFR

...a)(2); and (b) The structure must be designed to withstand at the ground contact point of each wheel with brakes, a drag load at least the lesser of— (1) The vertical load multiplied by a coefficient of friction of 0.8; and (2) The...

2012-01-01

282

14 CFR 29.493 - Braked roll conditions.  

Code of Federal Regulations, 2012 CFR

...2); and (b) The structure must be designed to withstand, at the ground contact point of each wheel with brakes, a drag load of at least the lesser of— (1) The vertical load multiplied by a coefficient of friction of 0.8; and (2)...

2012-01-01

283

14 CFR 29.493 - Braked roll conditions.  

Code of Federal Regulations, 2011 CFR

...2); and (b) The structure must be designed to withstand, at the ground contact point of each wheel with brakes, a drag load of at least the lesser of— (1) The vertical load multiplied by a coefficient of friction of 0.8; and (2)...

2011-01-01

284

Real-time brake torque estimation for internal combustion engines  

NASA Astrophysics Data System (ADS)

Presented is a real-time engine brake torque estimation model where the instantaneous measured engine speed serves as the model input. The model is comprised of notch filters executed in the crank-angle domain to extract mean engine speed and the nth frequency component from the instantaneous engine speed signal in real-time. Here n denotes the number of engine cylinders. Moreover, the engine brake torque estimation is separated into two parts: steady-state and transient. It will be shown that the nth harmonic (in units of periods per engine cycle) of engine speed and mean engine speed are sufficient to estimate the engine brake torque. The steady-state portion of the model is developed using orthogonal least-squares estimation and results in a model with 15 regressors for our particular case. The transient portion is identified using a time domain identification method. Validation of the engine brake torque model is provided using a computational engine model for a 6-cylinder heavy duty diesel engine. Transient engine speed and torque conditions in the presence of sensor noise are evaluated as well as cylinder power imbalance scenarios.

Franco, Javier; Franchek, Matthew A.; Grigoriadis, Karolos

2008-02-01

285

Three Dimensional Animation of a Disc Brake System Generating Noise  

Microsoft Academic Search

Brake noise investigations using the whole body visual technique of double pulsed holographic interferometry have been extended so that a series of time related interferograms may be recorded over a cycle of excitation. The main disadvantage of such a technique is that the extraction of the valuable information contained within the holograms requires a degree of expertise in the interpretation

Chris Talbot; Kamal-al Banawi; John D Fieldhouse

286

HYDRO BRAKE REGULATED STORAGE SYSTEM FOR STORMWATER MANAGEMENT  

EPA Science Inventory

This research project was initiated with the overall objective of determining the ability of the Hydro Brake flow control device, in conjunction with off-line underground storage, to limit the rate of stormwater flow into combined sewers. The intended result of this control was t...

287

Wear and related characteristics of an aircraft tire during braking  

NASA Technical Reports Server (NTRS)

Wear and related characteristics of friction and temperature developed during braking of size 22 x 5.5, type aircraft tires are studied. The testing technique involved gearing the tire to a driving wheel of a ground vehicle to provide operations at constant slip ratios on asphalt, concrete, and slurry-seal surfaces. Data were obtained over the range of slip ratios generally attributed to an aircraft braking system during dry runway operations. The results show that the cumulative tire wear varies linearly with distance traveled and the wear rate increases with increasing slip ratio and is influenced by the runway-surface character. Differences in the wear rates associated with the various surfaces suggest that runways can be rated on the basis of tire wear. The results also show that the friction coefficients developed during fixed-slip-ratio operations are in good agreement with those obtained by other investigators during cyclic braking, in that the dry friction is insensitive to the tire tread temperature is shown to increase with increasing slip ratio and, at the higher ratios, to be greater during braking on asphalt and slurry seal than on concrete.

Mccarty, J. L.

1972-01-01

288

Dr.-Ing. Norbert Frhleke PIBRAC -Piezoelectrical Brake Actuator  

E-print Network

-mass ultrasonic Power supply and control development Dr.-Ing. Norbert Fröhleke, Department of Power Electronics Böcker, Dr.-Ing. Norbert Fröhleke Current Aircraft Brake Actuator #12;Power Electronics and Electrical, Dr.-Ing. Norbert Fröhleke Inverter and filter Power supply control motor control actuator control

Paderborn, Universität

289

44. SOUTHWEST TO CIRCA 1900 SHEET METAL BRAKE, THE MACHINE ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

44. SOUTHWEST TO CIRCA 1900 SHEET METAL BRAKE, THE MACHINE USED TO BEND SHEET METAL TO EXACT ANGLES AS IN STEEL WATER TANK MANUFACTURE. IN THE BACKGROUND IS THE INTERIOR WEST WALL OF THE FACTORY, ITS SHELVES BEARING WATER PUMPS, PARTS FOR PUMPS AND WATER SUPPLY EQUIPMENT, AND NEW OLD STOCK MERCHANDISE. - Kregel Windmill Company Factory, 1416 Central Avenue, Nebraska City, Otoe County, NE

290

49 CFR 393.42 - Brakes required on all wheels.  

Code of Federal Regulations, 2010 CFR

...Trucks or truck tractors having three...brakes provided the combination of vehicles meets...and (ii) Any combination of motor vehicles...semitrailer or pole trailer (laden or...dollies, specialized trailers and dollies used...speed at which the combination of vehicles...

2010-10-01

291

Tribological properties of automotive disc brakes with solid lubricants  

Microsoft Academic Search

In automotive brake systems, high temperatures and pressures are generated at the contacting surfaces. This affects the pad and disc materials, creating a friction film between the surfaces, which consists of wear particles and volatile reactants from the pad and disc. To acquire suitable tribological properties, a pad matrix contains up to 20 different ingredients, mainly selected from experience. In

Luise Gudmand-Høyer; Allan Bach; Georg T Nielsen; Per Morgen

1999-01-01

292

27. Historic drawing, Marine Railway. Detail of Emergency Brake, 1917. ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

27. Historic drawing, Marine Railway. Detail of Emergency Brake, 1917. Photographic copy of original. Boston National Historical Park Archives, Charlestown Navy Yard. BOSTS 13439, #551-16 - Charlestown Navy Yard, Marine Railway, Between Piers 2 & 3, on Charlestown Waterfront at west end of Navy Yard, Boston, Suffolk County, MA

293

14 CFR 23.493 - Braked roll conditions.  

...479 for level landings. (c) A drag reaction equal to the vertical reaction at the wheel multiplied by a coefficient of friction of 0.8 must be applied at the ground contact point of each wheel with brakes, except that the drag reaction...

2014-01-01

294

14 CFR 23.493 - Braked roll conditions.  

Code of Federal Regulations, 2012 CFR

...479 for level landings. (c) A drag reaction equal to the vertical reaction at the wheel multiplied by a coefficient of friction of 0.8 must be applied at the ground contact point of each wheel with brakes, except that the drag reaction...

2012-01-01

295

14 CFR 23.493 - Braked roll conditions.  

Code of Federal Regulations, 2013 CFR

...479 for level landings. (c) A drag reaction equal to the vertical reaction at the wheel multiplied by a coefficient of friction of 0.8 must be applied at the ground contact point of each wheel with brakes, except that the drag reaction...

2013-01-01

296

Oxygen-Diffused Titanium as a Candidate Brake Rotor Material  

SciTech Connect

Titanium alloys are one of several candidate materials for the next generation of truck disk brake rotors. Despite their advantages of lightweight relative to cast iron and good strength and corrosion resistance, titanium alloys are unlikely to be satisfactory brake rotor materials unless their friction and wear behavior can be significantly improved. In this study, a surface engineering process oxygen diffusion was applied to titanium rotors and has shown very encouraging results. The oxygen diffused Ti-6Al-4V (OD-Ti) was tested on a sub-scale brake tester against a flat block of commercial brake lining material and benchmarked against several other Ti-based materials, including untreated Ti-6Al-4V, ceramic particle-reinforced Ti composites (MMCs), and a thermal-spray-coated Ti alloy. With respect to friction, the OD-Ti outperformed all other candidate materials under the imposed test conditions with the friction coefficient remaining within a desirable range of 0.35-0.50, even under the harshest conditions when the disk surface temperature reached nearly 600 ?C. In addition, the OD-Ti showed significantly improved wear-resistance over the non-treated one and was even better than the Ti-based composite materials.

Qu, Jun [ORNL; Blau, Peter Julian [ORNL; Jolly, Brian C [ORNL

2009-01-01

297

Fleet study evaluation of an advance brake warning system.  

PubMed

The advance brake warning system (ABWS) is a mechanism that activates the brake lights in response to a rapid disengagement of the gas pedal, before the driver's foot reaches the brake pedal. Two previous studies showed that (a) such rapid releases of the gas pedal are typically followed by brake activation, and (b) the ABWS can prevent a high percentage of rear-end collisions in which an attentive following driver maintains a headway of 1.0 s or less from the vehicle ahead. In the present study the crash involvement of 764 government cars and light trucks was tracked over an average period of 35 months. The vehicles were matched in pairs--one of each pair with the ABWS and one without it. Data analyses focused on collisions in which the government vehicles were rear-ended. Overall, ABWS-equipped vehicles were not significantly less involved in rear-end collisions. However, an examination of the struck vehicles only showed that the ABWS-equipped vehicles were involved in fewer rear-end collisions per kilometer driven than were the vehicles without the ABWS. In conclusion, despite the theoretical appeal and the results of earlier studies, the fleet study failed to demonstrate that such a system is a cost-effective safety device for the prevention of rear-end crashes. Actual or potential applications include the evaluation of new in-vehicle technologies by a hierarchy of multiple validation studies prior to consideration. PMID:11132809

Shinar, D

2000-01-01

298

6. OBLIQUE VIEW OF HOIST, SHOWING WOODEN BRAKE SHOES, REDUCTION ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

6. OBLIQUE VIEW OF HOIST, SHOWING WOODEN BRAKE SHOES, REDUCTION GEARS AND BED FOR (MISSING) CLUTCH/DRIVE GEAR UNIT, LOOKING NORTHWEST - Buffalo Coal Mine, Vulcan Cable Hoist, Wishbone Hill, Southeast end, near Moose Creek, Sutton, Matanuska-Susitna Borough, AK

299

DISC BRAKE SYSTEM (CENTER), INCLUDING BELT DRIVE TO SECONDARY GENERAL ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

DISC BRAKE SYSTEM (CENTER), INCLUDING BELT DRIVE TO SECONDARY GENERAL MOTORS ENGINE (LEFT)AND FERREL REDUCTION GEAR CONNECTION TO ALLIS-CHALMERS DIESEL ENGINE (RIGHT), LOOKING NORTH. NOTE TORQUE CONVERTER (TOP) AND THROTTLE (BELOW) LINES CONNECTING TO PRIMARY ENGINE. - Mad River Glen, Single Chair Ski Lift, 62 Mad River Glen Resort Road, Fayston, Washington County, VT

300

5. Machine shop and air brake shop sections of roundhouse ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

5. Machine shop and air brake shop sections of roundhouse in background. Foundry (MN-99-B) in foreground. View to south. - Duluth & Iron Range Rail Road Company Shops, Roundhouse, Southwest of downtown Two Harbors, northwest of Agate Bay, Two Harbors, Lake County, MN

301

Theoretical and experimental studies on a magnetorheological brake operating under compression plus shear mode  

NASA Astrophysics Data System (ADS)

The torque characteristics of magnetorheological brakes, consisting of rotating disks immersed in a MR fluid and enclosed in an electromagnetic casing, are controlled by regulating the yield stress of the MR fluid. An increase in yield stress increases the braking torque, which means that the higher the yield strength of the MR fluid, the better the performance of the MR brake will be. In the present research an application of compressive force on MR fluid has been proposed to increase the torque capacity of MR brakes. The mathematical expressions to estimate the torque values for MR brake, operating under compression plus shear mode accounting Herschel-Bulkley shear thinning model, have been detailed. The required compressive force on MR fluid of the proposed brake has been applied using an electromagnetic actuator. The development of a single-plate MR disk brake and an experimental test rig are described. Experiments have been performed to illustrate braking torque under different control currents (0.0-2.0 A). The torque results have been plotted and compared with theoretical study. Experimental results as well as theoretical calculations indicate that the braking torque of the proposed MR brake is higher than that of the MR brake operating only under shear.

Sarkar, C.; Hirani, H.

2013-11-01

302

Guidelines for numerical vibration and acoustic analysis of disc brake squeal using simple models of brake systems  

NASA Astrophysics Data System (ADS)

Brake squeal has become of increasing concern to the automotive industry but guidelines on how to confidently predict squeal propensity are yet to be established. While it is standard practice to use the complex eigenvalue analysis to predict unstable vibration modes, there have been few attempts to calculate their acoustic radiation. Here guidelines are developed for numerical vibration and acoustic analysis of brake squeal using models of simplified brake systems with friction contact by considering (1) the selection of appropriate elements, contact and mesh; (2) the extraction of surface velocities via forced response; and (3) the calculation of the acoustic response itself. Results indicate that quadratic tetrahedral elements offer the best option for meshing more realistic geometry. A mesh has to be sufficiently fine especially in the contact region to predict mesh-independent unstable vibration modes. Regarding the vibration response, only the direct, steady-state method with a pressurised pad and finite sliding formulation (allowing contact separation) should be used. Comparison of different numerical methods suggest that a obroadband fast multi-pole boundary element method with the Burton-Miller formulation would efficiently solve the acoustic radiation of a full brake system. Results also suggest that a pad lift-off can amplify the acoustic radiation similar to a horn effect. A horn effect is also observed for chamfered pads which are used in practice to reduce the number and strength of unstable vibration modes. These results highlight the importance of optimising the pad shape to reduce acoustic radiation of unstable vibration modes.

Oberst, S.; Lai, J. C. S.; Marburg, S.

2013-04-01

303

TU Delft: Hydraulic Engineering  

NSDL National Science Digital Library

Given the Dutch reputation for water management, it's no surprise that one of their leading technical institutes, The Technische Universiteit Delft, offers a program in Hydraulic Engineering. The website, in both Dutch and English, describes their program as an attempt "to bridge the gap between basic sciences (fluid mechanics and soil mechanics in particular) and practical engineering applications in the design, construction, maintenance, management and eventually the demolition of hydraulic structures." The Education section of the website posts MSc theses completed by their students. The research section describes current and recently completed research projects and includes a listing of publications, some of which are available to download. The website also has a link to a Hydraulic Engineering portal, which offers various publication databases (some in Dutch only), and the Civil Engineering Knowledge Centre, which provides library access and discussion forums for students and staff of Civil Engineering.

304

Hydraulics of wells  

USGS Publications Warehouse

Although the subject of this lecture is supposed to be concerned primarily with the hydraulics of wells, Professor Weers has asked that I also discuss the effects tat geological formations have on the quantity and quality of water available to wells. I will discuss the geology of Colorado in relation to the availability and quality of water with particular reference to the most productive aquifers or water-bearing formations in the State. I will then discuss the hydraulics of wells with the aim of emphasizing the differences between water-table and artesian conditions.

McLaughlin, Thad G.

1955-01-01

305

What Is Hydraulic Fracturing?  

NSDL National Science Digital Library

Hydraulic fracturing is a process used in nine out of 10 natural gas wells in the United States, where millions of gallons of water, sand and chemicals are pumped underground to break apart the rock and release the gas. Scientists are worried that the chemicals used in fracturing may pose a threat either underground or when waste fluids are handled and sometimes spilled on the surface. This poster presentation illustrates the under surface process of hydraulic fracking and the distribution flow to the market.

2012-01-01

306

Geostatistical inference of hydraulic conductivity and dispersivities from hydraulic heads and tracer data  

E-print Network

Geostatistical inference of hydraulic conductivity and dispersivities from hydraulic heads; accepted 25 April 2006; published 10 August 2006. [1] In groundwater, hydraulic heads and solute arrival times depend primarily on the hydraulic conductivity field and hydraulic boundary conditions. The spread

Cirpka, Olaf Arie

307

Laboratory Determination of Hydraulic Conductivity  

NSDL National Science Digital Library

From D.B. McWhorterand D. K. Sunda's 1977 Ground-Water Hydrology and Hydraulics, this two page excerpt outlines and details Laboratory Determination of Hydraulic Conductivity. Here, visitors will find illustrations and formula to understand the concept.

308

Heavy and Overweight Vehicle Brake Testing: Five-Axle Combination Tractor-Flatbed Final Report  

SciTech Connect

The Federal Motor Carrier Safety Administration, in coordination with the Federal Highway Administration, sponsored the Heavy and Overweight Vehicle Brake Testing (HOVBT) program in order to provide information about the effect of gross vehicle weight (GVW) on braking performance. Because the Federal Motor Carrier Safety Regulations limit the number of braking system defects that may exist for a vehicle to be allowed to operate on the roadways, the examination of the effect of brake defects on brake performance for increased loads is also relevant. The HOVBT program seeks to provide relevant information to policy makers responsible for establishing load limits, beginning with providing test data for a combination tractor/trailer. This testing was conducted on a five-axle combination vehicle with tractor brakes meeting the Reduced Stopping Distance requirement rulemaking. This report provides a summary of the testing activities, the results of various analyses of the data, and recommendations for future research. Following a complete brake rebuild, instrumentation, and brake burnish, stopping tests were performed from 20 and 40 mph with various brake application pressures (15 psi, 25 psi, 35 psi, 45 psi, 55 psi, and full system pressure). These tests were conducted for various brake conditions at the following GVWs: 60,000, 80,000, 91,000, 97,000, 106,000, and 116,000 lb. The 80,000-lb GVWs included both balanced and unbalanced loads. The condition of the braking system was also varied. To introduce these defects, brakes (none, forward drive axle, or rear trailer axle) were made inoperative. In addition to the stopping tests, performance-based brake tests were conducted for the various loading and brake conditions. Analysis of the stopping test data showed the stopping distance to increase with load (as expected) and also showed that more braking force was generated by the drive axle brakes than the trailer axle brakes. The constant-pressure stopping test data revealed a linear relationship between brake application pressure and was used to develop an algorithm to normalize stopping data for weight and initial speed.

Lascurain, Mary Beth [ORNL; Capps, Gary J [ORNL; Franzese, Oscar [ORNL

2013-10-01

309

Anti-lock brake system: an assessment of training on driver effectiveness.  

PubMed

When activated correctly, Anti-Lock Brake Systems (ABS) can provide drivers with the ability to stop a vehicle in shorter distances and allow for more vehicle control under heavy braking than conventional brake systems. This is especially true under wet or icy road conditions. However, it is believed that many drivers are either unaware of the correct method of activation or they revert back to the old method of pumping the brakes when they are faced with a hard braking situation. This paper examines the effectiveness of implementing low-cost training methods for alerting drivers to the correct brake activation technique. A 4-page, color training pamphlet was developed and subjects were given a short period of time to read it over before being asked to drive on an icy test track. Results indicated that those subjects who received the training were able to stop in shorter distances in a straight line braking event and more often used the correct brake activation technique than those subjects who did not receive the training. However, the stopping distance benefits were not realized in the curved and surprise braking events. These results suggest that the transfer of verbal knowledge may have value as a means for solving the apparent problem of improper ABS usage. However, some additional research should be done to validate these results. Since this experiment was conducted directly after the material was read, the possibility exists that without reinforcement, the trained braking techniques might become extinct in a short period of time. PMID:9110044

Mollenhauer, M A; Dingus, T A; Carney, C; Hankey, J M; Jahns, S

1997-01-01

310

Hydroinformatics at Delft Hydraulics  

Microsoft Academic Search

Hydroinformatics represents a technological challenge for a research and consultancy organisation such as DELFT HYDRAULICS. Building problem-solving systems by combining numerical models with computer technologies such as databases, geographical information systems (GIS), visualization systems, artificial intelligence and intelligent user interfaces, is only part of the work. The other part is quality control: ensuring that the results obtained with hydroinformatics systems

H. J. Van Zuylen; D. P. Dee; Ir. A. E. Mynett; G. S. Rodenhuis; Ir. J. R. Moll; Ir. H. J. M. Ogink; Ir. H. V. D. Most; Ir. H. Gerritsen; G. K. Verboom

1994-01-01

311

Water Treatment Technology - Hydraulics.  

ERIC Educational Resources Information Center

One of twelve water treatment technology units, this student manual on hydraulics provides instructional materials for three competencies. (The twelve units are designed for a continuing education training course for public water supply operators.) The competencies focus on the following areas: head loss in pipes in series, function loss in…

Ross-Harrington, Melinda; Kincaid, G. David

312

Hydraulic Shutdown Monitor  

NASA Technical Reports Server (NTRS)

Adding switch allows inappropriate control actions to be overridden. Four-pole, double-throw switch added to front panel of controller to disable tracking-error and endpoint-error circuitry yet still retain overload-detection capability. Previously, it was necessary to use adjustable-voltage-level detection equipment connected with cables to hydraulic "dump" or shutdown circuitry in controller.

Fleming, S. T.; Harrington, D. B.

1986-01-01

313

Integration in Hydraulics.  

ERIC Educational Resources Information Center

This paper presents an application of integration to the field of hydraulics. An integral relation for the time required to drop the fluid contained in a cylindrical tank from one level to another using a hole in the tank wall is derived. Procedures for constructing the experimental equipment and procedures for determining the coefficient of…

Sworder, Steven C.

314

Viscous Hydraulic Jumps Submitted by  

E-print Network

Viscous Hydraulic Jumps Submitted by Jeffrey M. Aristoff, Jeffrey D. Leblanc, Annette E. Hosoi, and John W. M. Bush, Massachusetts Institute of Technology We examine the form of the viscous hydraulic of height 2­10 mm. Elegaard et al.1 first demonstrated that the axial symme- try of the viscous hydraulic

Bush, John W.M.

315

Calculator programs determine drilling hydraulics  

Microsoft Academic Search

Two TI-59 programs were prepared for the calculation of drilling hydraulics as set forth in the Hughes Tool Co. publication, Practical Hydraulics. One presents the stepwise determination of drill string pressure drop while the second, to be published in a future issue, calculates jet area, jet velocity and impact force along with bit pressure drop and hydraulic horsepower. Another section

Landry

1987-01-01

316

Calculator programs determine drilling hydraulics  

Microsoft Academic Search

This paper describes Hydraulics II, which is prepared for the calculation of bit hydraulics and pump performance on the TI-59 using a PC-100C printer. The operator is prompted for the required input data with a printed register number and an abbreviated title. Output is printed and labeled. As in Hydraulics I, three magnetic cards are required, two for the program

Landry

1987-01-01

317

Computer simulation of hydraulic fractures  

Microsoft Academic Search

We provide a brief historical background of the development of hydraulic fracturing models for use in the petroleum and other industries. We discuss scaling laws and the propagation regimes that control the growth of hydraulic fractures from the laboratory to the field scale. We introduce the mathematical equations and boundary conditions that govern the hydraulic fracturing process, and discuss numerical

J. Adachi; E. Siebrits; A. Peirce; J. Desroches

2007-01-01

318

Water Resources: Hydraulics and Hydrology  

E-print Network

Water Resources: Hydraulics and Hydrology Interview with Margaret S. Petersen #12;This manuscript RESOURCES: HYDRAULICS AND HYDROLOGY #12;Approved for public release distribution IS unlimited. #12;Preface The United States Army Corps of Engineers significantly contributed to hydraulic and hydrologic engineering

US Army Corps of Engineers

319

Design principles of descent vehicles with an inflatable braking device  

NASA Astrophysics Data System (ADS)

A new type of descent vehicle (DVs) is described: a descent vehicle with an inflatable braking device (IBD DV). IBD development issues, as well as materials needed for the design, manufacturing, and testing of an IBD and its thermal protection, are discussed. A list is given of Russian integrated test facilities intended for testing IBD DVs. Progress is described in the development of IBD DVs in Russia and abroad.

Alexashkin, S. N.; Pichkhadze, K. M.; Finchenko, V. S.

2013-12-01

320

Evaluation of asbestos exposure during brake repair and replacement.  

PubMed

Occupational exposure to asbestos fiber of brake repair job (auto mechanics) has seldom been evaluated in Iran. Accordingly, we evaluated asbestos fiber concentrations in the breathing zone of auto mechanics between July 2008 and December 2008. The asbestos fiber concentrations of 60 personal air samples collected from 30 cars and trucks brake replacement and they were analyzed by phase-contrast optical microscopy (PCM) and scanning electron microscopy (SEM) by energy-dispersive X-ray analysis. The geometric means of the personal monitoring fiber concentrations were 0.92 PCM f/ml and 0.46 PCM f/ml respectively in car and passenger heavy truck auto shops. There was a significant differences in the asbestos fiber concentrations between the car and truck auto shops (p=0.006). Based on these findings, auto mechanics who worked with asbestos containing brake may have been exposed to asbestos concentrations approximately 7 times higher than the current occupational safety and health agency (OSHA) permissible exposure limit (PEL) of 0.1 f/ml. Fiber morphology and energy dispersive X-ray analysis by SEM revealed that amphibole fibers such as tremolite and actinolite existed in the brakes dust and that the vast majority (>30%) of the airborne chrysotile fibers were greater than 1 ?m in diameter. It can be concluded that the imported chrysotile asbestos contains trace amounts of tremolite and actinolite fibers and they are responsible for the high airborne asbestos levels and occupational exposure to amphibole asbestos in auto mechanics job in Iran. Thus, it is to be expected that the auto mechanics will suffer negative health effects due to exposure to the serpentine and amphibole asbestos fibers. PMID:21372435

Kakooei, Hossein; Hormozy, Maryam; Marioryad, Hossein

2011-01-01

321

Friction and wear behavior of carbon fiber reinforced brake materials  

Microsoft Academic Search

A new composite brake material was fabricated with metallic powders, barium sulphate and modified phenolic resin as the matrix\\u000a and carbon fiber as the reinforced material. The friction, wear and fade characteristics of this composite were determined\\u000a using a D-MS friction material testing machine. The surface structure of carbon fiber reinforced friction materials was analyzed\\u000a by scanning electronic microscopy (SEM).

Du-qing Cheng; Xue-tao Wang; Jian Zhu; Dong-hua Qiu; Xiu-wei Cheng; Qing-feng Guan

2009-01-01

322

A robust active control method to reduce brake noise  

Microsoft Academic Search

In this paper, a novel approach to suppress vibration that causes brake noise is proposed employing a closed-loop feedback control method using an Active Force Control (AFC) based strategy. It is used in conjunction with the classic proportional-integral-derivative (PID) scheme that is typically incorporated in the outermost positional control loop. The idea is to introduce an active element that dynamically

S. M. Hashemi-Dehkordi; M. Mailah; A. R. Abu-Bakar

2009-01-01

323

Noise and Vibration Modeling for Anti-Lock Brake Systems  

Microsoft Academic Search

\\u000a A new methodology is proposed for noise and vibration analysis for Anti-Lock Brake Systems (ABS). First, a correlation between\\u000a noise and vibration measurement data and simulation results need to be established. This relationship allows the engineers\\u000a to focus on modeling and simulation instead of noise and vibration testing. A comprehensive ABS model is derived for noise\\u000a and vibration study. The

Wei Zhan

2008-01-01

324

Energy Efficiency in Heavy Vehicle Tires, Drivetrains, and Braking Systems  

SciTech Connect

This document was prepared to support the primary goals of the Department of Energy, Office of Heavy Vehicle Technologies. These were recently stated as follows: ''Develop by 2004 the enabling technologies for a class 7-8 truck with a fuel efficiency of 10 mpg (at 65 mph) which will meet prevailing emission standards. For Class 3-6 trucks operating on an urban driving cycle, develop by 2004 commercially viable vehicles that achieve at least double the fuel economy of comparable current vehicles (1999), and as a research goal, reduce criteria pollutants to 30% below EPA standards. Develop by 2004 the diesel engine enabling technologies to support large-scale industry dieselization of Class 1 and 2 trucks, achieving a 35 % fuel efficiency improvement over comparable gasoline-fueled trucks, while meeting applicable emissions standards.'' The enabling technologies for improving the fuel efficiency of trucks, include not only engine technologies but also technologies involved with lowering the rolling resistance of tires, reducing vehicle aerodynamic drag, improving thermal management, and reducing parasitic frictional losses in drive train components. Opportunities also exist for making better use of the energy that might ordinarily be dissipated during vehicle braking. Braking systems must be included in this evaluation since safety in truck operations is vital, and braking requirements are greater for vehicles having lowered resistance to rolling. The Office of Heavy Vehicle Technologies has initiated a program to improve the aerodynamics of heavy vehicles through wind tunnel testing, computational modeling, and on-road evaluations. That activity is described in a separate multi-year plan; therefore, emphasis in this document will be on tires, drive trains, and braking systems. Recent, dramatic fluctuations in diesel fuel prices have emphasized the importance of effecting savings in truck fuel economy by implementing new component designs and materials.

Peter J. Blau

2000-04-26

325

Simulation study of the plasma-brake effect  

NASA Astrophysics Data System (ADS)

Plasma brake is a thin, negatively biased tether that has been proposed as an efficient concept for deorbiting satellites and debris objects from low Earth orbit. We simulate the interaction with the ionospheric plasma ram flow with the plasma-brake tether by a high-performance electrostatic particle in cell code to evaluate the thrust. The tether is assumed to be perpendicular to the flow. We perform runs for different tether voltage, magnetic-field orientation and plasma-ion mass. We show that a simple analytical thrust formula reproduces most of the simulation results well. The interaction with the tether and the plasma flow is laminar (i.e. smooth and not turbulent) when the magnetic field is perpendicular to the tether and the flow. If the magnetic field is parallel to the tether, the behaviour is unstable and thrust is reduced by a modest factor. The case in which the magnetic field is aligned with the flow can also be unstable, but does not result in notable thrust reduction. We also correct an error in an earlier reference. According to the simulations, the predicted thrust of the plasma brake is large enough to make the method promising for low-Earth-orbit (LEO) satellite deorbiting. As a numerical example, we estimate that a 5 km long plasma-brake tether weighing 0.055 kg could produce 0.43 mN breaking force, which is enough to reduce the orbital altitude of a 260 kg object mass by 100 km over 1 year.

Janhunen, P.

2014-10-01

326

9. VIEW SOUTHWEST OF PRIMARY REDUCING GEARS; NOTE BRAKE WHEEL ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

9. VIEW SOUTHWEST OF PRIMARY REDUCING GEARS; NOTE BRAKE WHEEL AND PADS AT RIGHT CENTER BEHIND PRIMARY GEAR; MITER GEAR AT CENTER IS PART OF MECHANISM FOR MANUAL OPERATION OF BRIDGE; FLANGE FOR COUPLING THE NORTH AND SOUTH REDUCTION GEAR TRAINS IS AT CENTER OF PHOTOGRAPH BEHIND SOUTH PRIMARY REDUCTION GEAR - East Washington Avenue Bridge, Spanning Pequonnock River at East Washington Avenue, Bridgeport, Fairfield County, CT

327

Predictive model of squeal noise occurring on a laboratory brake  

NASA Astrophysics Data System (ADS)

This paper on brake squeal instability presents a reduced order model of a laboratory brake considered in a previous paper, and presents a description of the squeal mechanism occurring during experiments. The model uses the modal parameters of the laboratory brake components, the disc and the caliper, when they are not in contact between them. Successively, the caliper and the disc are put in contact through the pad that is modeled as a one degree of freedom system while the Coulomb law models the friction interaction between them. No stick slip motion of the pad is considered, because it was not observed in the experimental tests. As a result the model is linear and particularly suited for a parametric analysis. The stability of the model is studied by a complex eigenvalue analysis and the obtained results show a good agreement with the experimental data, provided that the key parameters of the model are consistent with the experimental set-up. The key role of the disc and the pad dynamics are discussed.

Giannini, Oliviero; Sestieri, Aldo

2006-09-01

328

SPINDOWN OF ISOLATED NEUTRON STARS: GRAVITATIONAL WAVES OR MAGNETIC BRAKING?  

SciTech Connect

We study the spindown of isolated neutron stars from initially rapid rotation rates, driven by two factors: (1) gravitational wave emission due to r-modes and (2) magnetic braking. In the context of isolated neutron stars, we present the first study including self-consistently the magnetic damping of r-modes in the spin evolution. We track the spin evolution employing the RNS code, which accounts for the rotating structure of neutron stars for various equations of state. We find that, despite the strong damping due to the magnetic field, r-modes alter the braking rate from pure magnetic braking for B {<=} 10{sup 13} G. For realistic values of the saturation amplitude {alpha}{sub sat}, the r-mode can also decrease the time to reach the threshold central density for quark deconfinement. Within a phenomenological model, we assess the gravitational waveform that would result from r-mode-driven spindown of a magnetized neutron star. To contrast with the persistent signal during the spindown phase, we also present a preliminary estimate of the transient gravitational wave signal from an explosive quark-hadron phase transition, which can be a signal for the deconfinement of quarks inside neutron stars.

Staff, Jan E. [Department of Physics and Astronomy, Louisiana State University, 202 Nicholson Hall, Tower Drive, Baton Rouge, LA 70803-4001 (United States); Jaikumar, Prashanth; Chan, Vincent [Department of Physics and Astronomy, California State University Long Beach, 1250 Bellflower Boulevard, Long Beach, CA 90840 (United States); Ouyed, Rachid [Department of Physics and Astronomy, University of Calgary, 2500 University Drive NW, Calgary, Alberta T2N 1N4 (Canada)

2012-05-20

329

Evaluation of Army engine oils in hydraulic/power-transmission-system components. Final report, August 1984-November 1985  

SciTech Connect

The objective of the MACI Hydraulic System and Components Program is to perform technical evaluation and assessment of commerically available qualified and fielded Army engine oils and to determine if such oils can be used as hydraulic fluids in Army commercial construction equipment and material-handling equipment. Five Army specification engine lubricants--four MIL-L-2104D (one grade 10W, one grade 30, two grade 15W-40) and one MIL-L-46167, grade 0W-20--were evaluated using four critical component performance tests used by manufacturers. Data compiled from this and previous work have shown that the limiting factors of the Army engine oils used as hydraulic and multipurpose power transmission fluids appear to be (1) wet-brake chatter noise, (2) hydraulic-pump wear problems with some piston pumps using MIL-L-46167 Arctic engine oils at temperatures hotter-than-expected Arctic conditions, and possibly (3) copper corrosion. The prime area of concern is the wet-brake chatter noise.

Marbach, H.W.; Lestz, S.J.

1985-11-01

330

Design of a microprocessor based novel braking of three phase induction motor  

SciTech Connect

This paper describes the development of an efficient braking system suitable for three phase induction motor drives specially driving loads of non-overhauling type. The method incorporates a combination of three braking methods in four states according to the speed range at which the respective methods are most effective, with the result of a smooth and efficient braking. First capacitor self-excitation is applied in stages followed by magnetic braking by double short circuiting and dc injection. Theoretical and experimental results for determining different parameters useful for designing the braking scheme are provided. Lastly microprocessor has been used for proper incorporation of different braking schemes. Dual switching scheme has improved the reliability of the scheme.

Sinha, N.; Laskar, S.H.; Goyal, K.; Nair, P.B.; Sharma, M.K. [Regional Engineering Coll., Silchar (India)

1995-12-31

331

Iteration theory of L-index and multiplicity of brake orbits  

NASA Astrophysics Data System (ADS)

In this paper, we first establish the Bott-type iteration formulas and some abstract precise iteration formulas of the Maslov-type index theory associated with a Lagrangian subspace for symplectic paths. As an application, we prove that there exist at least [n/2]+1 geometrically distinct brake orbits on every C2 compact convex symmetric hypersurface ? in R2n satisfying the reversible condition N?=?. Furthermore, if all brake orbits on this hypersurface are nondegenerate, then there are at least n geometrically distinct brake orbits on it. As a consequence, we show that there exist at least [n/2]+1 geometrically distinct brake orbits in every bounded convex symmetric domain in Rn. Furthermore, if all brake orbits in this domain are nondegenerate, then there are at least n geometrically distinct brake orbits in it. In the symmetric case, we give a positive answer to the Seifert conjecture of 1948 under a generic condition.

Liu, Chungen; Zhang, Duanzhi

2014-08-01

332

Hydraulic manipulator research at ORNL  

SciTech Connect

Recently, task requirements have dictated that manipulator payload capacity increase to accommodate greater payloads, greater manipulator length, and larger environmental interaction forces. General tasks such as waste storage tank cleanup and facility dismantlement and decommissioning require manipulator life capacities in the range of hundreds of pounds rather than tens of pounds. To meet the increased payload capacities demanded by present-day tasks, manipulator designers have turned once again to hydraulics as a means of actuation. In order to successfully design, build, and deploy a new hydraulic manipulator (or subsystem), sophisticated modeling, analysis, and control experiments are usually needed. Oak Ridge National Laboratory (ORNL) has a history of projects that incorporate hydraulics technology, including mobile robots, teleoperated manipulators, and full-scale construction equipment. In addition, to support the development and deployment of new hydraulic manipulators, ORNL has outfitted a significant experimental laboratory and has developed the software capability for research into hydraulic manipulators, hydraulic actuators, hydraulic systems, modeling of hydraulic systems, and hydraulic controls. The purpose of this article is to describe the past hydraulic manipulator developments and current hydraulic manipulator research capabilities at ORNL. Included are example experimental results from ORNL`s flexible/prismatic test stand.

Kress, R.L.; Jansen, J.F. [Oak Ridge National Lab., TN (United States); Love, L.J. [Oak Ridge Inst. for Science and Education, TN (United States)

1997-03-01

333

Effects of uncertainty, transmission type, driver age and gender on brake reaction and movement time  

Microsoft Academic Search

Problem: Braking time (BT) is a critical component in safe driving, and various approaches have been applied to minimize it. This study analyzed the components of BT in order to assess the effects of age, gender, vehicle transmission type, and event uncertainty, on its two primary components, perception-reaction time and brake-movement time. Method: Perception-reaction time and brake-movement time were measured

Lora Warshawsky-Livne; David Shinar

2002-01-01

334

Wear mechanism of disc-brake block material for new type of drilling rig  

Microsoft Academic Search

To improve friction and wear performance and service life of the disc-brake pair material of a drilling rig, a new type of\\u000a asbestos-free frictional material with better performance for disc-brake blocks is developed, and its wear mechanism is investigated\\u000a by friction and wear experiments. Topography and elementary components of the brake block’s wear surface are analyzed by employing\\u000a SEM and

Xinhua Wang; Simin Wang; Siwei Zhang; Deguo Wang

2008-01-01

335

Railway Noise Abatement: The Case for Retrofitting Freight Vehicles with Composite Brake Blocks  

Microsoft Academic Search

Basically rolling noise in railways is created by rough wheels and tracks. If both can be kept smooth, noise can be reduced\\u000a significantly. Smooth wheels can be achieved by replacing cast-iron brake-blocks with composite brake blocks. Currently two\\u000a types of composite brake blocks are being discussed: K- and LL-blocks. K-blocks probably have a higher noise reduction than\\u000a LL-blocks, but require

J. Oertli

336

Improvements for reduction of the brake squeal noise at Seoul metro rolling stock on tracks  

Microsoft Academic Search

Experimental and theoretical methods were applied to find and understand the phenomenon of brake squeal noise of the Seoul\\u000a Metro rolling stock on tracks. Generally, it is well known that brake squeal noise is strongly related to stick and slip between\\u000a brake pad and disk. In most cases for rolling stock on tracks, trailer cars needed more particular attention through

Seong Keol Kim

2009-01-01

337

Vibration and noise in brake systems of vehicles. Part 2: Theoretical investigation techniques  

Microsoft Academic Search

The paper reviews theoretical research into vibroacoustic phenomena in transport brake systems. The mechanisms of occurrence\\u000a of different types of noise and vibration in brakes are described. Analytical, numerical, and experiment-calculated methods\\u000a for studying brake noise are discussed and their disadvantages from the point of view of obtaining adequate calculation models\\u000a are analyzed. The results of prediction of the vibroacoustic

V. P. Sergienko; S. N. Bukharov

2009-01-01

338

Noise-related roughness on tread braked railway wheels-experimental measurements and numerical simulations  

Microsoft Academic Search

Block braking is studied experimentally and numerically with focus on the thermal phenomena, in particular on the development of localised temperature peaks: hot spots. Full-scale braking tests on an inertia dynamometer have been carried out. Block braking has also been simulated with two different FE-models, both being 2D-models, where one is based on time-averaging of the heat input to the

Martin Petersson; Tore Vernersson

2002-01-01

339

Computational Fluid Dynamics (CFD) investigation onto passenger car disk brake design  

NASA Astrophysics Data System (ADS)

The aim of this study is to investigate the flow and heat transfer in ventilated disc brakes using Computational Fluid Dynamics (CFD). NACA Series blade is designed for ventilated disc brake and the cooling characteristic is compared to the baseline design. The ventilated disc brakes are simulated using commercial CFD software FLUENTTM using simulation configuration that was obtained from experiment data. The NACA Series blade design shows improvements in Nusselt number compared to baseline design.

Munisamy, Kannan M.; Kanasan Moorthy, Shangkari K.

2013-06-01

340

Hydraulically actuated artificial muscles  

NASA Astrophysics Data System (ADS)

Hydraulic Artificial Muscles (HAMs) consisting of a polymer tube constrained by a nylon mesh are presented in this paper. Despite the actuation mechanism being similar to its popular counterpart, which are pneumatically actuated (PAM), HAMs have not been studied in depth. HAMs offer the advantage of compliance, large force to weight ratio, low maintenance, and low cost over traditional hydraulic cylinders. Muscle characterization for isometric and isobaric tests are discussed and compared to PAMs. A model incorporating the effect of mesh angle and friction have also been developed. In addition, differential swelling of the muscle on actuation has also been included in the model. An application of lab fabricated HAMs for a meso-scale robotic system is also presented.

Meller, M. A.; Tiwari, R.; Wajcs, K. B.; Moses, C.; Reveles, I.; Garcia, E.

2012-04-01

341

Hydraulic Arm Challenge  

NSDL National Science Digital Library

Students design and build a mechanical arm that lifts and moves an empty 12-ounce soda can using hydraulics for power. Small design teams (1-2 students each) design and build a single axis for use in the completed mechanical arm. One team designs and builds the grasping hand, another team the lifting arm, and a third team the rotation base. The three groups must work to communicate effectively through written and verbal communication and sketches.

Center for Engineering Educational Outreach,

342

Remotely Adjustable Hydraulic Pump  

NASA Technical Reports Server (NTRS)

Outlet pressure adjusted to match varying loads. Electrohydraulic servo has positioned sleeve in leftmost position, adjusting outlet pressure to maximum value. Sleeve in equilibrium position, with control land covering control port. For lowest pressure setting, sleeve shifted toward right by increased pressure on sleeve shoulder from servovalve. Pump used in aircraft and robots, where hydraulic actuators repeatedly turned on and off, changing pump load frequently and over wide range.

Kouns, H. H.; Gardner, L. D.

1987-01-01

343

Independent Orbiter Assessment (IOA): Analysis of the hydraulics/water spray boiler subsystem  

NASA Technical Reports Server (NTRS)

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA approach features a top-down analysis of the hardware to determine failure modes, criticality, and potential critical items (PCIs). To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. This report documents the independent analysis results for the Orbiter Hydraulics/Water Spray Boiler Subsystem. The hydraulic system provides hydraulic power to gimbal the main engines, actuate the main engine propellant control valves, move the aerodynamic flight control surfaces, lower the landing gear, apply wheel brakes, steer the nosewheel, and dampen the external tank (ET) separation. Each hydraulic system has an associated water spray boiler which is used to cool the hydraulic fluid and APU lubricating oil. The IOA analysis process utilized available HYD/WSB hardware drawings, schematics and documents for defining hardware assemblies, components, and hardware items. Each level of hardware was evaluated and analyzed for possible failure modes and effects. Criticality was assigned based upon the severity of the effect for each failure mode. Of the 430 failure modes analyzed, 166 were determined to be PCIs.

Duval, J. D.; Davidson, W. R.; Parkman, William E.

1986-01-01

344

A note on safety-relevant vibrations induced by brake squeal  

NASA Astrophysics Data System (ADS)

Brake squeal is mostly considered as a comfort problem only but there are cases in which self-excited vibrations of the brake system not only cause an audible noise but also result in safety-relevant failures of the system. In particular this can occur if lightweight design rims having very low damping are used. Considering the special conditions of lightweight design rims, a minimal model for safety-relevant self-excited vibrations of brake systems is presented. It is shown that most of the knowledge emanated from investigations of the comfort problem can be used to understand and avoid safety-relevant failures of the brake system.

Hochlenert, Daniel; Spelsberg-Korspeter, Gottfried; Hagedorn, Peter

2010-09-01

345

WHY DO THE BRAKING INDICES OF PULSARS SPAN A RANGE OF MORE THAN 100 MILLIONS?  

SciTech Connect

Here we report that the observed braking indices of the 366 pulsars in the sample of Hobbs et al. range from about -10{sup 8} to about +10{sup 8} and are significantly correlated with their characteristic ages. Using the model of magnetic field evolution we developed previously based on the same data, we derive an analytical expression for the braking index which agrees with all the observed statistical properties of the braking indices of the pulsars in the sample of Hobbs et al. Our model is, however, incompatible with the previous interpretation that magnetic field growth is responsible for the small values of braking indices (<3) observed for ''baby'' pulsars with characteristic ages of less than 2 Multiplication-Sign 10{sup 3} yr. We find that the ''instantaneous'' braking index of a pulsar may be different from the ''averaged'' braking index obtained from fitting the data over a certain time span. The close match between our model-predicted ''instantaneous'' braking indices and the observed ''averaged'' braking indices suggests that the time spans used previously are usually smaller than or comparable to their magnetic field oscillation periods. Our model can be tested with the existing data by calculating the braking index as a function of the time span for each pulsar. In doing so, one can obtain for each pulsar all the parameters in our magnetic field evolution model, and may be able to improve the sensitivity of using pulsars to detect gravitational waves.

Zhang Shuangnan; Xie Yi, E-mail: zhangsn@ihep.ac.cn [National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China)

2012-12-20

346

Modeling the pneumatic relay valve of an s-cam air brake  

E-print Network

. In the absence of proper maintenance, the vehicle may not be able to develop the total braking force needed to bring the vehicle to a safe stop [1]. Brake lining replacement, checking for leaks and adjustment of push rod stroke are some of the important... maintenance procedures that are to be followed [1] regularly. A lack of sufficient push rod stroke could cause a delay in brake application due to the time it takes for the extended travel needed for brake application. This could be very dangerous in emergency...

Vilayannur Natarajan, Shankar

2005-08-29

347

Real-Time Dynamic Brake Assessment Proof of Concept Final Report  

SciTech Connect

This proof-of-concept research was performed to explore the feasibility of using real-world braking data from commercial motor vehicles to make a diagnosis of brake condition similar to that of the performance-based brake tester (PBBT). This was done by determining the relationship between pressure and brake force (P-BF), compensating for the gross vehicle weight (GVW). The nature of this P-BF relationship (e.g., low braking force for a given brake application pressure) may indicate brake system problems. In order to determine the relationship between brake force and brake application pressure, a few key parameters of duty cycle information were collected. Because braking events are often brief, spanning only a few seconds, a sample rate of 10 Hz was needed. The algorithm under development required brake application pressure and speed (from which deceleration was calculated). Accurate weight estimation was also needed to properly derive the braking force from the deceleration. In order to ensure that braking force was the predominant factor in deceleration for the segments of data used in analysis, the data was screened for grade as well. Also, the analysis needed to be based on pressures above the crack pressure. The crack pressure is the pressure below which the individual brakes are not applied due the nature of the mechanical system. This value, which may vary somewhat from one wheel end to another, is approximately 10 psi. Therefore, only pressures 15 psi and above were used in the analysis. The Department of Energy s Medium Truck Duty Cycle research has indicated that under the real-world circumstances of the test vehicle brake pressures of up to approximately 30 psi can be expected. Several different types of data were collected during the testing task of this project. Constant-pressure stopping tests were conducted at several combinations of brake application pressure (15, 20, 25, and 30 psi), load conditions (moderately and fully laden), and speeds (20 and 30 mph). Data was collected at 10 Hz. Standard and stepped-pressure performance-based brake tests with brake pressure transducers were performed for each loading condition. The stepped-pressure test included the constant-pressure intervals of brake application at 15, 20, 25, and 30 psi. The PBBT data files included 10 Hz streaming data collected during the testing of each axle. Two weeks of real-world duty cycle (driving and braking) data was also collected at 10 Hz. Initial analysis of the data revealed that the data collected in the field (i.e., day-to-day operations) provided the same information as that obtained from the controlled tests. Analysis of the data collected revealed a strong linear relationship between brake application pressure and deceleration for given GVWs. As anticipated, initial speed was not found to be a significant factor in the deceleration-pressure relationship, unlike GVW. The positive results obtained from this proof of concept test point to the need for further research to expand this concept. A second phase should include testing over a wider range of speeds and include medium brake application pressures in addition to the low pressures tested in this research. Testing on multiple vehicles would also be of value. This future phase should involve testing to determine how degradation of braking performance affects the pressure-deceleration relationship.

Lascurain, Mary Beth [ORNL; Franzese, Oscar [ORNL; Capps, Gary J [ORNL

2011-11-01

348

Analytica Chimica Acta 504 (2004) 199207 Arsenic speciation in Chinese brake fern by ion-pair high-performance  

E-print Network

) and arsenate [As(V)] in Chinese brake fern (Pteris vittata L.). The separation was performed on a reverse diameter is needed to connect the HPLC column to the ICP-MS nebulizer. Chinese brake fern (Pteris vittata L

Ma, Lena

349

66 FR 4104 - Brake System Safety Standards for Freight and Other Non-Passenger Trains and Equipment; End-of...  

Federal Register 2010, 2011, 2012, 2013

...automatic brake valve handle is moved...locomotive air compressor and the main...would include all compressors, piping, hoses, valves, and any other...handle of brake valve kept in the prescribed...position, and air compressors kept...

2001-01-17

350

Tachyon cosmology, supernovae data, and the big brake singularity  

SciTech Connect

We compare the existing observational data on type Ia supernovae with the evolutions of the Universe predicted by a one-parameter family of tachyon models which we have introduced recently [Phys. Rev. D 69, 123512 (2004)]. Among the set of the trajectories of the model which are compatible with the data there is a consistent subset for which the Universe ends up in a new type of soft cosmological singularity dubbed big brake. This opens up yet another scenario for the future history of the Universe besides the one predicted by the standard {lambda}CDM model.

Keresztes, Z.; Gergely, L. A.; Gorini, V.; Moschella, U.; Kamenshchik, A. Yu. [Department of Theoretical Physics, University of Szeged, Tisza Lajos krt 84-86, Szeged 6720 (Hungary); Department of Experimental Physics, University of Szeged, Dom Ter 9, Szeged 6720 (Hungary); Department of Theoretical Physics, University of Szeged, Tisza Lajos krt 84-86, Szeged 6720 (Hungary); Department of Experimental Physics, University of Szeged, Dom Ter 9, Szeged 6720 (Hungary); Department of Applied Science, London South Bank University, 103 Borough Road, London SE1 OAA (United Kingdom); Dipartimento di Scienze Fisiche e Mathematiche, Universita dell'Insubria, Via Valleggio 11, 22100 Como (Italy); INFN, sezione di Milano, Via Celoria 16, 20133 Milano (Italy); Dipartimento di Fisica and INFN, via Irnerio 46, 40126 Bologna (Italy); L. D. Landau Institute for Theoretical Physics, Russian Academy of Sciences, Kosygin street 2, 119334 Moscow (Russian Federation)

2009-04-15

351

Tachyon cosmology, supernovae data and the Big Brake singularity  

E-print Network

We compare the existing observational data on type Ia Supernovae with the evolutions of the universe predicted by a one-parameter family of tachyon models which we have introduced recently in paper \\cite{we-tach}. Among the set of the trajectories of the model which are compatible with the data there is a consistent subset for which the universe ends up in a new type of soft cosmological singularity dubbed Big Brake. This opens up yet another scenario for the future history of the universe besides the one predicted by the standard $\\Lambda$CDM model.

Z. Keresztes; L. Á. Gergely; V. Gorini; U. Moschella; A. Yu. Kamenshchik

2009-04-21

352

Calculator programs determine drilling hydraulics  

SciTech Connect

Two TI-59 programs were prepared for the calculation of drilling hydraulics as set forth in the Hughes Tool Co. publication, Practical Hydraulics. One presents the stepwise determination of drill string pressure drop while the second, to be published in a future issue, calculates jet area, jet velocity and impact force along with bit pressure drop and hydraulic horsepower. Another section of the second program considers pump mechanics, calculating the required strokes per minute to attain a specific circulating rate, or the circulation that would result from a specific pump speed. Hydraulic horsepower of the pump is then calculated from this rate and a maximum pump pressure.

Landry, W.E.

1987-05-01

353

Hydraulic mining method  

DOEpatents

A method of hydraulically mining an underground pitched mineral vein comprising drilling a vertical borehole through the earth's lithosphere into the vein and drilling a slant borehole along the footwall of the vein to intersect the vertical borehole. Material is removed from the mineral vein by directing a high pressure water jet thereagainst. The resulting slurry of mineral fragments and water flows along the slant borehole into the lower end of the vertical borehole from where it is pumped upwardly through the vertical borehole to the surface.

Huffman, Lester H. (Kent, WA); Knoke, Gerald S. (Kent, WA)

1985-08-20

354

Fluid Power/Basic Hydraulics. Instructor's Guide.  

ERIC Educational Resources Information Center

This guide is designed to assist industrial vocational instructors in teaching a course on fluid power and basic hydraulics. Covered in the unit on the basics of fluid power and hydraulics are the following topics: the fundamentals of fluid power and hydraulics, basic hydraulic circuits, and servicing a hydraulic jack. The second unit, consisting…

Stanbery, Richard

355

A Test of the Tau-Dot Hypothesis of Braking Control in the Real World  

ERIC Educational Resources Information Center

A controlled experiment used instrumented vehicles in a real-world driving task to compare D. N. Lee's (1976) tau-dot hypothesis of braking control with an alternative based on the direct estimation and control of ideal deceleration (T. Yates, M. Harris, & P. Rock, 2004). Drivers braked to stop as closely as possible to a visual target from…

Rock, Paul B.; Harris, Mike G.; Yates, Tim

2006-01-01

356

TRANSIENT ANALYSIS OF BRAKING MODE OPERATION OF INDUCTION MOTOR FED FROM A VARIABLE FREQUENCY SOURCE  

Microsoft Academic Search

The transient behaviour of a three phase induction motor in the braking mode is investigated when the motor is fed from a variable frequency source. Appropriate voltage and frequency conditions to ensure minimum stopping time for plugging as well as for the case when plugging is used in conjunction with regenerative braking are identified. A dynamic model has been developed

J. R. P. GUPTA; BHIM SINGH; S. S. MURTHY

1983-01-01

357

Vehicle dynamic stability improvements through gain-scheduled steering and braking control  

Microsoft Academic Search

This paper is concerned with the synthesis of a robust gain-scheduled ?? MIMO vehicle dynamic stability controller (VDSC) involving both steering and rear braking actuators. This VDSC aims at improving automotive vehicle yaw stability and lateral performances. The aim of this work is to provide a methodology to synthesise such a controller while taking into account the braking actuator limitations

C. Poussot-Vassal; O. Sename; L. Dugard; S. M. Savaresi

2011-01-01

358

Self-excited brake noise investigation using the technique of classical holographic interferometry  

Microsoft Academic Search

The development of a systematic, whole body, visual recording process and its application to the study of disc brake noise and its recent adaptation to investigate drum brake noise is discussed. It is demonstrated that amplitude and vibration phase information my be obtained using classical double pulsed holographic techniques. Additionally it is demonstrated that details of a moving mode of

J. D. Fieldhouse; T. P. Newcomb

1994-01-01

359

Friction and vibration of automotive brake pads containing different abrasive particles  

Microsoft Academic Search

Automotive brake friction materials with four different abrasive particles were investigated. The abrasives used in this study were commercial grade silicon carbide, zircon, quartz and magnesia. For microscopic understanding of friction and wear by abrasive particles in the brake friction material, single-particle scratch tests followed by scratch tests with multiple particles were performed first to understand the behavior of abrasive

Sung Soo Kim; Hee Jung Hwang; Min Wook Shin; Ho Jang

2011-01-01

360

Numerical Analysis of Disc Brake Squeal Considering Temperature Dependent Friction Coefficient  

Microsoft Academic Search

Passenger cars have become one of the main transportations for people travelling from one place to another. Indeed, vehicle quietness and passenger comfort issues are a major concern. One of vehicle components that occasionally generate unwanted vibration and unpleasant noise is the brake system. Brake squeal noise is the most troublesome and irritant one to both car passenger and the

A. R. AbuBakar; M. K. AbdulHamid; M. Mohamad; A. Dzakaria; B. AbdGhani

361

Noise and vibration in brake systems of vehicles. Part 1: Experimental procedures  

Microsoft Academic Search

The paper describes the vibroacoustic phenomena generated during frictional interaction of solid bodies. A classification\\u000a is given for brake-induced noise. Modern experimental methods for studying vibroacoustic phenomena in metal-polymer friction\\u000a contacts are analyzed. The main approaches to reducing noise and vibration in vehicle brakes are considered.

V. P. Sergienko; S. N. Bukharov; A. V. Kupreev

2008-01-01

362

Vehicle yaw control via coordinated use of steering/braking systems  

E-print Network

Vehicle yaw control via coordinated use of steering/braking systems M. Doumiati, O. Sename, J with steer- ing/braking coordination task for vehicle yaw control. For steerability enhancement, only active steering control is involved. However, when the vehicle reaches the handling limits, both steering

Paris-Sud XI, Université de

363

76 FR 44829 - Federal Motor Vehicle Safety Standards; Air Brake Systems  

Federal Register 2010, 2011, 2012, 2013

...the average brake application timing of 0.31 seconds that was measured on the steer axle. Second, the brake application timing was not particularly fast on the drive axles (0.41 and 0.42 seconds for the rear and intermediate drive axles...

2011-07-27

364

49 CFR 393.47 - Brake actuators, slack adjusters, linings/pads and drums/rotors.  

Code of Federal Regulations, 2010 CFR

...actuators must be less than 80 percent of the rated strokes listed in SAE J1817—Long Stroke Air Brake Actuator Marking, July 2001 (See...of this document), or 80 percent of the rated stroke marked on the brake chamber by the chamber...

2010-10-01

365

Arsenic accumulation by two brake ferns growing on an arsenic mine and their potential in phytoremediation  

Microsoft Academic Search

In an area near an arsenic mine in Hunan Province of south China, soils were often found with elevated arsenic levels. A field survey was conducted to determine arsenic accumulation in 8 Cretan brake ferns (Pteris cretica) and 16 Chinese brake ferns (Pteris vittata) growing on these soils. Three factors were evaluated: arsenic concentration in above ground parts (fronds), arsenic

Chao-Yang Wei; Tong-Bin Chen

2006-01-01

366

Calibration, Information, and Control Strategies for Braking to Avoid a Collision  

ERIC Educational Resources Information Center

This study explored visual control strategies for braking to avoid collision by manipulating information about speed of self-motion. Participants watched computer-generated displays and used a brake to stop at an object in the path of motion. Global optic flow rate and edge rate were manipulated by adjusting eyeheight and ground-texture size.…

Fajen, Brett R.

2005-01-01

367

Solid state circuit controls direction, speed, and braking of dc motor  

NASA Technical Reports Server (NTRS)

Full-wave bridge rectifier circuit controls the direction, speed, and braking of a dc motor. Gating in the circuit of Silicon Controlled Rectifiers /SCRS/ controls output polarity and braking is provided by an SCR that is gated to short circuit the reverse voltage generated by reversal of motor rotation.

Hanna, M. F.

1966-01-01

368

76 FR 34801 - Petition for Modification of Single Car Air Brake Test Procedures  

Federal Register 2010, 2011, 2012, 2013

...FRA-2010-0174] Petition for Modification of Single Car Air Brake Test Procedures In accordance...FRA) grant a modification of the single car air brake test procedures as prescribed...FRA-2010-0174. PATH operates a fleet of 25 flat cars in consist with revenue cars utilized...

2011-06-14

369

78 FR 44189 - Petition for Modification of Single Car Air Brake Test Procedures  

Federal Register 2010, 2011, 2012, 2013

...FRA-2013-0064] Petition for Modification of Single Car Air Brake Test Procedures In accordance...per 49 CFR 232.307 to modify the single car air brake test procedures located in AAR...System Tests for Freight Equipment-- Single Car Test, and required pursuant to 49 CFR...

2013-07-23

370

Arsenic species and leachability in the fronds of the hyperaccumulator Chinese brake (Pteris vittata L.)  

E-print Network

was to understand the speciation and leachability of arsenic in the fronds of Chinese brake (Pteris vittata LArsenic species and leachability in the fronds of the hyperaccumulator Chinese brake (Pteris vittata L.) Cong Tu1a , Lena Q. Maa, *, Weihua Zhangb , Yong Caib , Willie G. Harrisa a Soil and Water

Ma, Lena

371

Brake control system modification, augmentor Wing Jet STOL Research Airplane (AWJSRA)  

NASA Technical Reports Server (NTRS)

The braking system for a short takeoff aircraft is discussed and the deficiencies are described. The installation of a Boeing 727 aircraft brake system was made to correct the deficiencies. Tests of the modified system were conducted using an analog computer/hardware simulator. Actual performance tests were conducted and the characteristics of the system were satisfactory.

Amberg, R. L.; Arline, J. A.; Jenny, R. W.

1974-01-01

372

49 CFR 229.29 - Air brake system calibration, maintenance, and testing.  

Code of Federal Regulations, 2013 CFR

...the maintenance and testing required in this section...system maintenance and testing that is required on...and tested: brake cylinder relay valve portions...components include: all pneumatic components of the locomotive...brake maintenance and testing as described in...

2013-10-01

373

49 CFR 229.29 - Air brake system calibration, maintenance, and testing.  

Code of Federal Regulations, 2012 CFR

...the maintenance and testing required in this section...system maintenance and testing that is required on...and tested: brake cylinder relay valve portions...components include: all pneumatic components of the locomotive...brake maintenance and testing as described in...

2012-10-01

374

Investigation on hardness and impact resistance of automotive brake pad composed with rice husk dust  

NASA Astrophysics Data System (ADS)

In this study, hardness and impact resistance properties of automotive brake pad composed with rice husk dust (RHD) were documented. RHD was mixed with other metallic and synthetic ingredients of automotive brake pad. To obtain RHD, rice husk was ground and dried to 1 - 3% moisture content. The RHD was screened to obtain different dust sizes (80 and 100-mesh) before it was mixed with other materials at different percentages of composition (10 and 30%). The mixture was then pressed to produce brake pad. Rockwell hardness testing machine was used in hardness determination, while Izod impact testing machine was used in impact resistance determination. Hardness resistance of automotive brake pad mixed with 10% composition and 80-mesh size of RHD was significantly higher than 100-mesh. Hardness resistance of automotive brake pad mixed with 30% composition and 100-mesh size of RHD was slightly higher than 80 mesh. However, based on analysis, the difference was not significant. According to the result, hardness resistance of automotive brake pad mixed with 30% composition of RHD was higher than 10%. RHD has filled up the space and enhanced the micro structural behaviour of automotive brake pad. Impact resistance of automotive brake pad mixed with 10% composition and 80-mesh size of RHD was insignificantly higher than 100-mesh. Impact resistance of automotive brake pad mixed with 30% composition and 80-mesh size of RHD was significantly higher than 100 mesh. Large RHD size has increased the capability to resist high-rated impact loading. The impact energy was distributed over wider area for larger particle size. This factor has increased the impact resistance of automotive brake pad from large dust size. Impact resistance of automotive brake pad mixed with 80-mesh size and 30% composition of RHD was higher than 10%. In contrast, impact resistance of automotive brake pad mixed with 100-mesh size and 10% composition of RHD was higher than 30%. However, the difference was not significant. In comparison with commercial brake pad, automotive brake pad composed with RHD showed better hardness results.

Bahari, Shahril Anuar; Isa, Khairul Hafizee; Kassim, Masitah Abu; Mohamed, Zulkifli; Othman, Eliasidi Abu

2012-06-01

375

Elemental composition of current automotive braking materials and derived air emission factors  

NASA Astrophysics Data System (ADS)

Wear-related PM emissions are an important constituent of total PM emissions from road transport. Due to ongoing (further) exhaust emission reduction wear emissions may become the dominant PM source from road transport in the near future. The chemical composition of the wear emissions is crucial information to assess the potential health relevance of these PM emissions. Here we provide an elemental composition profile of brake wear emissions as used in the Netherlands in 2012. In total, 65 spent brake pads and 15 brake discs were collected in car maintenance shops from in-use personal cars vehicles and analyzed with XRF for their metal composition (Fe, Cu, Zn, Sn, Al, Si, Zr, Ti, Sb, Cr, Mo, Mn, V, Ni, Bi, W, P, Pb and Co). Since car, engine and safety regulations are not nationally determined but controlled by European legislation the resulting profiles will be representative for the European personal car fleet. The brake pads contained Fe and Cu as the dominant metals but their ratio varied considerably, other relatively important metals were Sn, Zn and Sb. Overall a rather robust picture emerged with Fe, Cu, Zn and Sn together making up about 80-90% of the metals present in brake pads. Because the XRF did not give information on the contents of other material such as carbon, oxygen and sulphur, a representative selection of 9 brake pads was further analyzed by ICP-MS and a carbon and sulphur analyzer. The brake pads contained about 50% of non-metal material (26% C, 3% S and the remainder mostly oxygen and some magnesium). Based on our measurements, the average brake pad profile contained 20% Fe, 10% Cu, 4% Zn and 3% Sn as the dominant metals. The brake discs consisted almost entirely of metal with iron being the dominant metal (>95%) and only traces of other metals (<1% for individual metals). Non-metal components in the discs were 2-3% Silicon and, according to literature, ?3% carbon. The robust ratio between Fe and Cu as found on kerbsides has been used to estimate the contribution of brake pads and brake discs to total brake wear. Based on this approach our hypothesis is that 70% of the brake wear originates from the discs and only 30% from the brake pads.

Hulskotte, J. H. J.; Roskam, G. D.; Denier van der Gon, H. A. C.

2014-12-01

376

Design of permanent magnet eddy current brake for a small scaled electromagnetic launch model  

NASA Astrophysics Data System (ADS)

A variable pole-pitch double-sided permanent magnet (PM) linear eddy current brake (LECB) is proposed for a small scaled electromagnetic launch model. A two-dimensional (2D) analytical steady state model is presented for the double-sided PM-LECB, and the expression for the braking force is derived. Based on the analytical model, the material and eddy current skin effect of the conducting plate are analyzed. Moreover, a variable pole-pitch double-sided PM-LECB is proposed for the effective braking of the moving plate. In addition, the braking force is predicted by finite element (FE) analysis, and the simulated results are in good agreement with the analytical model. Finally, a prototype is presented to test the braking profile for validation of the proposed design.

Zhou, Shigui; Yu, Haitao; Hu, Minqiang; Huang, Lei

2012-04-01

377

Journal home page: http://www.sciencedirect.com/science/journal/0022460X Stability analysis and -synthesis control of brake systems  

E-print Network

. This type of analysis was then introduced in the context of brake noise to predict the dynamic behaviour-synthesis control of brake systems Journal of Sound and Vibration, Volume 298, Issues 4-5, 22 December 2006, Pages 1073-1087 S. Lignon, J-J. Sinou and L. Jézéquel STABILITY ANALYSIS AND µ-SYNTHESIS CONTROL OF BRAKE

Boyer, Edmond

378

On the transient dynamics of a multi-degree-of-freedom friction oscillator: a new mechanism for disc brake noise  

Microsoft Academic Search

In this paper, we examine the dynamics of a simple model for a braking process. The 4dof model is designed to capture some of the dynamics of a set of brake pads halting a rotor. We find from our model that the motion of the system transverse to the direction of braking experiences a sharp change in excitation when the

N. M. Kinkaid; O. M. O’Reilly; P. Papadopoulos

2005-01-01

379

On the transient dynamics of a multi-degree-of-freedom friction oscillator: a new mechanism for disc brake noise  

Microsoft Academic Search

In this paper, we examine the dynamics of a simple model for a braking process. The 4 dof model is designed to capture some of the dynamics of a set of brake pads halting a rotor. We find from our model that the motion of the system transverse to the direction of braking experiences a sharp change in excitation when

N. M. Kinkaid; O. M. O'Reilly; P. Papadopoulos

2005-01-01

380

On The Use of Eddy Current Brakes as Tunable, Fast Turn-On Viscous Dampers For Haptic Rendering  

E-print Network

On The Use of Eddy Current Brakes as Tunable, Fast Turn-On Viscous Dampers For Haptic RenderingGill University, Montr´eal, Canada ABSTRACT We describe the use of eddy current brakes as fast turn-on, tunable, linear dampers for haptic rendering using a prototype haptic device outfitted with eddy current brakes

Hayward, Vincent

381

Observed tidal braking in the earth/moon/sun system  

NASA Technical Reports Server (NTRS)

The low degree and order terms in the spherical harmonic model of the tidal potential were observed through the perturbations which are induced on near-earth satellite orbital motions. Evaluations of tracking observations from 17 satellites and a GEM-T1 geopotential model were used in the tidal recovery which was made in the presence of over 600 long-wavelength coefficients from 32 major and minor tides. Wahr's earth tidal model was used as a basis for the recovery of the ocean tidal terms. Using this tidal model, the secular change in the moon's mean motion due to tidal dissipation was found to be -25.27 + or - 0.61 arcsec/century squared. The estimation of lunar acceleration agreed with that observed from lunar laser ranging techniques (-24.9 + or - 1.0 arcsec/century squared), with the corresponding tidal braking of earth's rotation being -5.98 + or - 0.22 x 10 to the minus 22 rad/second squared. If the nontidal braking of the earth due to the observed secular change in the earth's second zonal harmonic is considered, satellite techniques yield a total value of the secular change of the earth's rotation rate of -4.69 + or - 0.36 x 10 to the minus 22 rad/second squared.

Christodoulidis, D. C.; Smith, D. E.; Williamson, R. G.; Klosko, S. M.

1987-01-01

382

Characterization of the high-frequency squeal on a laboratory brake setup  

NASA Astrophysics Data System (ADS)

This paper presents an experimental investigation on high-frequency brake squeal noise conducted on an appropriately designed experimental rig, called laboratory brake. Brake squeal is one of the major issues in the design process of an automotive brake and the development of a robust procedure for a "squeal-free" design is still under investigation. The high-frequency squeal is the most frequent noise generated by automotive brakes and is characterized by a wavelength of the "squealing mode" comparable to the length of the brake pad. The proposed "laboratory brake" is a good compromise between simple test rigs, such as the beam-on-disc, and the experimental setups that use real brakes. The beam-on-disc setup is a useful tool to understand the mechanism leading to the instability, but it does not simulate appropriately a real brake. On the other hand, real brakes are too complex for fundamental investigation and for efficient modeling. The experimental analysis shows a strong correlation between the length of the pad, the dynamic behavior of the system, and the squealing deformed shape. Moreover, depending on the length of the pad compared with the wavelength of the disc mode, three different kind of squeal instability may occur during experiments: the sine mode squeal, the cosine mode squeal and the rotating squeal. The latter is characterized by nodal diameters rotating during a squeal cycle. A linear reduced model, able to reproduce the dynamic behavior of the experimental setup, is used to predict the squeal occurrence. However, such linear model is not able to predict the rotating squeal characteristic that seems to be caused by nonlinear interactions due to the contact between the disc and the caliper.

Giannini, Oliviero; Massi, Francesco

2008-02-01

383

Hydraulic and Habitat Suitability Analyses Technical Memorandum  

E-print Network

Appendix D Hydraulic and Habitat Suitability Analyses Technical Memorandum #12;COPYRIGHT DECEMBER Series 2 and Pond Series 3 Hydraulic and Habitat Suitability Analyses Prepared for Bureau of Reclamation HILL, INC. III Hydraulic and Habitat Suitability Analyses

384

14 CFR 25.1435 - Hydraulic systems.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 2010-01-01 false Hydraulic systems. 25.1435 Section 25...Miscellaneous Equipment § 25.1435 Hydraulic systems. (a) Element design. Each element of the hydraulic system must be designed...

2010-01-01

385

Switching sliding mode force tracking control of piezoelectric-hydraulic pump-based friction element actuation systems for automotive transmissions  

NASA Astrophysics Data System (ADS)

In this study, a nonlinear sliding-mode controller is designed for force tracking of a piezoelectric-hydraulic pump (PHP)-based actuation system, which is developed to replace the current electro-hydraulic actuation systems for automatic transmission (AT) friction elements, such as band brakes or clutches. By utilizing the PHP, one can eliminate the various hydraulic components (oil pump, regulating valve and control valve) in current ATs and achieve a simpler configuration with more efficient operation. With the derived governing equation of motion of the PHP-based actuation system integrated with the friction element (band brake), a switching control law is synthesized based on the sliding-mode theory. To evaluate the effectiveness of the proposed control law, its force tracking performance for the engagement of a friction element during an AT 1\\to 2 up-shift is examined experimentally. It is shown that one can successfully track the desired force trajectory for AT shift control with small tracking error. This study demonstrates the potential of the PHP as a new controllable actuation system for AT friction elements.

Kim, Gi-Woo; Wang, K. W.

2009-08-01

386

Hydraulic wellbore erosion while drilling  

Microsoft Academic Search

This article is the first to identify nozzle hydraulic effects in a field evaluation of hole erosion. Common practice normally identifies annular velocity as the culprit for excessive hole washout. But field tests in this article clearly identify excessive nozzle hydraulics as the cause for hole erosion. Both oil-based and water-based drilling fluids were used during the field test. The

B. Chemerinski; L. Robinson

1996-01-01

387

Hydraulics of open channel flow  

Microsoft Academic Search

``Hydraulics of Open Channel Flow'' provides a complete understanding of open channel flow phenomena, and clearly explains the methods for solving the theoretical equations that represent these phenomena. Researchers and practicing engineers in charge of design of hydraulics structures, generation of hydropower, and computation of pollutant diffusion in channels and lakes will find in this essential reference a wealth of

Sergio Montes

1998-01-01

388

Hydraulics. FOS: Fundamentals of Service.  

ERIC Educational Resources Information Center

This manual on hydraulics is one of a series of power mechanics texts and visual aids for training in the servicing of agricultural and industrial machinery. Focus is on oil hydraulics. Materials provide basic information and illustrations for use by vocational students and teachers as well as shop servicemen and laymen. The twelve chapters focus…

John Deere Co., Moline, IL.

389

Tractor Hydraulics. A Teaching Reference.  

ERIC Educational Resources Information Center

The manual was developed to help provide a better understanding of how and why hydraulic principles serve the purposes of weight reduction, increase of physical effort, and more precise control to machines of all types. The four components that are necessary to have a workable hydraulic system--a reservoir, a pump, a valve, and a motor (cylinder)…

American Association for Vocational Instructional Materials, Athens, GA.

390

Hydraulically actuated well shifting tool  

SciTech Connect

This patent describes a hydraulically actuated shifting tool for actuating a sliding member in a well tool. It comprises: a housing having a hydraulic fluid bore therein; shifting dog means positioned on the housing for movement away and toward the housing; locking dog means positioned on the housing for movement away and toward the body; shifting dog hydraulic actuating means in fluid communication with the bore for causing engagement of the shifting dogs with the sliding member; locking dog hydraulic actuating means in communication with the bore for causing engagement of the locking dogs with the locking means; and hydraulic shifting means in communication with the bore for causing relative movement between the shifting dog means and the locking dog means for shifting the sliding sleeve.

Roth, B.A.

1992-10-20

391

Monument Creek hydraulics project  

NSDL National Science Digital Library

Students are given some general questions (file "IntroQuestions_07.pdf") related to project design during the class session before the main project is handed out. They need to use their textbook and/or other class resources to attempt to answer these questions and to prepare to discuss them the next class session. These questions concern field reconstruction of flood hydraulics, specifically. of bankfull flow. At this next class session we discuss their answers to the preliminary questions. Students are then given the main project handout (Monument_Ck_Problem_07.pdf). This gives them the general questions to be answered in the project. After reading it, students brainstorm again as a class about how to go about answering the questions. Students then divide themselves into research of three. These teams will synthesize data together and ultimately write up the project together. Each team then sends one member to join members of other teams to do one of the three main aspects of the field or computer work (1) field identification of the bankfull channel and measurement of bankfull channel geometry, (2) field determination of modern channel roughness from modern stream hydraulics (Manning's n is back-calculated from present channel geometry and flow), (3) development of a flood-frequency curve for this reach of Monument Creek from USGS discharge data. These working groups (with one member from each research team) work initially independently in the field and subsequently doing calculations in the lab, or on the computer. Once each working group has completed what it can do on its own, these groups split up and each member of each group carries the groups results back to his/her research team, and explains to the other members of the research team what he/she has done to this point and what results he/she has for the team. The team then works to synthesize he results into an overall answer to the questions posed at the beginning of the lab (confusing enough for you?). Each research team then writes up the results, sometimes (as in 2007) as a lab write up, in other years in scientific paper format. Whether the project is turned in simply as a lab write up or as a scientific paper, students are always asked to assess sources of error and how they might affect the results. Key words: Fluvial geomorphology, fluvial hydraulics, bankfull discharge, flood-frequency analysis Designed for a geomorphology course

Leonard, Eric

392

Some Fundamental Mechanisms of Hydraulic Fracturing.  

E-print Network

??This dissertation focuses mainly on three topics: (1) mixed-mode branching and segmentation of hydraulic fractures in brittle materials, (2) hydraulic fracture propagation in particulate materials,… (more)

Wu, Ruiting

2006-01-01

393

Piezoelectric hydraulic pump performance  

NASA Astrophysics Data System (ADS)

A piezohydraulic pump making use of the step and repeat capability of piezoelectric actuators has been developed for actuation of aircraft control surfaces. The piezohydraulic pump utilizes a piezoelectric stack actuator to drive a piston in a cylinder. The cylinder is fitted with two check valves. On the compression stroke, oil is forced out of the cylinder. On the intake stroke, oil is drawn into the cylinder. The oil is used to drive a linear actuator. The actuator was driven at 7cm/sec with a 271N (61lb) blocking force. To achieve this, the piezoelectric stack actuator was driven at 60Hz with a switching power supply. The system utilizes an accumulator to eliminate cavitation. This work discusses piezohydraulic pumping theory, pump design, and pump performance. Consideration of pump performance includes the effects of varying accumulator pressure, hydraulic oil viscosity, and load imposed on the linear actuator.

Mauck, Lisa D.; Oates, William S.; Lynch, Christopher S.

2001-06-01

394

Ileal brake activation: macronutrient-specific effects on eating behavior?  

PubMed

Background:Activation of the ileal brake, by infusing lipid directly into the distal part of the small intestine, alters gastrointestinal (GI) motility and inhibits food intake. The ileal brake effect on eating behavior of the other macronutrients is currently unknown.Objective:The objective of this study was to investigate the effects of ileal infusion of sucrose and casein on food intake, release of GI peptides, gastric emptying rate and small-bowel transit time with safflower oil as positive control.Design:This randomized, single-blind, crossover study was performed in 13 healthy subjects (6 male; mean age 26.4±2.9 years; mean body mass index 22.8±0.4?kg?m(-2)) who were intubated with a naso-ileal catheter. Thirty minutes after the intake of a standardized breakfast, participants received an ileal infusion, containing control ((C) saline), safflower oil ((HL) 51.7?kcal), low-dose casein ((LP) 17.2?kcal) or high-dose casein ((HP) 51.7?kcal), low-dose sucrose ((LC) 17.2?kcal) and high-dose sucrose ((HC) 51.7?kcal), over a period of 90?min. Food intake was determined during an ad libitum meal. Visual analogue score questionnaires for hunger and satiety and blood samples were collected at regular intervals.Results:Ileal infusion of lipid, protein and carbohydrate resulted in a significant reduction in food intake compared with control (HL: 464.3±90.7?kcal, P<0.001; HP: 458.0±78.6?kcal, P<0.005; HC: 399.0±57.0?kcal, P<0.0001 vs control: 586.7±70.2?kcal, P<0.001, respectively). A reduction in energy intake was still apparent when the caloric amount of infused nutrients was added to the amount eaten during the ad libitum meal.Secretion of cholecystokinin and peptide YY but not of glucagon-like peptide-1 (7-36) was increased during ileal perfusion of fat, carbohydrates and protein. During ileal perfusion of all macronutrients, a delay in gastric emptying and intestinal transit was observed, but differences were not significant compared with control.Conclusion:Apart from lipids, also sucrose and casein reduce food intake on ileal infusion, thereby activating the ileal brake. In addition to food intake, also satiety and GI peptide secretion were affected.International Journal of Obesity advance online publication, 29 July 2014; doi:10.1038/ijo.2014.112. PMID:24957485

van Avesaat, M; Troost, F J; Ripken, D; Hendriks, H F; Masclee, A A M

2014-06-24

395

Frictional behavior of automotive brake materials under wet and dry conditions  

SciTech Connect

The purpose of this effort was to develop an improved understanding of the relationship between the structure and frictional behavior of materials in the disc brake/rotor interface with a view toward improving the performance of automotive disc brakes. The three tasks involved in this Cooperative Research and Development Agreement (CRADA) were as follows: Task 1. Investigation of Brake Pads and Rotors. Characterize surface features of worn brake pads and rotors, with special attention to the transfer film which forms on them during operation. Ford to supply specimens for examination and other supporting information. Task 2. Effects of Atmosphere and Repeated Applications on Brake Material Friction. Conduct pin-on-disk friction tests at ORNL under controlled moisture levels to determine effects of relative humidity on frictional behavior of brake pad and rotor materials. Conduct limited tests on the characteristics of friction under application of repeated contacts. Task 3. Comparison of Dynamometer Tests with Laboratory Friction Tests. Compare ORNL friction data with Ford dynamometer test data to establish the degree to which the simple bench tests can be useful in helping to understand frictional behavior in full-scale brake component tests. This final report summarizes work performed under this CRADA.

Blau, P.J.; Martin, R.L. [Oak Ridge National Lab., TN (United States); Weintraub, M.H.; Jang, Ho; Donlon, W. [Ford Motor Co., Dearborn, MI (United States)

1996-12-15

396

A method to model anticipatory postural control in driver braking events.  

PubMed

Human body models (HBMs) for vehicle occupant simulations have recently been extended with active muscles and postural control strategies. Feedback control has been used to model occupant responses to autonomous braking interventions. However, driver postural responses during driver initiated braking differ greatly from autonomous braking. In the present study, an anticipatory postural response was hypothesized, modelled in a whole-body HBM with feedback controlled muscles, and validated using existing volunteer data. The anticipatory response was modelled as a time dependent change in the reference value for the feedback controllers, which generates correcting moments to counteract the braking deceleration. The results showed that, in 11 m/s(2) driver braking simulations, including the anticipatory postural response reduced the peak forward displacement of the head by 100mm, of the shoulder by 30 mm, while the peak head flexion rotation was reduced by 18°. The HBM kinematic response was within a one standard deviation corridor of corresponding test data from volunteers performing maximum braking. It was concluded that the hypothesized anticipatory responses can be modelled by changing the reference positions of the individual joint feedback controllers that regulate muscle activation levels. The addition of anticipatory postural control muscle activations appears to explain the difference in occupant kinematics between driver and autonomous braking. This method of modelling postural reactions can be applied to the simulation of other driver voluntary actions, such as emergency avoidance by steering. PMID:25174533

Östh, Jonas; Eliasson, Erik; Happee, Riender; Brolin, Karin

2014-09-01

397

Time simulation of squeal phenomena in realistic brake G. Vermot des Roches1,2, E. Balmes1,2, T. Pasquet3, R. Lemaire3  

E-print Network

noises up to 120 dB in the brake vicinity, at low speed, low pressure braking cases which mostly happenTime simulation of squeal phenomena in realistic brake models G. Vermot des Roches1,2, E. Balmes1@sdtools.com balmes@sdtools.com 3 Bosch (Chassis Systems Brakes), 126, Rue de Stalingrad, 93700, Drancy, France

Paris-Sud XI, Université de

398

Influence of centrifuge brake on residual platelet count and routine coagulation tests in citrated plasma.  

PubMed

Sample centrifugation is an essential step in the coagulation laboratory, as clotting tests are typically performed on citrated platelet (PLT) poor plasma (PPP). Nevertheless, no clear indication has been provided as to whether centrifugation of specimens should be performed with the centrifuge brake set to on or off. Fifty consecutive sodium citrate anticoagulated samples were collected and divided into two aliquots. The former was centrifuged as for Clinical Laboratory Standards Institute (CLSI) guidelines with the centrifuge brake set to on, whereas the latter was centrifuged again as for CLSI guidelines, but with the brake set to off. In the PPP of all samples, a PLT count was performed, followed by the analysis of activated partial thromboplastin time (APTT), prothrombin time (PT) and fibrinogen (FBG). The PLT count after samples centrifugation was substantially reduced, either with centrifuge brake set to on or off (5?±?1 versus 3?±?1?×?10/l; P?=?0.009). The frequency of samples exceeding a PLT count less than 10?×?10/l was nearly double in samples centrifuged with the brake on than in those with the brake off (14 versus 8%; P?brake set to on (mean bias 0.2?s; P?brake set to on (mean bias 0.29?g/l; P?brake set to off for providing a better quality specimen. PMID:24389587

Daves, Massimo; Giacomuzzi, Katia; Tagnin, Enrico; Jani, Erika; Adcock Funk, Dorothy M; Favaloro, Emmanuel J; Lippi, Giuseppe

2014-04-01

399

Calculator programs determine drilling hydraulics  

SciTech Connect

This paper describes Hydraulics II, which is prepared for the calculation of bit hydraulics and pump performance on the TI-59 using a PC-100C printer. The operator is prompted for the required input data with a printed register number and an abbreviated title. Output is printed and labeled. As in Hydraulics I, three magnetic cards are required, two for the program and the third for the alphanumeric memory of the prompts and output labels. Lines 000 through 100 are the same in both of these programs. The alphanumerics are stored in registers 31 through 53. The machine is partitioned 479.59.

Landry, W.E.

1987-06-01

400

Electrokinetic high pressure hydraulic system  

DOEpatents

A compact high pressure hydraulic pump having no moving mechanical parts for converting electric potential to hydraulic force. The electrokinetic pump, which can generate hydraulic pressures greater than 2500 psi, can be employed to compress a fluid, either liquid or gas, and manipulate fluid flow. The pump is particularly useful for capillary-base systems. By combining the electrokinetic pump with a housing having chambers separated by a flexible member, fluid flow, including high pressure fluids, is controlled by the application of an electric potential, that can vary with time.

Paul, Phillip H. (Livermore, CA); Rakestraw, David J. (Fremont, CA)

2000-01-01

401

Noise and Vibration Modeling for Anti-Lock Brake Systems  

NASA Astrophysics Data System (ADS)

A new methodology is proposed for noise and vibration analysis for Anti-Lock Brake Systems (ABS). First, a correlation between noise and vibration measurement data and simulation results need to be established. This relationship allows the engineers to focus on modeling and simulation instead of noise and vibration testing. A comprehensive ABS model is derived for noise and vibration study. The model can be set up to do different types of simulations for noise and vibration analysis. If some data is available from actual testing, then the test data can be easily imported into the model as an input to replace the corresponding part in the model. It is especially useful when the design needs to be modified, or trade-off between ABS performance and noise and vibration is necessary. The model can greatly reduce the time to market for ABS products. It also makes system level optimization possible.

Zhan, Wei

402

Epithelial morphogenesis in embryos: asymmetries, motors and brakes.  

PubMed

Epithelial cells play a central role in many embryonic morphogenetic processes, during which they undergo highly coordinated cell shape changes. Here, we review some common principles that have recently emerged through genetic and cellular analyses performed mainly with invertebrate genetic models, focusing on morphogenetic processes involving epithelial sheets. All available data argue that myosin II is the main motor that induces cell shape changes during morphogenesis. We discuss the control of myosin II activity during epithelial morphogenesis, as well as the recently described involvement of microtubules in this process. Finally, we examine how forces unleashed by myosin II can be measured, how embryos use specific brakes to control molecular motors and the potential input of mechano-sensation in morphogenesis. PMID:18375008

Quintin, Sophie; Gally, Christelle; Labouesse, Michel

2008-05-01

403

Analytical model and finite element computation of braking torque in electromagnetic retarder  

NASA Astrophysics Data System (ADS)

An analytical model has been developed for analyzing the braking torque in electromagnetic retarder by flux tube and armature reaction method. The magnetic field distribution in air gap, the eddy current induced in the rotor and the braking torque are calculated by the developed model. Two-dimensional and three-dimensional finite element models for retarder have also been developed. Results from the analytical model are compared with those from finite element models. The validity of these three models is checked by the comparison of the theoretical predictions and the measurements from an experimental prototype. The influencing factors of braking torque have been studied.

Ye, Lezhi; Yang, Guangzhao; Li, Desheng

2014-12-01

404

Analytical model and finite element computation of braking torque in electromagnetic retarder  

NASA Astrophysics Data System (ADS)

An analytical model has been developed for analyzing the braking torque in electromagnetic retarder by flux tube and armature reaction method. The magnetic field distribution in air gap, the eddy current induced in the rotor and the braking torque are calculated by the developed model. Two-dimensional and three-dimensional finite element models for retarder have also been developed. Results from the analytical model are compared with those from finite element models. The validity of these three models is checked by the comparison of the theoretical predictions and the measurements from an experimental prototype. The influencing factors of braking torque have been studied.

Ye, Lezhi; Yang, Guangzhao; Li, Desheng

2014-11-01

405

Recover Power with Hydraulic Motors  

E-print Network

Anywhere liquid pressure is reduced across a throttling device, there is a potential application for a hydraulic power recovery motor (HPRM). Cost of power makes HPRM's attractive with recoveries as small as 25 hp on a continuous basis. When...

Brennan, J. R.

1982-01-01

406

Hydraulic Loaders in Forestry Operations  

Microsoft Academic Search

I Historical background:Development from horse-skidding, wire cranes to hydraulic loaders.II Application of hydraulic loaders In forestry:Description of the different existing forestry applications and characterisations of different types of loaders.III Forestry loaders versus materials handling cranes:Differences in design and use.IV What are the requirements for a timber loader?Importance of reach, capacity strength, weight, geometry, flexibility and safety aspects.V Prerequisites for producing

Peter B. L. Lindgren

1977-01-01

407

Indirect Adaptive Robust Control of Electro-Hydraulic Systems Driven by Single-Rod Hydraulic Actuator  

E-print Network

Indirect Adaptive Robust Control of Electro-Hydraulic Systems Driven by Single-Rod Hydraulic) of electro-hydraulic systems driven by single- rod hydraulic actuators. Unlike the tracking that the proposed IARC achieves good tracking performance and accurate parameter estimation. INTRODUCTION Electro-hydraulic

Yao, Bin

408

MERCURY EMISSIONS FROM BRAKE WEAR ASSOCIATED WITH ON-ROAD VEHICLES  

EPA Science Inventory

This paper will focus on brake wear emissions of mercury and trace metals collected from 16 in-use light-duty vehicles (14 gasoline and 2 diesel) on a chassis dynamometer over the course of urban drive cycles....

409

In situ observations of suprathermal ion acceleration in the near-Earth jet braking region  

NASA Astrophysics Data System (ADS)

Plasma jet fronts and braking regions are sites of substantial particle acceleration in planetary magnetospheres and are considered to play a major role in other distant environments such as the solar corona and astrophysical jets. Jet fronts are the boundaries separating ambient from jetting plasma (e.g. due to reconnection) while jet braking regions is where jets are eventually stopped/diverted. A number of recent in situ observations in the Earth's magnetotail have allowed studying in detail electron acceleration mechanisms at jet fronts/braking region therein. Yet, observations of suprathermal ion acceleration are scarce. Here we show Cluster spacecraft observations of suprathermal ions up to ~ 1 MeV (about 10 times the thermal energy) in the near-Earth jet braking region. Observations indicate that ions are trapped between large-scale oppositely-directed jets and accelerated therein by strong electric fields.

Retinò, Alessandro; Khotyaintsev, Yuri; Vaivads, Andris; Le Contel, Olivier; Fu, Huishan; Zieger, Bertalan; Elena, Kronberg

2014-05-01

410

49 CFR 236.502 - Automatic brake application, initiation by restrictive block conditions stopping distance in...  

Code of Federal Regulations, 2012 CFR

...REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Automatic Train Stop, Train Control...distance in advance. An automatic train-stop or train-control system shall operate to initiate an automatic brake application at...

2012-10-01

411

49 CFR 236.506 - Release of brakes after automatic application.  

Code of Federal Regulations, 2012 CFR

...AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Automatic Train Stop, Train Control and Cab Signal Systems Standards § 236.506 Release of brakes after automatic application. The...

2012-10-01

412

49 CFR 236.502 - Automatic brake application, initiation by restrictive block conditions stopping distance in...  

Code of Federal Regulations, 2011 CFR

...REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Automatic Train Stop, Train Control...distance in advance. An automatic train-stop or train-control system shall operate to initiate an automatic brake application at...

2011-10-01

413

49 CFR 236.503 - Automatic brake application; initiation when predetermined rate of speed exceeded.  

Code of Federal Regulations, 2012 CFR

...REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Automatic Train Stop, Train Control...rate of speed exceeded. An automatic train control system shall operate to initiate an automatic brake application when...

2012-10-01

414

49 CFR 236.503 - Automatic brake application; initiation when predetermined rate of speed exceeded.  

Code of Federal Regulations, 2011 CFR

...REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Automatic Train Stop, Train Control...rate of speed exceeded. An automatic train control system shall operate to initiate an automatic brake application when...

2011-10-01

415

49 CFR 236.503 - Automatic brake application; initiation when predetermined rate of speed exceeded.  

Code of Federal Regulations, 2013 CFR

...REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Automatic Train Stop, Train Control...rate of speed exceeded. An automatic train control system shall operate to initiate an automatic brake application when...

2013-10-01

416

49 CFR 236.502 - Automatic brake application, initiation by restrictive block conditions stopping distance in...  

Code of Federal Regulations, 2013 CFR

...REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Automatic Train Stop, Train Control...distance in advance. An automatic train-stop or train-control system shall operate to initiate an automatic brake application at...

2013-10-01

417

Thiol synthesis and arsenic hyperaccumulation in Pteris vittata (Chinese brake fern)  

E-print Network

in arsenic detoxification. Abstract Pteris vittata (Chinese brake fern) has potential for phytoremediation to be constitutive in nature as in zinc and cadmium hyperaccumulators Arabidopsis halleri and Thlaspi caerulescens

Ma, Lena

418

Design and control of a dual unidirectional brake hybrid actuation system for haptic devices.  

PubMed

Hybrid actuators combining brakes and motors have emerged as an efficient solution to achieve high performance in haptic devices. In this paper, an actuation approach using two unidirectional brakes and a DC motor is proposed. The brakes are coupled to overrunning clutches and can apply a torque in only one rotational direction. The associated control laws, that are independent of the virtual environment model, calculate the control gains in real time in order limit the energy and the stiffness delivered by the motor to ensure stability. The reference torque is respected using the combination of the motor and the brake. Finally, an user experiment has been performed to evaluate the influence of passive and active torque differences in the perception of elasticity. The proposed actuator has a torque range of 0.03 Nm to 5.5 Nm with a 17.75 kNm (-2) torque density. PMID:25122593

Rossa, Carlos; Lozada, Jose; Micaelli, Alain

2014-01-01

419

Calculations of braking force of electro-dynamical railway car retarder  

Microsoft Academic Search

The method and results of calculations of the braking force acting on a railway car have been considered. Recommendations\\u000a for calculating the design of an electrodynamic railway car retarder have been given.

V. A. Razmyslov; V. M. Kuz’min; A. V. Serikov

2008-01-01

420

Injection Timing Effects on Brake Fuel Conversion Efficiency and Engine System's Respones  

E-print Network

Societal concerns on combustion-based fuel consumption are ever-increasing. With respect to internal combustion engines, this translates to a need to increase brake fuel conversion efficiency (BFCE). Diesel engines are a relatively efficient...

McLean, James Elliott

2011-10-21

421

49 CFR 232.217 - Train brake tests conducted using yard air.  

Code of Federal Regulations, 2013 CFR

... 4 2013-10-01 2013-10-01 false Train brake tests conducted using yard air. 232...STANDARDS FOR FREIGHT AND OTHER NON-PASSENGER TRAINS AND EQUIPMENT; END-OF-TRAIN DEVICES Inspection and Testing Requirements...

2013-10-01

422

49 CFR 236.506 - Release of brakes after automatic application.  

Code of Federal Regulations, 2011 CFR

...INSTRUCTIONS GOVERNING THE INSTALLATION, INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Automatic Train Stop, Train Control and Cab Signal Systems Standards § 236.506 Release of brakes...

2011-10-01

423

49 CFR 232.209 - Class II brake tests-intermediate inspection.  

Code of Federal Regulations, 2010 CFR

...STANDARDS FOR FREIGHT AND OTHER NON-PASSENGER TRAINS AND EQUIPMENT; END-OF-TRAIN DEVICES Inspection and Testing Requirements...a location other than the initial terminal of a train, a Class II brake test shall be performed...

2010-10-01

424

49 CFR 232.211 - Class III brake tests-trainline continuity inspection.  

Code of Federal Regulations, 2012 CFR

...STANDARDS FOR FREIGHT AND OTHER NON-PASSENGER TRAINS AND EQUIPMENT; END-OF-TRAIN DEVICES Inspection and Testing Requirements...A Class III brake test shall be performed on a train by a qualified person, as defined in §...

2012-10-01

425

49 CFR 232.217 - Train brake tests conducted using yard air.  

Code of Federal Regulations, 2011 CFR

... 4 2011-10-01 2011-10-01 false Train brake tests conducted using yard air. 232...STANDARDS FOR FREIGHT AND OTHER NON-PASSENGER TRAINS AND EQUIPMENT; END-OF-TRAIN DEVICES Inspection and Testing Requirements...

2011-10-01

426

49 CFR 232.211 - Class III brake tests-trainline continuity inspection.  

Code of Federal Regulations, 2013 CFR

...STANDARDS FOR FREIGHT AND OTHER NON-PASSENGER TRAINS AND EQUIPMENT; END-OF-TRAIN DEVICES Inspection and Testing Requirements...A Class III brake test shall be performed on a train by a qualified person, as defined in §...

2013-10-01

427

49 CFR 236.506 - Release of brakes after automatic application.  

Code of Federal Regulations, 2013 CFR

...INSTRUCTIONS GOVERNING THE INSTALLATION, INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Automatic Train Stop, Train Control and Cab Signal Systems Standards § 236.506 Release of brakes...

2013-10-01

428

49 CFR 232.103 - General requirements for all train brake systems.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 false General requirements for all train brake systems. 232.103 Section 232.103...STANDARDS FOR FREIGHT AND OTHER NON-PASSENGER TRAINS AND EQUIPMENT; END-OF-TRAIN DEVICES General Requirements § 232.103...

2013-10-01

429

49 CFR 232.609 - Handling of defective equipment with ECP brake systems.  

Code of Federal Regulations, 2011 CFR

...STANDARDS FOR FREIGHT AND OTHER NON-PASSENGER TRAINS AND EQUIPMENT; END-OF-TRAIN DEVICES Electronically Controlled Pneumatic... (a) Ninety-five percent of the cars in a train operating in ECP brake mode shall have...

2011-10-01

430

49 CFR 232.609 - Handling of defective equipment with ECP brake systems.  

Code of Federal Regulations, 2013 CFR

...STANDARDS FOR FREIGHT AND OTHER NON-PASSENGER TRAINS AND EQUIPMENT; END-OF-TRAIN DEVICES Electronically Controlled Pneumatic... (a) Ninety-five percent of the cars in a train operating in ECP brake mode shall have...

2013-10-01

431

49 CFR 232.103 - General requirements for all train brake systems.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 false General requirements for all train brake systems. 232.103 Section 232.103...STANDARDS FOR FREIGHT AND OTHER NON-PASSENGER TRAINS AND EQUIPMENT; END-OF-TRAIN DEVICES General Requirements § 232.103...

2012-10-01

432

49 CFR 232.103 - General requirements for all train brake systems.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 false General requirements for all train brake systems. 232.103 Section 232.103...STANDARDS FOR FREIGHT AND OTHER NON-PASSENGER TRAINS AND EQUIPMENT; END-OF-TRAIN DEVICES General Requirements § 232.103...

2011-10-01

433

49 CFR 232.211 - Class III brake tests-trainline continuity inspection.  

Code of Federal Regulations, 2010 CFR

...STANDARDS FOR FREIGHT AND OTHER NON-PASSENGER TRAINS AND EQUIPMENT; END-OF-TRAIN DEVICES Inspection and Testing Requirements...A Class III brake test shall be performed on a train by a qualified person, as defined in §...

2010-10-01

434

49 CFR 232.217 - Train brake tests conducted using yard air.  

Code of Federal Regulations, 2010 CFR

... 4 2010-10-01 2010-10-01 false Train brake tests conducted using yard air. 232...STANDARDS FOR FREIGHT AND OTHER NON-PASSENGER TRAINS AND EQUIPMENT; END-OF-TRAIN DEVICES Inspection and Testing Requirements...

2010-10-01

435

49 CFR 232.217 - Train brake tests conducted using yard air.  

Code of Federal Regulations, 2012 CFR

... 4 2012-10-01 2012-10-01 false Train brake tests conducted using yard air. 232...STANDARDS FOR FREIGHT AND OTHER NON-PASSENGER TRAINS AND EQUIPMENT; END-OF-TRAIN DEVICES Inspection and Testing Requirements...

2012-10-01

436

49 CFR 232.609 - Handling of defective equipment with ECP brake systems.  

Code of Federal Regulations, 2012 CFR

...STANDARDS FOR FREIGHT AND OTHER NON-PASSENGER TRAINS AND EQUIPMENT; END-OF-TRAIN DEVICES Electronically Controlled Pneumatic... (a) Ninety-five percent of the cars in a train operating in ECP brake mode shall have...

2012-10-01

437

Evaluation of driver braking performance to an unexpected object in the roadway  

E-print Network

performance to an unexpected object, as well as for expected object conditions, to better quantify perception response times, braking distances, and deceleration characteristics for these two conditions. The effects of pavement conditions and different...

Picha, Dale Louis

1994-01-01

438

Robot Arm Control Using AN Electro-Rheological (er) Clutch-Brake Mechanism:. Model Validation  

Microsoft Academic Search

Robot arm positioning is an important factor in the robotic process. However, the robot manipulator experiences positioning inaccuracies. This positioning error is due to the dynamic inefficiencies of its actuator: DC servomotor. In a bid to resolve this actuator problem, an electro-rheological (ER) clutch-brake mechanism is employed. This clutch-brake mechanism can actuate and halt the motion of the robot arm.

K. P. Tan; R. Stanway; W. A. Bullough

2006-01-01

439

The Effect of Wear Groove on Vibration and Noise of Aircraft Brakes: Theoretical and Experimental Evidence  

Microsoft Academic Search

The goal of this paper is to delineate recent experimental evidence that the presence of conforming surface wear groove tends to stabilize the vibration and noise response of aircraft brakes. This finding is consistent with an earlier theoretical study in which the contact between Carbon-Carbon (C\\/C) composite brake disks were assumed to be visco-elastic and through this assumption it was

Kambiz Farhang; Soydan Ozcan; Peter Filip

440

Stability analysis of a new model for floating caliper disk brake  

Microsoft Academic Search

The customers' demand for ride comfort has led the automotive industries to look for the various ways to reduce and control the brake noise. Intensive research on brake squeal (high frequency noise between 1-12 kHz) has been carried out. A large variety of mathematical-mechanical models has been developed, studying various instability phenomena. The squeal is ascribed mainly to three reasons:

T. Jearsiripongkul; G. Chakraborty; P. Hagedorn

2002-01-01

441

Combined fast valving and braking resistor application to improve transient stability  

E-print Network

COMBINED FAST VALVING AND BRAKING RESISTOR APPLICATION TO IMPROVE TRANSIENT STABILITY A Thesis by Submitted to the Graduate College of' Texas A&M University in Partial fulfillment of the requirement for the degree of MASTER OF SCIENCE May... 1982 Major Subjecta Electrical Engineering COMBINED FAST VALVING AND BRAKING RESISTOR APPLICATION TO IMPROVE TRANSIENT STABILITY A Thesis by Approved as to style and content by& herman oY mm ee ad of' De tment Member May 1982 ABSTRACT...

Chen, Jen-Yeu Thomas

2012-06-07

442

A Multifunctional Self-calibrated Sensor For Brake Fluid Condition Monitoring  

Microsoft Academic Search

A multifunctional self-calibrated sensor is proposed for on-line monitoring of liquid level and water content of brake fluid using capacitive method. The sensor is characterized by self-calibration ability to influence factors including temperature, water content (to liquid level sensing) and variety of brake fluid without calibration arithmetic supported by database as in conventional intelligent sensor systems. By using mutual calibrated

Chuantong Wang; Katsunori Shida

2006-01-01

443

Design of a new MR brake mount system considering vertical and horizontal vibrations  

NASA Astrophysics Data System (ADS)

In this paper, a new type of magnetorheological fluid (MRF) mount is proposed. This design is based on the well-known of two modes of MRF such as flow mode and shear mode. These modes are applied in the design which includes two components: MR mount for controlling vertical vibrations, and MR brake for controlling horizontal vibrations. The structure of MR valve is applied in design mount part, while the disk type of structure is employed in design brake part. These structures contribute to the initial requirements such as small structure, high damping force and high braking force. The theoretical analysis for the design is undertaken followed by design optimization using ANSYS ADPL software. The objective functions are concentrated on maximal damping force for MR mount and maximum braking force for MR brake. As traditional design, rubber mount is used in the proposed design for suffering static loads. It has been shown through computer simulation that the initial requirements with high damping force and high braking force have been successfully achieved.

Do, Xuan Phu; Quoc Hung, Nguyen; Park, Joon Hee; Choi, Seung-Bok

2014-03-01

444

Design Considerations and Experimental Verification of a Rail Brake Armature Based on Linear Induction Motor Technology  

NASA Astrophysics Data System (ADS)

This paper describes the design considerations and experimental verification of an LIM rail brake armature. In order to generate power and maximize the braking force density despite the limited area between the armature and the rail and the limited space available for installation, we studied a design method that is suitable for designing an LIM rail brake armature; we considered adoption of a ring winding structure. To examine the validity of the proposed design method, we developed a prototype ring winding armature for the rail brakes and examined its electromagnetic characteristics in a dynamic test system with roller rigs. By repeating various tests, we confirmed that unnecessary magnetic field components, which were expected to be present under high speed running condition or when a ring winding armature was used, were not present. Further, the necessary magnetic field component and braking force attained the desired values. These studies have helped us to develop a basic design method that is suitable for designing the LIM rail brake armatures.

Sakamoto, Yasuaki; Kashiwagi, Takayuki; Hasegawa, Hitoshi; Sasakawa, Takashi; Fujii, Nobuo

445

[Discrimination of varieties of brake fluid using visual-near infrared spectra].  

PubMed

A new method was developed to fast discriminate brands of brake fluid by means of visual-near infrared spectroscopy. Five different brands of brake fluid were analyzed using a handheld near infrared spectrograph, manufactured by ASD Company, and 60 samples were gotten from each brand of brake fluid. The samples data were pretreated using average smoothing and standard normal variable method, and then analyzed using principal component analysis (PCA). A 2-dimensional plot was drawn based on the first and the second principal components, and the plot indicated that the clustering characteristic of different brake fluid is distinct. The foregoing 6 principal components were taken as input variable, and the band of brake fluid as output variable to build the discriminate model by stepwise discriminant analysis method. Two hundred twenty five samples selected randomly were used to create the model, and the rest 75 samples to verify the model. The result showed that the distinguishing rate was 94.67%, indicating that the method proposed in this paper has good performance in classification and discrimination. It provides a new way to fast discriminate different brands of brake fluid. PMID:18800708

Jiang, Lu-lu; Tan, Li-hong; Qiu, Zheng-jun; Lu, Jiang-feng; He, Yong

2008-06-01

446

Kinetic ceramics piezoelectric hydraulic pumps  

NASA Astrophysics Data System (ADS)

This paper discusses the development and testing of two Piezoelectrically driven Hydraulic Pumps (PHP2 & PHP3) utilizing low cost discrete multilayer piezoelectric actuators and low cost structural components. New valve technologies were developed utilizing reed and MEMS valves. Structural optimization was performed to decrease weight and volume. The PHP3 design extracts power from a PZT material with high efficiency despite impedance mismatch between the piezoelectric actuator and fluid by utilizing a hydraulic pendulum energy recovery technique. Hydraulic power of 168 watts can be developed with a pump mass of under 1lb. Flow rate of 2300 cc/min free flow has been demonstrated as well as output pressure greater than 200 bar in the stalled condition. The result of the effort is practical solid state conversion of electrical energy into a useable hydraulic source for actuation systems without having normal rotational wear components. The PHP2 pump was used to power the hydraulic primary flight controls in a RPV technology demonstrator flight tested in November 2006.

O'Neill, Conal; Burchfield, John

2007-04-01

447

Free-piston Stirling hydraulic engine and drive system for automobiles  

NASA Technical Reports Server (NTRS)

The calculated fuel economy for an automotive free piston Stirling hydraulic engine and drive system using a pneumatic accumulator with the fuel economy of both a conventional 1980 spark ignition engine in an X body class vehicle and the estimated fuel economy of a 1984 spark ignition vehicle system are compared. The results show that the free piston Stirling hydraulic system with a two speed transmission has a combined fuel economy nearly twice that of the 1980 spark ignition engine - 21.5 versus 10.9 km/liter (50.7 versus 25.6 mpg) under comparable conditions. The fuel economy improvement over the 1984 spark ignition engine was 81 percent. The fuel economy sensitivity of the Stirling hydraulic system to system weight, number of transmission shifts, accumulator pressure ratio and maximum pressure, auxiliary power requirements, braking energy recovery, and varying vehicle performance requirements are considered. An important finding is that a multispeed transmission is not required. The penalty for a single speed versus a two speed transmission is about a 12 percent drop in combined fuel economy to 19.0 km/liter (44.7 mpg). This is still a 60 percent improvement in combined fuel economy over the projected 1984 spark ignition vehicle.

Beremand, D. G.; Slaby, J. G.; Nussle, R. C.; Miao, D.

1982-01-01

448

A global strategy based on experiments and simulations for squeal prediction on industrial railway brakes  

NASA Astrophysics Data System (ADS)

This paper presents an overview of recent experimental and numerical investigations on industrial railway brakes. The goal of the present study is to discuss the relevance of the mechanical modeling strategy for squeal prediction. Specific experimental set-ups based on transient and controlled braking tests are designed for this purpose. Measurements are performed on it to investigate the dynamic behavior of TGV squeal noise and its squeal characterization through experiments. It will be demonstrated that it is possible to build consistent and efficient finite element models to simulate squeal events in TGV brake systems. The numerical strategy will be presented, including not only the modeling of the TGV brake system and the stability analysis, but also the transient nonlinear dynamic and computational process based on efficient reduced basis. This complete numerical strategy allows us to perform relevance squeal prediction on industrial railway brakes. This study comes within the scope of a research program AcouFren that is supported by ADEME (Agence De l'Environnement et de la Maîtrise de l'Energie) concerning the reduction of the squeal noise generated by high power railway disc brakes. experiments with an evolution of the rotational speed of the disc: these tests are called "transient braking tests" and correspond to real braking tests, experiments with a controlled steady rotational speed (i.e. dynamic fluctuations in rotational speed are not significant): these tests are called "controlled braking tests". In the present study, the Continuous Wavelet Transform (CWT) [20] is used to study the time-history responses of the TGV brake system. So, a brief basic theory of the wavelet analysis that transforms a signal into wavelets that are well localized both in frequency and time is presented in this part of the paper. Considering a function f(t), the associated Continuous Wavelet Transform (CWT) corresponds to a wavelet transform given by W(a,b)=?-?+?f(t)?a,b*(t) dt where ?(t)={1}/{?{a}}?({t-b}/{a}) where a and b define the scale parameter and the time translation factor, respectively. The asterisk ?a,b* indicates the complex conjugate of ? that are the daughter wavelets (i.e. the dilated and shifted versions of the "'mother"' wavelet ? that is continuous in both time and frequency). The mother wavelet must satisfy an admissibility criterion in order to get a stably invertible transform.

Sinou, J.-J.; Loyer, A.; Chiello, O.; Mogenier, G.; Lorang, X.; Cocheteux, F.; Bellaj, S.

2013-09-01

449

Method for directional hydraulic fracturing  

DOEpatents

A method for directional hydraulic fracturing using borehole seals to confine pressurized fluid in planar permeable regions, comprising: placing a sealant in the hole of a structure selected from geologic or cemented formations to fill the space between a permeable planar component and the geologic or cemented formation in the vicinity of the permeable planar component; making a hydraulic connection between the permeable planar component and a pump; permitting the sealant to cure and thereby provide both mechanical and hydraulic confinement to the permeable planar component; and pumping a fluid from the pump into the permeable planar component to internally pressurize the permeable planar component to initiate a fracture in the formation, the fracture being disposed in the same orientation as the permeable planar component.

Swanson, David E. (West St. Paul, MN); Daly, Daniel W. (Crystal, MN)

1994-01-01

450

Toxic effects of brake wear particles on epithelial lung cells in vitro  

PubMed Central

Background Fine particulate matter originating from traffic correlates with increased morbidity and mortality. An important source of traffic particles is brake wear of cars which contributes up to 20% of the total traffic emissions. The aim of this study was to evaluate potential toxicological effects of human epithelial lung cells exposed to freshly generated brake wear particles. Results An exposure box was mounted around a car's braking system. Lung cells cultured at the air-liquid interface were then exposed to particles emitted from two typical braking behaviours („full stop“ and „normal deceleration“). The particle size distribution as well as the brake emission components like metals and carbons was measured on-line, and the particles deposited on grids for transmission electron microscopy were counted. The tight junction arrangement was observed by laser scanning microscopy. Cellular responses were assessed by measurement of lactate dehydrogenase (cytotoxicity), by investigating the production of reactive oxidative species and the release of the pro-inflammatory mediator interleukin-8. The tight junction protein occludin density decreased significantly (p < 0.05) with increasing concentrations of metals on the particles (iron, copper and manganese, which were all strongly correlated with each other). Occludin was also negatively correlated with the intensity of reactive oxidative species. The concentrations of interleukin-8 were significantly correlated with increasing organic carbon concentrations. No correlation was observed between occludin and interleukin-8, nor between reactive oxidative species and interleukin-8. Conclusion These findings suggest that the metals on brake wear particles damage tight junctions with a mechanism involving oxidative stress. Brake wear particles also increase pro-inflammatory responses. However, this might be due to another mechanism than via oxidative stress. PMID:19930544

2009-01-01

451

Detection of braking intention in diverse situations during simulated driving based on EEG feature combination  

NASA Astrophysics Data System (ADS)

Objective. We developed a simulated driving environment for studying neural correlates of emergency braking in diversified driving situations. We further investigated to what extent these neural correlates can be used to detect a participant?s braking intention prior to the behavioral response. Approach. We measured electroencephalographic (EEG) and electromyographic signals during simulated driving. Fifteen participants drove a virtual vehicle and were exposed to several kinds of traffic situations in a simulator system, while EEG signals were measured. After that, we extracted characteristic features to categorize whether the driver intended to brake or not. Main results. Our system shows excellent detection performance in a broad range of possible emergency situations. In particular, we were able to distinguish three different kinds of emergency situations (sudden stop of a preceding vehicle, sudden cutting-in of a vehicle from the side and unexpected appearance of a pedestrian) from non-emergency (soft) braking situations, as well as from situations in which no braking was required, but the sensory stimulation was similar to stimulations inducing an emergency situation (e.g., the sudden stop of a vehicle on a neighboring lane). Significance. We proposed a novel feature combination comprising movement-related potentials such as the readiness potential, event-related desynchronization features besides the event-related potentials (ERP) features used in a previous study. The performance of predicting braking intention based on our proposed feature combination was superior compared to using only ERP features. Our study suggests that emergency situations are characterized by specific neural patterns of sensory perception and processing, as well as motor preparation and execution, which can be utilized by neurotechnology based braking assistance systems.

Kim, Il-Hwa; Kim, Jeong-Woo; Haufe, Stefan; Lee, Seong-Whan

2015-02-01

452

Electokinetic high pressure hydraulic system  

DOEpatents

A compact high pressure hydraulic system having no moving parts for converting electric potential to hydraulic force and for manipulating fluids. Electro-osmotic flow is used to provide a valve and means to compress a fluid or gas in a capillary-based system. By electro-osmotically moving an electrolyte between a first position opening communication between a fluid inlet and outlet and a second position closing communication between the fluid inlet and outlet the system can be configured as a valve. The system can also be used to generate forces as large as 2500 psi that can be used to compress a fluid, either a liquid or a gas.

Paul, Phillip H. (Livermore, CA); Rakestraw, David J. (Fremont, CA)

2000-01-01

453

Numerical simulation of hydraulic transients  

NASA Astrophysics Data System (ADS)

A numerical method suitable for the analysis of hydraulic transients in one-dimensional pipelines as well as some applications of the method are presented in this thesis. In the present method one-dimensional flow equations are solved in a characteristic form using a finite difference technique. A nonequilibrium two-phase flow model is used, which makes it possible to analyze the effect of vaporization. The motion of the pipe-wall, which is important in some types of hydraulic transients, can be taken into account approximately. The main application of the method has been the piping of nuclear reactors.

Siikonen, T.

454

An Experimental Investigation of the Effect of Propellers Used as Aerodynamic Brakes on Stability and Control  

NASA Technical Reports Server (NTRS)

Tests were made of a model representative of a single-engine tractor-type airplane for the purpose of determining the stability and control effects of a propeller used as an aerodynamic brake. The tests were made with single-and dual-rotation propellers to show the effect of type of propeller rotation, and with positive thrust to provide basic data with which to compare the effects of negative thrust. Four configurations of the model were used to give the effects of tilting the propeller thrust axis down 5 deg., raising the horizontal tail, and combining both tilt and raised tail. Results of the tests are reported herein. The effects of negative thrust were found to be significant. The longitudinal stability was increased because of the loss of wing lift and increase of the angle of attack of the tail. Directional stability and both longitudinal and directional control were decreased because of the reduced velocity at the tail. These effects are moderate for moderate braking but become pronounced with full-power braking, particularly at high values of lift coefficient. The effects of model configuration changes were small when compared with the over-all effects of negative-thrust operation; however, improved stability and control characteristics were exhibited by the model with the tilted thrust axis. Raising the horizontal tail improved the longitudinal characteristics, but was detrimental to directional characteristics. The use of dual-rotation propeller reduced the directional trim charges resulting from the braking operation. A prototype airplane was assumed and handling qualities were computed and analyzed for normal (positive thrust) and braking operation with full and partial power. The results of these analyses are presented for the longitudinal characteristics in steady and accelerated flight, and for the directional characteristics in high- and low-speed flight. It was found that by limiting the power output of the engine (assuming the constant-speed propeller will function in the range of blade angles required for negative thrust) the stability and control characteristics may be held within the limits required for safe operation. Braking with full power, particularly at low speeds, is dangerous, but braking with very small power output is satisfactory from the standpoint of control. The amount of braking produced with zero power output is equal to or better than that produced by conventional spoiler-type brakes.

Hanson, Frederick H

1945-01-01

455

23 CFR 650.111 - Location hydraulic studies.  

Code of Federal Regulations, 2010 CFR

... 2010-04-01 false Location hydraulic studies. 650.111 Section 650...STRUCTURES, AND HYDRAULICS Location and Hydraulic Design of Encroachments on Flood Plains § 650.111 Location hydraulic studies. (a) National...

2010-04-01

456

Hydraulic Properties of Unsaturated Soils  

Technology Transfer Automated Retrieval System (TEKTRAN)

Many agrophysical applications require knowledge of the hydraulic properties of unsaturated soils. These properties reflect the ability of a soil to retain or transmit water and its dissolved constituents. The objective of this work was to develop an entry for the Encyclopedia of Agrophysics that w...

457

Hydraulic straight hole drill collar  

Microsoft Academic Search

An improved drill collar for forming relatively straight holes in crooked hole type formations. One or more hydraulic drill collars are connected in series relationship within a drill string above a rotary bit at the point of tangency. Each drill collar includes at least one outwardly opening, longitudinally extending slot formed on the exterior thereof. The slot includes a back

Townson

1985-01-01

458

Introduction to Hydraulics. Instructor's Guide.  

ERIC Educational Resources Information Center

This instructor's guide on hydraulics is part of a series of individualized instructional materials. The guide is provided to help the instructor make certain that each student gets the most benefit possible from both the student's manual and what he/she does on the job. Notes for the instructor contain suggestions on how the student should use…

Texas Univ., Austin. Extension Instruction and Materials Center.

459

Introduction to Hydraulics. Student's Manual.  

ERIC Educational Resources Information Center

This manual on hydraulics is one of a series of individualized instructional materials for students. The manual is self-paced, but is designed to be used under the supervision of an instructor. The manual contains 10 assignments, each with all the information needed, a list of objectives that should be met, and exercise questions that can help in…

Texas Univ., Austin. Extension Instruction and Materials Center.

460

Thermal-Hydraulic-Analysis Program  

NASA Technical Reports Server (NTRS)

ELM computer program is simple computational tool for modeling steady-state thermal hydraulics of flows of propellants through fuel-element-coolant channels in nuclear thermal rockets. Evaluates various heat-transfer-coefficient and friction-factor correlations available for turbulent pipe flow with addition of heat. Comparisons possible within one program. Machine-independent program written in FORTRAN 77.

Walton, J. T.

1993-01-01

461

Advanced emergency braking controller design for pedestrian protection oriented automotive collision avoidance system.  

PubMed

Automotive collision avoidance system, which aims to enhance the active safety of the vehicle, has become a hot research topic in recent years. However, most of the current systems ignore the active protection of pedestrian and other vulnerable groups in the transportation system. An advanced emergency braking control system is studied by taking into account the pedestrians and the vehicles. Three typical braking scenarios are defined and the safety situations are assessed by comparing the current distance between the host vehicle and the obstacle with the critical braking distance. To reflect the nonlinear time-varying characteristics and control effect of the longitudinal dynamics, the vehicle longitudinal dynamics model is established in CarSim. Then the braking controller with the structure of upper and lower layers is designed based on sliding mode control and the single neuron PID control when confronting deceleration or emergency braking conditions. Cosimulations utilizing CarSim and Simulink are finally carried out on a CarSim intelligent vehicle model to explore the effectiveness of the proposed controller. Results display that the designed controller has a good response in preventing colliding with the front vehicle or pedestrian. PMID:25097870

Lie, Guo; Zejian, Ren; Pingshu, Ge; Jing, Chang

2014-01-01

462

The Effect of Residual Stress on the Distortion of Gray Iron Brake Disks  

NASA Astrophysics Data System (ADS)

Thermal distortion of gray iron brake disks due to residual stress and its effect on brake vibrations were studied. The residual stress of heat- and non-heat-treated gray iron disks was measured using neutron scattering. Dynamometer tests were performed to measure the friction force oscillation caused by the disk runout during brake applications. High-temperature tensile tests were carried out to find out possible plastic deformation due to residual stress during brake applications. The results showed that the average residual stress of the heat-treated disk (47.6 MPa) was lower than that of the non-heat-treated disk (99.6 MPa). Dynamometer tests at high temperatures (up to 600 °C) indicated that the residual stress pronounced the runout: the increase in disk runout after the tests for the non-heat-treated sample was more than twice that for the heat-treated sample. This difference correlated well with the neutron scattering results and the dimensional changes after a separate vacuum heat treatment. The high-temperature tensile tests showed severe reductions in yield strength at 600 °C, suggesting that disks produced with no stress relaxation could be deformed during severe braking.

Shin, M. W.; Jang, G. H.; Kim, J. K.; Kim, H. Y.; Jang, Ho

2013-04-01

463

Intelligent control for braking-induced longitudinal vibration responses of floating-type railway bridges  

NASA Astrophysics Data System (ADS)

This paper presents an intelligent control method and its engineering application in the control of braking-induced longitudinal vibration of floating-type railway bridges. Equations of motion for the controlled floating-type railway bridges have been established based on the analysis of the longitudinal vibration responses of floating-type railway bridges to train braking and axle-loads of moving trains. For engineering applications of the developed theory, a full-scale 500 kN smart magnetorheologic (MR) damper has been designed, fabricated and used to carry out experiments on the intelligent control of braking-induced longitudinal vibration. The procedure for using the developed intelligent method in conjunction with the full-scale 500 kN MR dampers has been proposed and used to control the longitudinal vibration responses of the deck of floating-type railway bridges induced by train braking and axle-loads of moving trains. This procedure has been applied to the longitudinal vibration control of the Tian Xingzhou highway and railway cable-stayed bridge over the Yangtze River in China. The simulated results have shown that the intelligent control system using the smart MR dampers can effectively control the longitudinal response of the floating-type railway bridge under excitations of braking and axle-loads of moving trains.

Qu, Wei-Lian; Qin, Shun-Quan; Tu, Jian-Weia; Liu, Jia; Zhou, Qiang; Cheng, Haibin; Pi, Yong-Lin

2009-12-01

464

Regenerative braking systems with torsional springs made of carbon nanotube yarn  

NASA Astrophysics Data System (ADS)

The demonstration of large stroke, high energy density and high power density torsional springs based on carbon nanotube (CNT) yarns is reported, as well as their application as an energy-storing actuator for regenerative braking systems. Originally untwisted CNT yarn is cyclically loaded and unloaded in torsion, with the maximum rotation angle increasing until failure. The maximum extractable energy density is measured to be as high as 6.13 kJ/kg. The tests also reveal structural reorganization and hysteresis in the torsional loading curves. A regenerative braking system is built to capture the kinetic energy of a wheel and store it as elastic energy in twisted CNT yarns. When the yam's twist is released, the stored energy reaccelerates the wheel. The measured energy and mean power densities of the CNT yarns in the simple regenerative braking system are up to 4.69 kJ/kg and 1.21 kW/kg, respectively. A slightly lower energy density of up to 1.23 kJ/kg and a 0.29 kW/kg mean power density are measured for the CNT yarns in a more complex system that mimics a unidirectional rotating regenerative braking mechanism. The lower energy densities for CNT yarns in the regenerative braking systems as compared with the yarns themselves reflect the frictional losses of the regenerative systems.

Liu, S.; Martin, C.; Lashmore, D.; Schauer, M.; Livermore, C.

2014-11-01

465

Advanced Emergency Braking Controller Design for Pedestrian Protection Oriented Automotive Collision Avoidance System  

PubMed Central

Automotive collision avoidance system, which aims to enhance the active safety of the vehicle, has become a hot research topic in recent years. However, most of the current systems ignore the active protection of pedestrian and other vulnerable groups in the transportation system. An advanced emergency braking control system is studied by taking into account the pedestrians and the vehicles. Three typical braking scenarios are defined and the safety situations are assessed by comparing the current distance between the host vehicle and the obstacle with the critical braking distance. To reflect the nonlinear time-varying characteristics and control effect of the longitudinal dynamics, the vehicle longitudinal dynamics model is established in CarSim. Then the braking controller with the structure of upper and lower layers is designed based on sliding mode control and the single neuron PID control when confronting deceleration or emergency braking conditions. Cosimulations utilizing CarSim and Simulink are finally carried out on a CarSim intelligent vehicle model to explore the effectiveness of the proposed controller. Results display that the designed controller has a good response in preventing colliding with the front vehicle or pedestrian. PMID:25097870

Lie, Guo; Zejian, Ren; Pingshu, Ge; Jing, Chang

2014-01-01

466

Brake Failure from Residual Magnetism in the Mars Exploration Rover Lander Petal Actuator  

NASA Technical Reports Server (NTRS)

In January 2004, two Mars Exploration Rover spacecraft arrived at Mars. Each safely delivered an identical rover to the Martian surface in a tetrahedral lander encased in airbags. Upon landing, the airbags deflated and three Lander Petal Actuators opened the three deployable Lander side petals enabling the rover to exit the Lander. Approximately nine weeks prior to the scheduled launch of the first spacecraft, one of these mission-critical Lander Petal Actuators exhibited a brake stuck-open failure during its final flight stow at Kennedy Space Center. Residual magnetism was the definitive conclusion from the failure investigation. Although residual magnetism was recognized as an issue in the design, the lack of an appropriately specified lower bound on brake drop-out voltage inhibited the discovery of this problem earlier in the program. In addition, the brakes had more unit-to-unit variation in drop-out voltage than expected, likely due to a larger than expected variation in the magnetic properties of the 15-5 PH stainless steel brake plates. Failure analysis and subsequent rework of two other Lander Petal Actuators with marginal brakes was completed in three weeks, causing no impact to the launch date.

Jandura, Louise

2004-01-01

467

Ensemble smoother assimilation of hydraulic head and return flow data to estimate hydraulic conductivity distribution  

E-print Network

Ensemble smoother assimilation of hydraulic head and return flow data to estimate hydraulic and data measurements, an ensemble smoother (ES) to provide enhanced estimates of aquifer hydraulic conductivity (K) through assimilation of hydraulic head (H) and groundwater return flow volume (RFV

Bau, Domenico A.

468

Hydraulic conductivity imaging from 3-D transient hydraulic tomography at several pumping/observation densities  

E-print Network

Hydraulic conductivity imaging from 3-D transient hydraulic tomography at several pumping August 2013; accepted 7 September 2013; published 13 November 2013. [1] 3-D Hydraulic tomography (3-D HT (primarily hydraulic conductivity, K) is estimated by joint inversion of head change data from multiple

Barrash, Warren

469

A study on the position control of hydraulic cylinder driven by hydraulic transformer using disturbance observer  

Microsoft Academic Search

A hydraulic cylinder drive using a hydraulic transformer, which is considered as secondary controlled unit, is studied here. Using hydraulic transformer for driving a hydraulic cylinder should avoid energy loss via controlled valves and get benefit from recovery of the load potential. Position control, an important issue of the cylinder control is investigated in this paper. To obtain robust position

Ho Triet Hung; Ahn Kyoung Kwan

2008-01-01

470

Hydraulic characterization of " Furcraea andina  

NASA Astrophysics Data System (ADS)

The present level of pollution, increasingly involving groundwaters, constitutes a serious risk for environment and human health. Therefore the remediation of saturated and unsaturated soils, removing pollutant materials through innovative and economic bio-remediation techniques is more frequently required. Recent studies on natural fiber development have shown the effectiveness of these fibers for removal of some heavy metals, due to the lignin content in the natural fibers which plays an important role in the adsorption of metal cations (Lee et al., 2004; Troisi et al., 2008; C. Fallico, 2010). In the context of remediation techniques for unsaturated and/or saturated zone, an experimental approach for the hydraulic characterization of the "Furcraea andina" (i.e., Cabuya Blanca) fiber was carried out. This fiber is native to Andean regions and grows easily in wild or cultivated form in the valleys and hillsides of Colombia, Ecuador, and Peru. Fibers of "Furcraea andina" were characterized by experimental tests to determine their hydraulic conductivity or permeability and porosity in order to use this medium for bioremediation of contaminated aquifer exploiting the physical, chemical and microbial capacity of natural fiber in heavy metal adsorption. To evaluate empirically the hydraulic conductivity, laboratory tests were carried out at constant head specifically on the fibers manually extracted. For these tests we used a flow cell (used as permeameter), containing the "Furcraea andina" fibers to be characterized, suitably connected by a tygon pipe to a Marriott's bottle, which had a plastic tube that allow the adjustment of the hydraulic head for different tests to a constant value. By this experiment it was also possible to identify relationships that enable the estimation of permeability as a function of density, i.e. of the compaction degree of the fibers. Our study was carried out for three values of hydraulic head (H), namely 10, 18, and 25 cm and for each constant head we repeated the test for three different rate of fiber compaction within the flow cell, corresponding to three different densities (146 kg/m3, 200 kg/m3 and 240 kg/m3). We observed that with increasing density of the fibers there is an increase of hydraulic conductivity. The importance of the experimental results on permeability acquires greater relevance when compared to the values of hydraulic conductivity already known from the literature for different soils types. In this study, special attention has been given to the value of hydraulic conductivity of this fiber, considering that in the framework of groundwater remediation strategies if the hydraulic conductivity in the barrier is lower than that of the surrounding aquifer, the plume may change its natural pathway, bypassing the barrier and veering towards larger hydraulic conductivity. Reference • Lee, B. G. and Rowell, R. M.: Removal of heavy metal ions from aqueous solutions using lignocellulosic fibers, J. Natural Fibers, 1, 97-108, 2004. • Troisi, S., Fallico, C., Straface, S., and Mazzuca, L.: Biodreni per la bonifica di siti contaminati realizzati con fibre naturali liberiane ad elevato sviluppo superficiale. Brevetto dell'Università della Calabria (n.: CS2008A00018), 2008. • C. Fallico, S. Troisi, A. Molinari, and M. F. Rivera.: Characterization of broom fibers for PRB in the remediation of aquifers contaminated by heavy metals, Biogeosciences journal , 7, 2545-2556, 2010

Rivera-Velasquez, M. F.; Fallico, C.; Molinari, A.; Santillan, P.; Salazar, M.

2012-04-01

471

Driving and braking control of PM synchronous motor based on low-resolution hall sensor for battery electric vehicle  

NASA Astrophysics Data System (ADS)

Resolvers are normally employed for rotor positioning in motors for electric vehicles, but resolvers are expensive and vulnerable to vibrations. Hall sensors have the advantages of low cost and high reliability, but the positioning accuracy is low. Motors with Hall sensors are typically controlled by six-step commutation algorithm, which brings high torque ripple. This paper studies the high-performance driving and braking control of the in-wheel permanent magnetic synchronous motor (PMSM) based on low-resolution Hall sensors. Field oriented control (FOC) based on Hall-effect sensors is developed to reduce the torque ripple. The positioning accuracy of the Hall sensors is improved by interpolation between two consecutive Hall signals using the estimated motor speed. The position error from the misalignment of the Hall sensors is compensated by the precise calibration of Hall transition timing. The braking control algorithms based on six-step commutation and FOC are studied. Two variants of the six-step commutation braking control, namely, half-bridge commutation and full-bridge commutation, are discussed and compared, which shows that the full-bridge commutation could better explore the potential of the back electro-motive forces (EMF), thus can deliver higher efficiency and smaller current ripple. The FOC braking is analyzed with the phasor diagrams. At a given motor speed, the motor turns from the regenerative braking mode into the plug braking mode if the braking torque exceeds a certain limit, which is proportional to the motor speed. Tests in the dynamometer show that a smooth control could be realized by FOC driving control and the highest efficiency and the smallest current ripple could be achieved by FOC braking control, compared to six-step commutation braking control. Therefore, FOC braking is selected as the braking control algorithm for electric vehicles. The proposed research ensures a good motor control performance while maintaining low cost and high reliability.

Gu, Jing; Ouyang, Minggao; Li, Jianqiu; Lu, Dongbin; Fang, Chuan; Ma, Yan

2013-01-01

472

The hydraulic conductivity of chopped sorghum  

SciTech Connect

Hydraulic conductivity of water through chopped sweet sorghum at various packing densities and soaking times was measured using permeameters. Hydraulic conductivity decreased by two orders of magnitude as packing density increased from 400 to 897 kg/m/sup 3/. Soaking time had less effect on hydraulic conductivity, and the effect depended on packing density.

Custer, M.H.; Reddell, D.L.; Sweeten, J.M.

1987-01-01

473

Regulation of Hydraulic Fracturing in California  

E-print Network

APRIL 2013 Regulation of Hydraulic Fracturing in California: A WAsteWAteR And WAteR QuAlity Pe | Regulation of Hydraulic Fracturing in California Wheeler Institute for Water Law & Policy Center for Law #12;Regulation of Hydraulic Fracturing in California | 3Berkeley law | wheeler InstItute for water law

Kammen, Daniel M.

474

4, 37193769, 2007 A model for hydraulic  

E-print Network

HESSD 4, 3719­3769, 2007 A model for hydraulic redistribution G. G. Amenu and P. Kumar Title Page are under open-access review for the journal Hydrology and Earth System Sciences A model for hydraulic;HESSD 4, 3719­3769, 2007 A model for hydraulic redistribution G. G. Amenu and P. Kumar Title Page

Paris-Sud XI, Université de

475

Numerical Study of a Turbulent Hydraulic Jump  

E-print Network

Numerical Study of a Turbulent Hydraulic Jump Qun Zhao, Shubhra Misra, Ib. A. Svendsen and James T of a Turbulent Hydraulic Jump ­ p.1/14 #12;Objective Our ultimate goal is to study the breaking waves. Numerical Study of a Turbulent Hydraulic Jump ­ p.2/14 #12;A moving bore Qiantang Bore China (Courtesy of Dr J

Zhao, Qun

476

LA-12968-MS The Unsaturated Hydraulic  

E-print Network

LA-12968-MS The Unsaturated Hydraulic Characteristics of the BandelierTuff LosN A T I O N A L L A B technical correctness. #12;The Unsaturated Hydraulic Characteristics of the Bandelier Tuff David B. Rogers........................................................................................................4 Hydraulic Data Presentation

477

Hydraulic Cooling Tower Driver- The Innovation  

E-print Network

-drive eliminates these items from the drive train and puts the same electric motor HP at ground level close coupled to a hydraulic pump, filters, and oil reservoir. Hydraulic lines bring oil pressure to the hydraulic motor, which is more than 75% less weight than...

Dickerson, J. A.

478

Hydraulic Fracture: multiscale processes and moving  

E-print Network

Hydraulic Fracture: multiscale processes and moving interfaces Anthony Peirce Department Mitchell (UBC) · Ed Siebrits (SLB, Houston) #12;2 Outline · What is a hydraulic fracture? · Scaling Fluid Proppant #12;6 An actual hydraulic fracture #12;7 HF experiment (Jeffrey et al CSIRO) #12;8 1D

Peirce, Anthony

479

Hydraulic Fracture: multiscale processes and moving  

E-print Network

Hydraulic Fracture: multiscale processes and moving interfaces Anthony Peirce Department Siebrits (SLB, Houston) #12;2 Outline · What is a hydraulic fracture? · Mathematical models of hydraulic fracture · Scaling and special solutions for 1-2D models · Numerical modeling for 2-3D problems

Peirce, Anthony

480

Hydraulic Fracturing in Michigan Integrated Assessment  

E-print Network

Hydraulic Fracturing in Michigan Integrated Assessment #12;Agenda · Welcome and introduction and timeline · Panel presentation and discussion · Facilitated Q & A · Closing remarks #12;Hydraulic Fracturing · Leverages resources IA BENEFITS Benefits of Integrated Assessment #12;Key Points: · Hydraulic Fracturing (HF

Kamat, Vineet R.

481

Optimize Bit Hydraulics for Minimum Cost Drilling  

Microsoft Academic Search

In a previous paper, the authors derived a condition for optimum bit hydraulics considering increases in rate of penetration (ROP), fuel costs and pump maintenance costs with increased bit hydraulics. This paper is an extension of the previous work and demonstrates practical application of the new hydraulics optimization method. Previously unpublished full scale laboratory drilling data obtained by the authors

H. H. Doiron; J. D. Deane

1983-01-01

482

Nonlinear Control of a Hydraulic Parallel Manipulator  

Microsoft Academic Search

An adaptive nonlinear controller is proposed for position tracking in hydraulic robots by adopting the backstepping methodology. Full system models including rigid body and hydraulic dynamics are incorporated in the design. The tracking errors are shown to be asymptotically stable in the presence of parametric uncertainties using Lyapunov analysis. The controller is applied to a Stewart type hydraulic manipulator. Simulation

Mohammad Reza Sirouspour; S. E. Salcudean

2001-01-01

483

Hydraulic conductivity tests on compacted clay  

Microsoft Academic Search

Permeability tests were performed in the laboratory on compacted clay to study the effects of type of permeameter, hydraulic anisotropy, diameter of test specimens, storage time, and desiccation cracking. Essentially identical hydraulic conductivities were measured with compaction-mold, consolidationcell, and flexible-wall permeameters. With good bonding between lifts, hydraulic conductivity was isotropic. Test specimens having a diameter of 15 cm were twice

Stephen S. Boynton; David E. Daniel

1985-01-01

484

Variable-Displacement Hydraulic Drive Unit  

NASA Technical Reports Server (NTRS)

Hydraulic power controlled through multiple feedback loops. In hydraulic drive unit, power closely matched to demand, thereby saving energy. Hydraulic flow to and from motor adjusted by motor-control valve connected to wobbler. Wobbler angle determines motor-control-valve position, which in turn determines motor displacement. Concept applicable to machine tools, aircraft controls, and marine controls.

Lang, D. J.; Linton, D. J.; Markunas, A.

1986-01-01

485

Hydraulic servo mechanism of automatic transmission for vehicle  

Microsoft Academic Search

In a vehicle having an automatic transmission, a hydraulic servo control mechanism is described comprising: a hydraulic pressure source, a hydraulic servo; an accumulator; a drain oil line; interconnecting passage means providing a fluid path from the hydraulic pressure source to the hydraulic servo and from the hydraulic servo to the drain oil line; a selector valve, connected in the

K. Sumiya; Y. Sakaguchi; Y. Taga; S. Kubo; S. Moroto

1988-01-01

486

Water Modeling of Self-Braking Submerged Entry Nozzle Used for Steel Continuous Casting Mold  

NASA Astrophysics Data System (ADS)

Slag entrainment in a continuous casting mold is one of the major causes of macro nonmetallic inclusions in continuous casting steel products. Stabilizing the level fluctuation is an important factor to improve steel quality. A new type of submerged entry nozzle (SEN) named self-braking SEN was designed. In the current study, water modeling experiments were performed to study the effect of self-braking SEN on level fluctuation in a continuous casting slab mold. The level position and the root mean square value of level fluctuation were analyzed through the online detection data. The results showed that the flow in the mold was more symmetrical and the tracer dispersion was more uniform. Moreover, the meniscus was also more uniform than the conventional nozzle with the self-braking SEN, especially at high casting speed.

Chen, Yongfeng; Zhang, Lifeng; Yang, Shufeng; Li, Jingshe

2012-09-01

487

Effect of design factors on surface temperature and wear in disk brakes  

NASA Technical Reports Server (NTRS)

The temperatures, friction, wear and contact conditions that occur in high energy disk brakes are studied. Surface and near surface temperatures were monitored at various locations in a caliper disk brake during drag type testing, with friction coefficient and wear rates also being determined. The recorded transient temperature distributions in the friction pads and infrared photographs of the rotor disk surface both showed that contact at the friction surface was not uniform, with contact areas constantly shifting due to nonuniform thermal expansion and wear. The effect of external cooling and of design modifications on friction, wear and temperatures was also investigated. It was found that significant decreases in surface temperature and in wear rate can be achieved without a reduction in friction either by slotting the contacting face of the brake pad or by modifying the design of the pad support to improve pad compliance. Both design changes result in more uniform contact conditions on the friction surface.

Santini, J. J.; Kennedy, F. E.; Ling, F. F.

1976-01-01

488

Predicted values of braking indexes and second frequency derivatives for magnetars  

NASA Astrophysics Data System (ADS)

To date, the observational determination of braking indexes of magnetars is still an open question due to the lack of long-term radio emission and strong timing noise. Based on the assumption that the real ages of magnetars are the ages of their host supernova remnants (SNRs), expanding diffuse gaseous nebulae resulting from explosions of massive stars, we obtain the sizes of the braking index n for 11 magnetar candidates with SNRs. According to our calculations, the magnetar braking indexes will be constrained within the range of about 1-40, assuming the measurements of SNRs are reliable. We also investigate the frequency parameters of magnetars with associated SNRs, and estimate possible wind luminosities for magnetars with n< 3 and magnetic field decay rates for magnetars with n> 3.

Gao, Z. F.; Zhao, X. J.; Song, D. L.; Liu, N.; Wang, N.

2014-09-01

489

Analysis of the minimum swerving distance for the development of a motorcycle autonomous braking system.  

PubMed

In the recent years the autonomous emergency brake (AEB) was introduced in the automotive field to mitigate the injury severity in case of unavoidable collisions. A crucial element for the activation of the AEB is to establish when the obstacle is no longer avoidable by lateral evasive maneuvers (swerving). In the present paper a model to compute the minimum swerving distance needed by a powered two-wheeler (PTW) to avoid the collision against a fixed obstacle, named last-second swerving model (Lsw), is proposed. The effectiveness of the model was investigated by an experimental campaign involving 12 volunteers riding a scooter equipped with a prototype autonomous emergency braking, named motorcycle autonomous emergency braking system (MAEB). The tests showed the performance of the model in evasive trajectory computation for different riding styles and fixed obstacles. PMID:23792616

Giovannini, Federico; Savino, Giovanni; Pierini, Marco; Baldanzini, Niccolò

2013-10-01

490

Sluggish vagal brake reactivity to physical exercise challenge in children with selective mutism.  

PubMed

Cardiovascular response patterns to laboratory-based social and physical exercise challenges were evaluated in 69 children and adolescents, 20 with selective mutism (SM), to identify possible neurophysiological mechanisms that may mediate the behavioral features of SM. Results suggest that SM is associated with a dampened response of the vagal brake to physical exercise that is manifested as reduced reactivity in heart rate and respiration. Polyvagal theory proposes that the regulation of the vagal brake is a neurophysiological component of an integrated social engagement system that includes the neural regulation of the laryngeal and pharyngeal muscles. Within this theoretical framework, sluggish vagal brake reactivity may parallel an inability to recruit efficiently the structures involved in speech. Thus, the findings suggest that dampened autonomic reactivity during mobilization behaviors may be a biomarker of SM that can be assessed independent of the social stimuli that elicit mutism. PMID:22293007

Heilman, Keri J; Connolly, Sucheta D; Padilla, Wendy O; Wrzosek, Marika I; Graczyk, Patricia A; Porges, Stephen W

2012-02-01

491

[Exploration of the broken parts of a brake hose by ATR-FTIR and SEM].  

PubMed

ATR-FTIR and SEM were respectively utilized to analyze the chemical components and to observe the micromorphology of a broken brake hose from a traffic case, which could be a supplementary for the traditional microscopic examination. The instrumental analysis results indicated that the rubber from the brake hose had already aged; the rubber from external side had experienced brittle fracture and there were original hollows in the rubber from internal side. The breaking of the brake hose resulted from all these reasons. The experimental results also demonstrated that the fact could be reflected efficiently, accurately and objectively by the application of ATR-FTIR and SEM to the physical evidence from a case. Therefore, it could be an effective complement for traditional traffic trace examination. PMID:21714231

Wang, Yuan-Feng; Wang, Lian-Ming; Li, Bing

2011-04-01

492

Compliant mechanism road bicycle brake: a rigid-body replacement case study  

SciTech Connect

The design of high-performance bicycle brakes is complicated by the competing design objectives of increased performance and low weight. But this challenge also provides a good case study to demonstrate the design of compliant mechanisms to replace current rigid-link mechanisms. This paper briefly reviews current road brake designs, demonstrates the use of rigid-body replacement synthesis to design a compliant mechanism, and illustrates the combination of compliant mechanism design tools. The resulting concept was generated from the modified dual-pivot brake design and is a partially compliant mechanism where one pin has the dual role of a joint and a mounting pin. The pseudo-rigid-body model, finite element analysis, and optimization algorithms are used to generate design dimensions, and designs are considered for both titanium and E-glass flexures. The resulting design has the potential of reducing the part count and overall weight while maintaining a performance similar to the benchmark.

Olsen, Brian M [Los Alamos National Laboratory; Howell, Larry L [NON LANL; Magleby, Spencer P [NON LANL

2011-01-19

493

Determination of the effectiveness and feasibility of regenerative braking systems on electric and other automobiles. Volume I. Summary. Final report  

Microsoft Academic Search

A report is given of a study conducted by Lawrence Livermore Laboratory in which a determination of the effectiveness and feasibility of regenerative braking systems on electric and other automobiles was made. Regenerative braking concepts applicable to autos utilizing electric, hybrid, or heat engine power systems were evaluated to determine performance improvement, energy savings, and cost effectiveness. Two major conclusions

D. D. Davis; R. A. Renner; F. C. Younger; R. C. Epps; S. S. Lerner

1977-01-01

494

Initial results using Eddy Current Brakes as Fast Turn-on, Programmable Physical Dampers for Haptic Rendering  

E-print Network

Initial results using Eddy Current Brakes as Fast Turn-on, Programmable Physical Dampers for Haptic Machines McGill University, Montr´eal, Qu´ebec, Canada ABSTRACT We demonstrate the use of eddy current propose an alternate method to create damping in a haptic interface that uses eddy current brakes. 2 EDDY

Hayward, Vincent

495

A new method for on-line monitoring of brake fluid condition using an enclosed reference probe  

Microsoft Academic Search

This paper presents a new method for on-line monitoring of the liquid level and water content of brake fluid using an enclosed reference probe as the capacitive sensing part. The probe has an enclosed cavity at the end which is designed to hold fresh brake fluid as an on-line reference. Three capacitances formed by four electrodes are used for the

Chuantong Wang; Katsunori Shida

2007-01-01

496

Journal home page: http://www.sciencedirect.com/science/journal/0022460X Investigation of the relationship between damping and mode-coupling patterns in case of brake squeal  

E-print Network

is currently a key issue in brake development. This brake noise, with frequencies ranging from one to ten kilo of the relationship between damping and mode-coupling patterns in case of brake squeal Journal of Sound and Vibration in case of brake squeal Guillaume FRITZ1,2 , Jean-Jacques SINOU2 , Jean-Marc DUFFAL1 , Louis J ´EZ´EQUEL2

Paris-Sud XI, Université de

497

Gas-to-hydraulic power converter  

NASA Technical Reports Server (NTRS)

A gas piston driven hydraulic piston pump is described in which the gas cycle is of high efficiency by injecting the gas in slugs at the beginning of each power stroke. The hydraulic piston is disposed to operate inside the as piston, and the two pistons, both slidably but nonrotatably mounted, are coupled together with a rotating but non-sliding motion transfer ring extending into antifriction grooves in the sidewalls of the two pistons. To make the hydraulic piston move at a constant speed during constant hydraulic horsepower demand and thus exert a constant pressure on the hydraulic fluid, these grooves are machined with variable pitches and one is the opposite of the other, i.e., the gas piston groove increases in pitch during its power stroke while the hydraulic piston groove decreases. Any number of piston assembly sets may be used to obtain desired hydraulic horsepower.

Galloway, C. W. (inventor)

1982-01-01

498

Gas-to-hydraulic power converter  

NASA Astrophysics Data System (ADS)

A gas piston driven hydraulic piston pump is described in which the gas cycle is of high efficiency by injecting the gas in slugs at the beginning of each power stroke. The hydraulic piston is disposed to operate inside the as piston, and the two pistons, both slidably but nonrotatably mounted, are coupled together with a rotating but non-sliding motion transfer ring extending into antifriction grooves in the sidewalls of the two pistons. To make the hydraulic piston move at a constant speed during constant hydraulic horsepower demand and thus exert a constant pressure on the hydraulic fluid, these grooves are machined with variable pitches and one is the opposite of the other, i.e., the gas piston groove increases in pitch during its power stroke while the hydraulic piston groove decreases. Any number of piston assembly sets may be used to obtain desired hydraulic horsepower.

Galloway, C. W.

1981-02-01

499

Brake performance of core-shell structured carbonyl iron/silica based magnetorheological suspension  

NASA Astrophysics Data System (ADS)

Chemically stable core-shell structured magnetic particles were synthesized by coating soft-magnetic carbonyl iron (CI) microspheres with silica through a sol-gel reaction, and applied as magnetorheological (MR) materials for a specially designed small-sized MR brake. The dynamic yield stress of the MR suspension containing the synthesized particles was also measured using a rotational rheometer under an applied magnetic field. The performance characteristics of the MR brake, including field dependent torque, hysteresis, time and torque tracking control responses were examined. The results showed that with the exception of the settling time, the other response times were faster than those of the pristine CI based MR fluid.

Nguyen, Phuong-Bac; Do, Xuan-Phu; Jeon, Juncheol; Choi, Seung-Bok; Liu, Ying Dan; Choi, Hyoung Jin

2014-10-01

500

Continuous variable transmission and regenerative braking devices in bicycles utilizing magnetorheological fluids  

NASA Astrophysics Data System (ADS)

The use of magnetorheological (MR) fluids in vehicles has been gaining popular recently due to its controllable nature, which gives automotive designers more dimensions of freedom in functional designs. However, not much attention has been paid to apply it to bicycles. This paper is aimed to study the feasibility of applying MR fluids in different dynamic parts of a bicycle such as the transmission and braking systems. MR continuous variable transmission (CVT) and power generator assisted in braking systems were designed and analyzed. Both prototypes were fabricated and tested to evaluate their performances. Experimental results showed that the proposed designs are promising to be used in bicycles.

Cheung, Wai Ming; Liao, Wei-Hsin

2013-04-01