Science.gov

Sample records for crawler tractors

  1. Miniature pipe crawler tractor

    DOEpatents

    McKay, Mark D.; Anderson, Matthew O.; Ferrante, Todd A.; Willis, W. David

    2000-01-01

    A pipe crawler tractor may comprise a half tractor assembly having a first base drive wheel, a second base drive wheel, and a top drive wheel. The drive wheels are mounted in spaced-apart relation so that the top drive wheel is positioned between the first and second base drive wheels. The mounting arrangement is also such that the first and second base drive wheels contact the inside surface of the pipe at respective first and second positions and so that the top drive wheel contacts the inside surface of the pipe at a third position, the third position being substantially diametrically opposed to the first and second positions. A control system connected to the half tractor assembly controls the rotation of the first base wheel, the second base wheel, and the top drive wheel to move the half tractor assembly within the pipe.

  2. Self-Pacing a Gross Motor Skills Course: Crawler Tractor Operator, MOS 62E20.

    ERIC Educational Resources Information Center

    Brennan, Mark F.; Taylor, John E.

    As part of the Army's emphasis on performance-oriented instruction in training centers, a study was conducted to determine the feasibility of using self-paced instruction in a gross motor skills course. The Crawler Tractor Operator Course, a seven-week heavy equipment course conducted at Fort Leonard Wood, Missouri was selected for the study…

  3. Pipe crawlers: Versatile adaptations for real applications

    SciTech Connect

    Hapstack, M.; Talarek, T.R.

    1990-01-01

    A problem at the Savannah River Site requires the unique application of a pipe crawler. A number of stainless steel pipes buried in concrete require ultrasonic inspection of the heat affected zones of the welds for detection of flaws or cracks. The paper describes the utilization of an inch-worm motion pipe crawler which negotiates a 90 degree reducing elbow with significant changes in diameter and vertical sections before entering the area of concern. After a discussion of general considerations and problem description, special requirements to meet the objectives and the design approach regarding the tractor, control system, instrument carriage, and radiation protection are discussed. 2 refs., 11 figs. (MB)

  4. Extendable pipe crawler

    DOEpatents

    Hapstack, Mark

    1991-01-01

    A pipe crawler having a front leg assembly and a back leg assembly connected together by two air cylinders, each leg assembly having four extendable legs and a pair of actuators for sliding the extendable legs radially outward to increase the range of the legs when the pipe crawler enters a section of a pipe having a larger diameter. The crawler crawls by "inchworm"-like motion, the front leg assembly and back leg assembly alternately engaging and disengaging the wall of the pipe to hold the pipe crawler as the air cylinders alternately advance the front leg assembly and bring up the rear leg assembly. The pair of actuators of each leg assembly are parallel, adjacent and opposing acting so that each slides two adjacent extendable legs radially outward.

  5. Extendable pipe crawler

    DOEpatents

    Hapstack, M.

    1991-05-28

    A pipe crawler is described having a front leg assembly and a back leg assembly connected together by two air cylinders, each leg assembly having four extendable legs and a pair of actuators for sliding the extendable legs radially outward to increase the range of the legs when the pipe crawler enters a section of a pipe having a larger diameter. The crawler crawls by inchworm'-like motion, the front leg assembly and back leg assembly alternately engaging and disengaging the wall of the pipe to hold the pipe crawler as the air cylinders alternately advance the front leg assembly and bring up the rear leg assembly. The pair of actuators of each leg assembly are parallel, adjacent and opposing acting so that each slides two adjacent extendable legs radially outward. 5 figures.

  6. Pipe crawler apparatus

    DOEpatents

    Hovis, Gregory L.; Erickson, Scott A.; Blackmon, Bruce L.

    2002-01-01

    A pipe crawler apparatus particularly useful for 3-inch and 4-inch diameter pipes is provided. The pipe crawler apparatus uses a gripping apparatus in which a free end of a piston rod is modified with a bearing retaining groove. Bearings, placed within the groove, are directed against a camming surface of three respective pivoting support members. The non-pivoting ends of the support members carry a foot-like gripping member that, upon pivoting of the support member, engages the interior wall of the pipe.

  7. Crawler Solids Unknown Analysis

    NASA Technical Reports Server (NTRS)

    Frandsen, Athela

    2016-01-01

    Crawler Transporter (CT) #2 has been undergoing refurbishment to carry the Space Launch System (SLS). After returning to normal operation, multiple filters of the gear box lubrication system failed/clogged and went on bypass during a test run to the launch pad. Analysis of the filters was done in large part with polarized light microscopy (PLM) to identify the filter contaminates and the source of origin.

  8. Progress report on Bertelsen research and development of an air cushion crawler all-terrain vehicle

    NASA Astrophysics Data System (ADS)

    Bertelsen, W. R.

    1987-06-01

    The ACV is an exceptional amphibian but it is not, nor is any other existing craft, an all-terrain vehicle (ATV). Using the best elements of the ACV in an air-cushion crawler tractor, a true ATV can be attained. A conventional crawler drive train will propel two tracks as pressurized, propulsive pontoons. The key to a successful ATV is in perfecting efficient, durable, sliding seals to allow the belt to move in its orbit around the track unit and maintain its internal pressure. After deriving the adequate seal, a 12 inch wide x 86 inch long endless rubber belt was fitted bilateral seals and slide plates with internal guide wheels fore and aft with a 21 inch wheel base. From this approximately one-quarter scale model, full-scale air track crawlers, true ATVs, of any size and capacity can be produced.

  9. Tether Elevator Crawler Systems (TECS)

    NASA Technical Reports Server (NTRS)

    Swenson, Frank R.

    1987-01-01

    One of the needs of the experimenters on the space station is access to steady and controlled-variation microgravity environments. A method of providing these environments is to place the experiment on a tether attached to the space station. This provides a high degree of isolation from structural oscillations and vibrations. Crawlers can move these experiments along the tethers to preferred locations, much like an elevator. This report describes the motion control laws developed for these crawlers and the testing of laboratory models of these tether elevator crawlers.

  10. Pipe crawler with extendable legs

    DOEpatents

    Zollinger, William T.

    1992-01-01

    A pipe crawler for moving through a pipe in inchworm fashion having front and rear leg assemblies separated by air cylinders to increase and decrease the spacing between assemblies. Each leg of the four legs of an assembly is moved between a wall-engaging, extended position and a retracted position by a separate air cylinder. The air cylinders of the leg assemblies are preferably arranged in pairs of oppositely directed cylinders with no pair lying in the same axial plane as another pair. Therefore, the cylinders can be as long a leg assembly is wide and the crawler can crawl through sections of pipes where the diameter is twice that of other sections. The crawler carries a valving system, a manifold to distribute air supplied by a single umbilical air hose to the various air cylinders in a sequence controlled electrically by a controller. The crawler also utilizes a rolling mechanism, casters in this case, to reduce friction between the crawler and pipe wall thereby further extending the range of the pipe crawler.

  11. Pipe crawler with extendable legs

    DOEpatents

    Zollinger, W.T.

    1992-06-16

    A pipe crawler for moving through a pipe in inchworm fashion having front and rear leg assemblies separated by air cylinders to increase and decrease the spacing between assemblies. Each leg of the four legs of an assembly is moved between a wall-engaging, extended position and a retracted position by a separate air cylinder. The air cylinders of the leg assemblies are preferably arranged in pairs of oppositely directed cylinders with no pair lying in the same axial plane as another pair. Therefore, the cylinders can be as long as a leg assembly is wide and the crawler can crawl through sections of pipes where the diameter is twice that of other sections. The crawler carries a valving system, a manifold to distribute air supplied by a single umbilical air hose to the various air cylinders in a sequence controlled electrically by a controller. The crawler also utilizes a rolling mechanism, casters in this case, to reduce friction between the crawler and pipe wall thereby further extending the range of the pipe crawler. 8 figs.

  12. [Vibration on agricultural tractors].

    PubMed

    Peretti, Alessandro; Delvecchio, Simone; Bonomini, Francesco; di Bisceglie, Anita Pasqua; Colosio, Claudio

    2013-01-01

    In the article, details related to the diffusion of agricultural tractors in Italy are given and considerations about the effects of vibration on operators, the sources of vibration and suggestions to reduce them are presented. The acceleration values observed in Italy amongst 244 tractors and levels of worker exposure are shown by means of histograms. The relevant data variability is discussed. PMID:24303716

  13. Pipe crawler with stabilizing midsection

    SciTech Connect

    Zollinger, W.T.; Treanor, R.C.

    1993-09-20

    This invention is comprised of a pipe crawler having a midsection that provides the stability and flexibility to allow the pipe crawler to negotiate curved and uneven segments of piping while traveling through piping systems. The pipe crawler comprises a front leg assembly, a rear leg assembly, a midsection with a gimbal at each end for connecting the midsection to the front and rear leg assemblies in a flexible manner, and an air cylinder for changing the distance between the front and rear leg assemblies. The pipe crawler moves in ``inch worm`` fashion with the front and rear leg assemblies alternating between an extended and a retracted position as the air cylinder moves the retracted leg assembly forward. The midsection has a plurality of legs extending radially for holding the midsection within a maximum displacement from the piping axis so that the gimbals are not pivoted to extreme angles where they might lock up or seize. When the midsection is displaced sufficiently, its legs with wheels on each end engage the interior surface of the piping and prevent further displacement. Using two gimbals divides the angle between the planes defined by the front and rear leg assemblies which also helps to prevent excessive gimbal pivoting.

  14. Pipe crawler with stabilizing midsection

    DOEpatents

    Zollinger, William T.; Treanor, Richard C.

    1994-01-01

    A pipe crawler having a midsection that provides the stability and flexibty to allow the pipe crawler to negotiate curved and uneven segments of piping while traveling through piping systems. The pipe crawler comprises a front leg assembly, a rear leg assembly, a midsection with a gimbal at each end for connecting the midsection to the front and rear leg assemblies in a flexible manner, and an air cylinder for changing the distance between the front and rear leg assemblies. The pipe crawler moves in "inch worm" fashion with the front and rear leg assemblies alternating between an extended and a retracted position as the air cylinder moves the retracted leg assembly forward. The midsection has a plurality of legs extending radially for holding the midsection within a maximum displacement from the piping axis so that the gimbals are not pivoted to extreme angles where they might lock up or seize. When the midsection is displaced sufficiently, its legs with wheels on each end engage the interior surface of the piping and prevent further displacement. Using two gimbals divides the angle between the planes defined by the front and rear leg assemblies which also helps to prevent excessive gimbal pivoting.

  15. Pipe crawler with stabilizing midsection

    DOEpatents

    Zollinger, W.T.; Treanor, R.C.

    1994-12-27

    A pipe crawler is described having a midsection that provides the stability and flexibility to allow the pipe crawler to negotiate curved and uneven segments of piping while traveling through piping systems. The pipe crawler comprises a front leg assembly, a rear leg assembly, a midsection with a gimbal at each end for connecting the midsection to the front and rear leg assemblies in a flexible manner, and an air cylinder for changing the distance between the front and rear leg assemblies. The pipe crawler moves in ''inch worm'' fashion with the front and rear leg assemblies alternating between an extended and a retracted position as the air cylinder moves the retracted leg assembly forward. The midsection has a plurality of legs extending radially for holding the midsection within a maximum displacement from the piping axis so that the gimbals are not pivoted to extreme angles where they might lock up or seize. When the midsection is displaced sufficiently, its legs with wheels on each end engage the interior surface of the piping and prevent further displacement. Using two gimbals divides the angle between the planes defined by the front and rear leg assemblies which also helps to prevent excessive gimbal pivoting. 5 figures.

  16. H-Canyon Recovery Crawler

    SciTech Connect

    Kriikku, E. M.; Hera, K. R.; Marzolf, A. D.; Phillips, M. H.

    2015-08-01

    The Nuclear Material Disposition Project group asked the Savannah River National Lab (SRNL) Research and Development Engineering (R&DE) department to help procure, test, and deploy a remote crawler to recover the 2014 Inspection Crawler (IC) that tipped over in the H-Canyon Air Exhaust Tunnel. R&DE wrote a Procurement Specification for a Recovery Crawler (RC) and SRNS Procurement Department awarded the contract to Power Equipment Manufacturing Inc. (PEM). The PEM RC was based on their standard sewer inspection crawler with custom arms and forks added to the front. The arms and forks would be used to upright the 2014 Inspection Crawler. PEM delivered the RC and associated cable reel, 2014 Inspection Crawler mockup, and manuals in late April 2015. R&DE and the team tested the crawler in May of 2015 and made modifications based on test results and Savannah River Site (SRS) requirements. R&DE delivered the RC to H-Area at the end of May. The team deployed the RC on June 9, 10, and 11, 2015 in the H-Canyon Air Exhaust Tunnel. The RC struggled with some obstacles in the tunnel, but eventually made it to the IC. The team spent approximately five hours working to upright the IC and eventually got it on its wheels. The IC travelled approximately 20 feet and struggled to drive over debris on the air tunnel floor. Unfortunately the IC tripped over trying to pass this obstacle. The team decided to leave the IC in this location and inspect the tunnel with the RC. The RC passed the IC and inspected the tunnel as it travelled toward H-Canyon. The team turned the RC around when it was about 20 feet from the H-Canyon crossover tunnel. From that point, the team drove the RC past the manway towards the new sand filter and stopped approximately 20 feet from the new sand filter. The team removed the RC from the tunnel, decontaminated the RC, and stored it the manway building, 294-2H. The RC deployment confirmed the IC was not in a condition to perform useful tunnel inspections and

  17. Tractor beams for optical micromanipulation

    NASA Astrophysics Data System (ADS)

    Yevick, Aaron; Grier, David G.

    2016-03-01

    Tractor beams are traveling waves that transport illuminated objects in the retrograde direction relative to the direction of propagation. The theory of photokinetic effects identifies design criteria for long-range general- purpose tractor beams. These criteria distinguish first-order tractor beams that couple to induced dipole moments from higher-order tractor beams that rely on coupling to higher-order multipole moments to achieve pulling. First-order tractor beams are inherently longer-ranged and operate on a wider variety of materials. We explore the physics of first-order tractor beams in the context of a family of generalized solenoidal waves.

  18. Tractor Operation and Daily Care.

    ERIC Educational Resources Information Center

    Fore, J. M.; And Others

    Written for the tractor operator, the manual describes, with the aid of colored illustrations and diagrams, the tasks involved in the proper operation and daily maintenance of tractors. It offers explanations for the desirability of the various servicing and adjustment operations, as well as guidelines for tractor operation and safety. The…

  19. Tractor & Machinery Safety. 1984 Revision.

    ERIC Educational Resources Information Center

    Montana State Office of Public Instruction, Helena. Dept. of Vocational Education Services.

    This curriculum guide is intended for use in teaching an instructional unit in tractor and machinery safety that is geared toward college freshmen. Addressed in the individual lessons of the unit are the following topics: understanding the importance of safe and efficient tractor operation, understanding the characteristics of tractors, preparing…

  20. Two hybrid versions of a forest tractor

    SciTech Connect

    Baldini, S.S.; Carlini, M.; Abenavoli, R.I.; Kormanski, H.; Rudzinska, K.

    1998-07-01

    In this paper the authors consider two different hybrid drive systems for a small caterpillar tractor used for logging in forests. The first one is a series hybrid electric propulsion system. It is composed of an internal combustion (IC) engine, an electric generator, a group of lead-acid batteries and electric drive motors. The second one is a series hybrid hydraulic propulsion system. It is composed of an IC engine, hydraulic pump, a group of hydraulic accumulators and hydraulic motors. Generally, vehicles employed in forestry and agricultural works are characterized by low utilization of the available installed power. It stems from oversizing IC engine in a conventional driveline in order to supply the maximum power. Since the mean required power over a duty cycle is often substantially lower, a series hybrid drive system has potential for improving fuel economy, reducing pollutant emission and noise level. Series hybrids generally feature small engines because they are sized to provide only the average vehicle power demand. Sizing of the engine and other drive system components is significantly different in a hybrid vehicle than in a conventional forest tractor in which the engine is the only source of power to drive the vehicle or to lift wood. In a hybrid crawler, the power required at any time is split between auxiliary power unit (IC engine/electric generator or IC engine/hydraulic pump) and load leveling device (batteries or hydraulic accumulators). The engine can be decoupled from the terrain load. This may allow the engine to be operated near its most efficient fuel consumption conditions or else turned off. The presented hybrid powertrains are compared with the conventional one and one to another. Each of them has its own advantages and disadvantages. To evaluate the performance of the proposed solutions a special forest cycle was used.

  1. Acoustic tractor beam.

    PubMed

    Démoré, Christine E M; Dahl, Patrick M; Yang, Zhengyi; Glynne-Jones, Peter; Melzer, Andreas; Cochran, Sandy; MacDonald, Michael P; Spalding, Gabriel C

    2014-05-01

    Negative radiation forces act opposite to the direction of propagation, or net momentum, of a beam but have previously been challenging to definitively demonstrate. We report an experimental acoustic tractor beam generated by an ultrasonic array operating on macroscopic targets (>1 cm) to demonstrate the negative radiation forces and to map out regimes over which they dominate, which we compare to simulations. The result and the geometrically simple configuration show that the effect is due to nonconservative forces, produced by redirection of a momentum flux from the angled sides of a target and not by conservative forces from a potential energy gradient. Use of a simple acoustic setup provides an easily understood illustration of the negative radiation pressure concept for tractor beams and demonstrates continuous attraction towards the source, against a net momentum flux in the system. PMID:24836252

  2. Acoustic Tractor Beam

    NASA Astrophysics Data System (ADS)

    Démoré, Christine E. M.; Dahl, Patrick M.; Yang, Zhengyi; Glynne-Jones, Peter; Melzer, Andreas; Cochran, Sandy; MacDonald, Michael P.; Spalding, Gabriel C.

    2014-05-01

    Negative radiation forces act opposite to the direction of propagation, or net momentum, of a beam but have previously been challenging to definitively demonstrate. We report an experimental acoustic tractor beam generated by an ultrasonic array operating on macroscopic targets (>1 cm) to demonstrate the negative radiation forces and to map out regimes over which they dominate, which we compare to simulations. The result and the geometrically simple configuration show that the effect is due to nonconservative forces, produced by redirection of a momentum flux from the angled sides of a target and not by conservative forces from a potential energy gradient. Use of a simple acoustic setup provides an easily understood illustration of the negative radiation pressure concept for tractor beams and demonstrates continuous attraction towards the source, against a net momentum flux in the system.

  3. Vegetable oils for tractors

    SciTech Connect

    Moroney, M.

    1981-11-14

    Preliminary tests by the Agricultural Institute, show that tractors can be run on a 50:50 rape oil-diesel mixture or on pure rape oil. In fact, engine power actually increased slightly with the 50:50 blend but decreased fractionally with pure rape oil. Research at the North Dakota State University on using sunflower oil as an alternative to diesel fuel is also noted.

  4. Crawler-Transporter Time-Lapse

    NASA Video Gallery

    Time-lapse video shows crawler-transporter No. 2 traveling from the Vehicle Assembly Building to Launch Pad 39A at NASA's Kennedy Space Center in Florida. The move was performed by the Ground Syste...

  5. Tractor Safety. Unit A-9.

    ERIC Educational Resources Information Center

    Luft, Vernon D.; Backlund, Paul

    This document is a teacher's guide for a unit in tractor and machinery safety for college freshmen. It is intended to be used for 10 hours of instruction for freshmen who are intending to work on or around machinery. Safety hazards directly and indirectly related to many types of machinery are covered in addition to tractors. The objectives of the…

  6. Dynamic acoustic tractor beams

    NASA Astrophysics Data System (ADS)

    Mitri, F. G.

    2015-03-01

    Pulling a sphere and vibrating it around an equilibrium position by amplitude-modulation in the near-field of a single finite circular piston transducer is theoretically demonstrated. Conditions are found where a fluid hexane sphere (with arbitrary radius) chosen as an example, centered on the axis of progressive propagating waves and submerged in non-viscous water, experiences an attractive (steady) force pulling it towards the transducer, as well as an oscillatory force forcing it to vibrate back-and-forth. Numerical predictions for the dynamic force illustrate the theory and suggest an innovative method in designing dynamic acoustical tractor beams.

  7. Dynamic acoustic tractor beams

    SciTech Connect

    Mitri, F. G.

    2015-03-07

    Pulling a sphere and vibrating it around an equilibrium position by amplitude-modulation in the near-field of a single finite circular piston transducer is theoretically demonstrated. Conditions are found where a fluid hexane sphere (with arbitrary radius) chosen as an example, centered on the axis of progressive propagating waves and submerged in non-viscous water, experiences an attractive (steady) force pulling it towards the transducer, as well as an oscillatory force forcing it to vibrate back-and-forth. Numerical predictions for the dynamic force illustrate the theory and suggest an innovative method in designing dynamic acoustical tractor beams.

  8. Photocopy of drawing. LAUNCH COMPLEX 39, CRAWLER TRANSPORTER. NASA, John ...

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

    Photocopy of drawing. LAUNCH COMPLEX 39, CRAWLER TRANSPORTER. NASA, John F. Kennedy Space Center, Florida. Drawing 75M05761, Marion Power Shovel Company, October 1963. CRAWLER TRUCK ASSEMBLY-FIELD WELDMENT SECTIONS & DETAILS. Sheet 4 - Cape Canaveral Air Force Station, Launch Complex 39, Crawler Transporters, Launcher Road, East of Kennedy Parkway North, Cape Canaveral, Brevard County, FL

  9. Photocopy of drawing. LAUNCH COMPLEX 39, CRAWLER TRANSPORTER. NASA, John ...

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

    Photocopy of drawing. LAUNCH COMPLEX 39, CRAWLER TRANSPORTER. NASA, John F. Kennedy Space Center, Florida. Drawing 75M05761, Marion Power Shovel Company, October 1963. CRAWLER TRUCK ASSEMBLY-SIDE VIEW. Sheet 3 - Cape Canaveral Air Force Station, Launch Complex 39, Crawler Transporters, Launcher Road, East of Kennedy Parkway North, Cape Canaveral, Brevard County, FL

  10. Photocopy of drawing. LAUNCH COMPLEX 39, CRAWLER TRANSPORTER. NASA, John ...

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

    Photocopy of drawing. LAUNCH COMPLEX 39, CRAWLER TRANSPORTER. NASA, John F. Kennedy Space Center, Florida. Drawing 75M05761, Marion Power Shovel Company, October 1963. CRAWLER TRUCK ASSEMBLY-PLAN VIEW. Sheet 2 - Cape Canaveral Air Force Station, Launch Complex 39, Crawler Transporters, Launcher Road, East of Kennedy Parkway North, Cape Canaveral, Brevard County, FL

  11. Aerial view of the KSC crawler transporters

    NASA Technical Reports Server (NTRS)

    1998-01-01

    In this aerial view the Crawler Transporter Maintenance Building (center) sits between two crawler transporters. The KSC crawlers are the largest tracked vehicles known. Once used to move assembled Apollo/Saturn from the VAB to the launch pad, they are now used for transporting Shuttle vehicles. They move the Mobile Launcher Platform into the Vehicle Assembly Building and then to the Launch Pad with an assembled space vehicle. Maximum speed is 1.6 km (one mile) per hour loaded, about 3.2 km (2 miles) per hour unloaded. Launch Pad to VAB trip time with the Mobile Launch Platform is about 5 hours. The crawler burns 568 liters (150 gallons) of diesel oil per mile. KSC's two crawlers have accumulated 1,243 miles since 1977. Including the Apollo years, the transporters have racked up 2,526 miles, about the same distance as a one-way trip from KSC to Los Angeles by interstate highway or a round trip between KSC and New York City.

  12. Results from a Web Impact Factor Crawler.

    ERIC Educational Resources Information Center

    Thelwall, Mike

    2001-01-01

    Discusses Web impact factors (WIFs), Web versions of the impact factors for journals, and how they can be calculated by using search engines. Highlights include HTML and document indexing; Web page links; a Web crawler designed for calculating WIFs; and WIFs for United Kingdom universities that measured research profiles or capability. (Author/LRW)

  13. ROPS deficiency of gray-market tractors.

    PubMed

    Myers, M L; Purschwitz, M A

    2012-04-01

    Many used tractors that are imported from Japan are adding to the current national inventory in the U.S. and Canada of farm tractors that lack a rollover protective structure (ROPS). Gray-market tractors are built for use by the manufacturer for a certain country but are imported against the manufacture's wishes to a second country for use there, usually as a used tractor. Gray-market tractors may lack ROPS and seatbelts, depending on the date of manufacturer. The objective of this investigation is to describe the gray market for tractors imported from Japan into the U.S. and the policy implications regarding the hazards associated with these imports. Operator manuals and warning labels are typically not written in English. Foreign manufacturers that market tractors in the U.S. have established a variety of disincentives for the importation of gray-market tractors, including issuing warnings, not servicing or providing parts for these tractors, and banning their importation through actions by the U.S. International Trade Commission. Nonetheless, a U.S. market has developed that imports and provides services and parts for gray-market tractors, and some companies provide certified ROPS on the tractors that they sell. A product safety perspective and related policies are presented as an approach to ensuring that these imports are equipped with ROPS and seatbelts. PMID:22655522

  14. Tractor Transmissions. A Teaching Reference.

    ERIC Educational Resources Information Center

    American Association for Agricultural Engineering and Vocational Agriculture, Athens, GA.

    The manual was developed as a reference for teaching students about transmissions in farm tractors. The manual is divided into five sections: (1) transmission history, (2) gears and bearings in transmission, (3) sliding-gear transmissions, (4) planetary gearing, and (5) glossary. The working principles of the sliding-gear transmission, the most…

  15. Space Shuttle Crawler Transporter Sound Attenuation Study

    NASA Technical Reports Server (NTRS)

    Margasahayam, Ravi N.; MacDonald, Rod; Faszer, Clifford

    2004-01-01

    The crawler transporter (CT) is the world's largest tracked vehicle known, weighing 6 million pounds with a length of 131 feet and a width of 113 feet. The Kennedy Space Center (KSC) has two CTs that were designed and built for the Apollo program in the 1960's, maintained and retrofitted for use in the Space Shuttle program. As a key element of the Space Shuttle ground systems, the crawler transports the entire 12-million-pound stack comprising the orbiter, the mobile launch platform (MLP), the external tank (ET), and the solid rocket boosters (SRB) from the Vehicle Assembly Building (VAB) to the launch pad. This rollout, constituting a 3.5-5.0-mile journey at a top speed of 0.9 miles-per-hour, requires over 8 hours to reach either Launch Complex 39A or B. This activity is only a prelude to the spectacle of sound and fury of the Space Shuttle launch to orbit in less than 10 minutes and traveling at orbital velocities of Mach 24. This paper summarizes preliminary results from the Crawler Transporter Sound Attenuation Study, encompassing test and engineering analysis of significant sound sources to measure and record full frequency spectrum and intensity of the various noise sources and to analyze the conditions of vibration. Additionally, data such as ventilation criteria, plus operational procedures were considered to provide a comprehensive noise suppression design for implementation. To date, sound attenuation study and results on Crawler 2 have shown significant noise reductions ranging from 5 to 24 dBA.

  16. Photocopy of drawing. LAUNCH COMPLEX 39, CRAWLER TRANSPORTER. NASA, John ...

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

    Photocopy of drawing. LAUNCH COMPLEX 39, CRAWLER TRANSPORTER. NASA, John F. Kennedy Space Center, Florida. Drawing 79K00081, John F. Kennedy Space Center, December 1969. SYS FUNCTIONAL DRAWING. Sheet 3 - Cape Canaveral Air Force Station, Launch Complex 39, Crawler Transporters, Launcher Road, East of Kennedy Parkway North, Cape Canaveral, Brevard County, FL

  17. Photocopy of drawing. LAUNCH COMPLEX 39, CRAWLER TRANSPORTER. NASA, John ...

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

    Photocopy of drawing. LAUNCH COMPLEX 39, CRAWLER TRANSPORTER. NASA, John F. Kennedy Space Center, Florida. Drawing 79K00088, John F. Kennedy Space Center, November 1969. SYS FUNCTIONAL DRAWING. Sheet 6 - Cape Canaveral Air Force Station, Launch Complex 39, Crawler Transporters, Launcher Road, East of Kennedy Parkway North, Cape Canaveral, Brevard County, FL

  18. Photocopy of drawing. LAUNCH COMPLEX 39, CRAWLER TRANSPORTER. NASA, John ...

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

    Photocopy of drawing. LAUNCH COMPLEX 39, CRAWLER TRANSPORTER. NASA, John F. Kennedy Space Center, Florida. Drawing 79K00088, John F. Kennedy Space Center, November 1969. SYS FUNCTIONAL DRAWING. Sheet 5 - Cape Canaveral Air Force Station, Launch Complex 39, Crawler Transporters, Launcher Road, East of Kennedy Parkway North, Cape Canaveral, Brevard County, FL

  19. Photocopy of drawing. LAUNCH COMPLEX 39, CRAWLER TRANSPORTER. NASA, John ...

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

    Photocopy of drawing. LAUNCH COMPLEX 39, CRAWLER TRANSPORTER. NASA, John F. Kennedy Space Center, Florida. Drawing 75M05760, KSC-Launch Support Equipment Engineering Division, January 1967. GENERAL ARRANGEMENT. Sheet 1 of 4 - Cape Canaveral Air Force Station, Launch Complex 39, Crawler Transporters, Launcher Road, East of Kennedy Parkway North, Cape Canaveral, Brevard County, FL

  20. Photocopy of drawing. LAUNCH COMPLEX 39, CRAWLER TRANSPORTER. NASA, John ...

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

    Photocopy of drawing. LAUNCH COMPLEX 39, CRAWLER TRANSPORTER. NASA, John F. Kennedy Space Center, Florida. Drawing 75M05770, Marion Power Shovel Company, February 1964. OPERATOR'S CAB ASSY. Sheet 1 of 1 - Cape Canaveral Air Force Station, Launch Complex 39, Crawler Transporters, Launcher Road, East of Kennedy Parkway North, Cape Canaveral, Brevard County, FL

  1. Photocopy of drawing. LAUNCH COMPLEX 39, CRAWLER TRANSPORTER. NASA, John ...

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

    Photocopy of drawing. LAUNCH COMPLEX 39, CRAWLER TRANSPORTER. NASA, John F. Kennedy Space Center, Florida. Drawing 75M05760, Marion Power Shovel Company, January 1965. GENERAL ARRANGEMENT. Sheet 3 - Cape Canaveral Air Force Station, Launch Complex 39, Crawler Transporters, Launcher Road, East of Kennedy Parkway North, Cape Canaveral, Brevard County, FL

  2. Photocopy of drawing. LAUNCH COMPLEX 39, CRAWLER TRANSPORTER. NASA, John ...

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

    Photocopy of drawing. LAUNCH COMPLEX 39, CRAWLER TRANSPORTER. NASA, John F. Kennedy Space Center, Florida. Drawing 75M05762, Marion Power Shovel Company, December 1964. CHASSIS STRUCTURE ASSEMBLY. Sheet 2 - Cape Canaveral Air Force Station, Launch Complex 39, Crawler Transporters, Launcher Road, East of Kennedy Parkway North, Cape Canaveral, Brevard County, FL

  3. Microhole Drilling Tractor Technology Development

    SciTech Connect

    Western Well Tool

    2007-07-09

    In an effort to increase the U.S. energy reserves and lower costs for finding and retrieving oil, the USDOE created a solicitation to encourage industry to focus on means to operate in small diameter well-Microhole. Partially in response to this solicitation and because Western Well Tool's (WWT) corporate objective to develop small diameter coiled tubing drilling tractor, WWT responded to and was awarded a contract to design, prototype, shop test, and field demonstrate a Microhole Drilling Tractor (MDT). The benefit to the oil industry and the US consumer from the project is that with the MDT's ability to facilitate Coiled Tubing drilled wells to be 1000-3000 feet longer horizontally, US brown fields can be more efficiently exploited resulting in fewer wells, less environmental impact, greater and faster oil recovery, and lower drilling costs. Shortly after award of the contract, WWT was approached by a major oil company that strongly indicated that the specified size of a tractor of 3.0 inches diameter was inappropriate and that immediate applications for a 3.38-inch diameter tractor would substantially increase the usefulness of the tool to the oil industry. Based on this along with an understanding with the oil company to use the tractor in multiple field applications, WWT applied for and was granted a no-cost change-of-scope contract amendment to design, manufacture, assemble, shop test and field demonstrate a prototype a 3.38 inch diameter MDT. Utilizing existing WWT tractor technology and conforming to an industry developed specification for the tool, the Microhole Drilling Tractor was designed. Specific features of the MDT that increase it usefulness are: (1) Operation on differential pressure of the drilling fluid, (2) On-Off Capability, (3) Patented unique gripping elements (4) High strength and flexibility, (5) Compatibility to existing Coiled Tubing drilling equipment and operations. The ability to power the MDT with drilling fluid results in a highly

  4. Conformal superalgebras via tractor calculus

    NASA Astrophysics Data System (ADS)

    Lischewski, Andree

    2015-01-01

    We use the manifestly conformally invariant description of a Lorentzian conformal structure in terms of a parabolic Cartan geometry in order to introduce a superalgebra structure on the space of twistor spinors and normal conformal vector fields formulated in purely algebraic terms on parallel sections in tractor bundles. Via a fixed metric in the conformal class, one reproduces a conformal superalgebra structure that has been considered in the literature before. The tractor approach, however, makes clear that the failure of this object to be a Lie superalgebra in certain cases is due to purely algebraic identities on the spinor module and to special properties of the conformal holonomy representation. Moreover, it naturally generalizes to higher signatures. This yields new formulas for constructing new twistor spinors and higher order normal conformal Killing forms out of existing ones, generalizing the well-known spinorial Lie derivative. Moreover, we derive restrictions on the possible dimension of the space of twistor spinors in any metric signature.

  5. Plane waves as tractor beams

    NASA Astrophysics Data System (ADS)

    Forgács, Péter; Lukács, Árpád; Romańczukiewicz, Tomasz

    2013-12-01

    It is shown that in a large class of systems, plane waves act as tractor beams: i.e., an incident plane wave can exert a pulling force on the scatterer. The underlying physical mechanism for the pulling force is due to the sufficiently strong scattering of the incoming wave into another mode carrying more momentum, in which case excess momentum is created behind the scatterer. This tractor beam or negative radiation pressure (NRP) effect, is found to be generic in systems with multiple scattering channels. In a birefringent medium, electromagnetic plane waves incident on a thin plate exert NRP of the same order of magnitude as optical radiation pressure, while in artificial dielectrics (metamaterials), the magnitude of NRP can even be macroscopic. In two dimensions, we study various scattering situations on vortices, and NRP is shown to occur by the scattering of heavy baryons into light leptons off cosmic strings, and by neutron scattering off vortices in the XY model.

  6. Tractors, mass, and Weyl invariance

    NASA Astrophysics Data System (ADS)

    Gover, A. R.; Shaukat, A.; Waldron, A.

    2009-05-01

    Deser and Nepomechie established a relationship between masslessness and rigid conformal invariance by coupling to a background metric and demanding local Weyl invariance, a method which applies neither to massive theories nor theories which rely upon gauge invariances for masslessness. We extend this method to describe massive and gauge invariant theories using Weyl invariance. The key idea is to introduce a new scalar field which is constant when evaluated at the scale corresponding to the metric of physical interest. This technique relies on being able to efficiently construct Weyl invariant theories. This is achieved using tractor calculus—a mathematical machinery designed for the study of conformal geometry. From a physics standpoint, this amounts to arranging fields in multiplets with respect to the conformal group but with novel Weyl transformation laws. Our approach gives a mechanism for generating masses from Weyl weights. Breitenlohner-Freedman stability bounds for Anti-de Sitter theories arise naturally as do direct derivations of the novel Weyl invariant theories given by Deser and Nepomechie. In constant curvature spaces, partially massless theories—which rely on the interplay between mass and gauge invariance—are also generated by our method. Another simple consequence is conformal invariance of the maximal depth partially massless theories. Detailed examples for spins s⩽2 are given including tractor and component actions, on-shell and off-shell approaches and gauge invariances. For all spins s⩾2 we give tractor equations of motion unifying massive, massless, and partially massless theories.

  7. DETAIL VIEW OF CONNECTOR FOR MATING TO THE CRAWLER TRANSPORTER ...

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

    DETAIL VIEW OF CONNECTOR FOR MATING TO THE CRAWLER TRANSPORTER - Cape Canaveral Air Force Station, Launch Complex 39, Mobile Launcher Platforms, Launcher Road, East of Kennedy Parkway North, Cape Canaveral, Brevard County, FL

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

    NASA Astrophysics Data System (ADS)

    Nastasoiu, Mircea; Ispas, Nicolae

    2014-06-01

    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.

  9. Assessment of controls layout of Indian tractors.

    PubMed

    Kumar, Adarsh; Bhaskar, Gaikwad; Singh, J K

    2009-01-01

    Tractors in low-income countries are used both for farm and non-farm activities. Most of the tractors being manufactured in India are products of collaboration with other countries. The design of tractors manufactured in India has not changed much in the past five decades especially from an ergonomics point of view, because of economic considerations. This paper describes a tractor control layout assessment with respect to the Indian population and compares the location of controls with workspace envelopes and the IS12343 standard for commonly used tractors on Indian farms. Controls like steering, foot clutch, foot brake, foot accelerator are located in areas defined by IS12343 standard in some tractors but these are not placed in the workspace envelopes of the Indian population. This results in a mismatch between the workspace envelope and location of controls as defined by the standard. The controls need a complete change in their layout to be in the workspace envelopes, as this cannot be achieved by providing seat movement in the horizontal and vertical directions in the present tractor design. PMID:18339354

  10. A spatial information crawler for OpenGIS WFS

    NASA Astrophysics Data System (ADS)

    Jiang, Jun; Yang, Chong-jun; Ren, Ying-chao

    2008-10-01

    The growth of the internet makes it non-trivial to search for the accuracy information efficiently. Topical crawler, which is aiming at a certain area, attracts more and more intention now because it can help people to find out what they need. Furthermore, with the OpenGIS WFS (Web Feature Service) Specification developed by OGC (Open GIS Consortium), much more geospatial data providers adopt this protocol to publish their data on the internet. In this case, a crawler which is aiming at the WFS servers can help people to find the geospatial data from WFS servers. In this paper, we propose a prototype system of a WFS crawler based on the OpenGIS WFS Specification. The crawler architecture, working principles, and detailed function of each component are introduced. This crawler is capable of discovering WFS servers dynamically, saving and updating the service contents of the servers. The data collect by the crawler can be supported to a geospatial data search engine as its data source.

  11. Tractor beams in the Rayleigh limit

    NASA Astrophysics Data System (ADS)

    Yevick, Aaron; Ruffner, David B.; Grier, David G.

    2016-04-01

    A tractor beam is a traveling wave that transports illuminated objects back to its source, opposite to the wave's direction of propagation, along its entire length. The requisite retrograde force arises when an object scatters the wave's momentum density downstream into the direction of propagation and then recoils upstream by conservation of momentum. Achieving this condition imposes constraints on the structure of the wave, which we elucidate in the Rayleigh limit, when the wavelength exceeds the size of the object. Continuously propagation-invariant modes such as Bessel beams do not satisfy these conditions at dipole order in the multipole expansion and so cannot serve as general-purpose long-ranged tractor beams. Modes with discrete propagation invariance, however, can act as first-order tractor beams. We demonstrate this by introducing a class of minimal solenoidal waves together with a set of design criteria that distinguish tractor beams that pull objects from repulsor beams that push them.

  12. Generating stable tractor beams with dielectric metasurfaces

    NASA Astrophysics Data System (ADS)

    Pfeiffer, Carl; Grbic, Anthony

    2015-03-01

    Propagation-invariant beams that pull objects towards a light source are commonly known as tractor beams. Here, an efficient, linearly polarized tractor beam with improved stability is introduced. The beam consists of a superposition of transverse-electric and transverse-magnetic polarized Bessel beams of orders m =+1 and m =-1 . It is shown that this beam can stably pull a wide range of dielectric microparticles arbitrarily long distances, independent of ambient conditions. Next, a straightforward method of generating these high-performance beams is proposed. A Si metasurface transforms an incident linearly polarized Gaussian beam into the desired tractor beam. Full-wave simulations demonstrate that it is possible for this simple geometry to pull a polystyrene sphere a distance equal to the nondiffracting range of the Bessel beam. The simplicity of the setup and the robust performance of the proposed tractor beam significantly enhance the ability to manipulate matter with light.

  13. Keys to Successful Tractor Maintenance Units.

    ERIC Educational Resources Information Center

    Doerr, William A.

    1979-01-01

    To prevent problems with teaching plans, supplement class instruction, and stimulate use of the operator's manual, the teacher can use a series of leaflets. The first leaflet describes the activities and what is expected of the tractor operator's manual. (LRA)

  14. Making 'Tractor Beams' a Reality (Eventually)

    NASA Video Gallery

    Tractor beams -- the ability to trap and move objects using laser light -- are the stuff of science fiction, but a team of NASA scientists has won funding to study the concept for remotely capturin...

  15. Analysis of tractor-related deaths.

    PubMed

    Erkol, Zerrin; Buken, Bora; Hekimoglu, Yavuz; Erkol, Hayri; Ince, Haluk; Erzengin, Omer Utku

    2013-01-01

    The aim of the study was to evaluate the properties of tractor-related death cases and discuss the precautions in order to prevent such events. For this aim, reports made between 2006 and 2009 by the First Specialty Board of Council of Forensic Medicine (FSBCFM), Turkey, were evaluated retrospectively. Forty-one tractor-related death cases were included in this study. Thirty-five (85.4%) of the cases were male. The mean age was 42.52 ± 25.1 (with a range between 1 and 84 years old). The average time interval between the incident and death was 13.76 ± 33.53 days (range: 0-176 days) and 20 (48.8%) cases died on the incident spot or during transportation to the hospital. Among the cases, 34.1% (n = 14) were drivers, whereas 39.0% (n = 16) were passengers and the remaining were pedestrians (26.9%, n = 11). The accident was caused by the tractor rolling over in 34.1%, the victim being run over in 22.0%, and the victim falling from the tractor or trailer in 22.0% of the cases. Most of the events (56.1%) occurred on the road. In conclusion, tractors must not be used as a transportation vehicle for passengers. Periodic training of drivers can be useful for reducing tractor-related accidents. PMID:23540299

  16. INNOVATIVE ELECTROMAGNETIC SENSORS FOR PIPELINE CRAWLERS

    SciTech Connect

    J. Bruce Nestleroth

    2004-05-01

    Internal inspection of pipelines is an important tool for ensuring safe and reliable delivery of fossil energy products. However, not all pipelines can be inspected with current systems that move inside the pipeline propelled by the product flow. Inspection platforms that crawl slowly inside a pipeline are being developed to maneuver past the physical barriers that limit inspection. Battelle is building innovative electromagnetic sensors for pipeline crawlers. The various sensor types will assess a wide range of pipeline anomalies including corrosion, mechanical damage, cracking and seam weld defects. An implementation of two electromagnetic sensors were designed and tested. A pulsed eddy current system that uses sensors to measure the decay of induced eddy currents to establish the wall thickness has excellent potential. The results of experiments are comparable with magnetic flux leakage detecting 10% metal loss steps following a monotonic increase in signal strength. A rotating permanent remote field eddy current exciter was designed and built to produce strong signal levels at the receiver and reduce power consumption. Midway through the development of each technology, both sensor systems have produced results that warrant further development.

  17. Liquid crystal elastomer strips as soft crawlers

    NASA Astrophysics Data System (ADS)

    DeSimone, Antonio; Gidoni, Paolo; Noselli, Giovanni

    2015-11-01

    In this paper, we speculate on a possible application of Liquid Crystal Elastomers to the field of soft robotics. In particular, we study a concept for limbless locomotion that is amenable to miniaturisation. For this purpose, we formulate and solve the evolution equations for a strip of nematic elastomer, subject to directional frictional interactions with a flat solid substrate, and cyclically actuated by a spatially uniform, time-periodic stimulus (e.g., temperature change). The presence of frictional forces that are sensitive to the direction of sliding transforms reciprocal, 'breathing-like' deformations into directed forward motion. We derive formulas quantifying this motion in the case of distributed friction, by solving a differential inclusion for the displacement field. The simpler case of concentrated frictional interactions at the two ends of the strip is also solved, in order to provide a benchmark to compare the continuously distributed case with a finite-dimensional benchmark. We also provide explicit formulas for the axial force along the crawler body.

  18. Miniature Tractor Pull Helps Teach Mechanical Power Transmission.

    ERIC Educational Resources Information Center

    Waggoner, Todd C.

    1996-01-01

    A miniature tractor pull was developed as a high school activity, enabling students to assess a tractor's pulling capabilities and determine subsequent horsepower. The activity takes the textbook concept of horsepower and makes it come alive. (JOW)

  19. View of south elevation of Automotive and Tractor Repair Shops ...

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

    View of south elevation of Automotive and Tractor Repair Shops with the Warehouse Fabrication Shop and Stack in the background, looking from the southwest - Kekaha Sugar Company, Automotive and Tractor Repair Shops, 8315 Kekaha Road, Kekaha, Kauai County, HI

  20. Lube rack of Automotive and Tractor Repair Shops with Warehousefield ...

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

    Lube rack of Automotive and Tractor Repair Shops with Warehouse-field Equipment Repair Shop Building's wall to the right, looking from the south - Kekaha Sugar Company, Automotive and Tractor Repair Shops, 8315 Kekaha Road, Kekaha, Kauai County, HI

  1. INNOVATIVE ELECTROMAGNETIC SENSORS FOR PIPELINE CRAWLERS

    SciTech Connect

    J. Bruce Nestleroth

    2005-11-30

    Internal inspection of pipelines is an important tool for ensuring safe and reliable delivery of fossil energy products. Current inspection systems that are propelled through the pipeline by the product flow cannot be used to inspect all pipelines because of the various physical barriers they encounter. Recent development efforts include a new generation of powered inspection platforms that crawl slowly inside a pipeline and are able to maneuver past the physical barriers that can limit inspection. At Battelle, innovative electromagnetic sensors are being designed and tested for these new pipeline crawlers. The various sensor types can be used to assess a wide range of pipeline anomalies including corrosion, mechanical damage, and cracks. Battelle has completed the second year of work on a projected three-year development effort. In the first year, two innovative electromagnetic inspection technologies were designed and tested. Both were based on moving high-strength permanent magnets to generate inspection energy. One system involved translating permanent magnets towards the pipe. A pulse of electric current would be induced in the pipe to oppose the magnetization according to Lenz's Law. The decay of this pulse would indicate the presence of defects in the pipe wall. This inspection method is similar to pulsed eddy current inspection methods, with the fundamental difference being the manner in which the current is generated. Details of this development effort were reported in the first semiannual report on this project. The second inspection methodology is based on rotating permanent magnets. The rotating exciter unit produces strong eddy currents in the pipe wall. At distances of a pipe diameter or more from the rotating exciter, the currents flow circumferentially. These circumferential currents are deflected by pipeline defects such as corrosion and axially aligned cracks. Simple sensors are used to detect the change in current densities in the pipe wall. The

  2. INNOVATIVE ELECTROMAGNETIC SENSORS FOR PIPELINE CRAWLERS

    SciTech Connect

    J. Bruce Nestleroth

    2004-11-05

    Internal inspection of pipelines is an important tool for ensuring safe and reliable delivery of fossil energy products. Current inspection systems that are propelled through the pipeline by the product flow cannot be used to inspect all pipelines because of the various physical barriers they encounter. Recent development efforts include a new generation of powered inspection platforms that crawl slowly inside a pipeline and are able to maneuver past the physical barriers that can limit inspection. At Battelle, innovative electromagnetic sensors are being designed and tested for these new pipeline crawlers. The various sensor types can be used to assess a wide range of pipeline anomalies including corrosion, mechanical damage, and cracks. The Applied Energy Systems Group at Battelle is concluding the first year of work on a projected three-year development effort. In this first year, two innovative electromagnetic inspection technologies were designed and tested. Both were based on moving high-strength permanent magnets to generate inspection energy. One system involved translating permanent magnets towards the pipe. A pulse of electric current would be induced in the pipe to oppose the magnetization according to Lenz's Law. The decay of this pulse would indicate the presence of defects in the pipe wall. This inspection method is similar to pulsed eddy current inspection methods, with the fundamental difference being the manner in which the current is generated. Details of this development effort were reported in the first semiannual report on this project. This second semiannual report focuses on the development of a second inspection methodology, based on rotating permanent magnets. During this period, a rotating permanent magnet exciter was designed and built. The exciter unit produces strong eddy currents in the pipe wall. The tests have shown that at distances of a pipe diameter or more, the currents flow circumferentially, and that these circumferential

  3. Tractor Mechanic--Teacher's Guide. Competency Based Education Curriculum.

    ERIC Educational Resources Information Center

    McCann, Edward W.

    This teacher's guide is designed to accompany the Tractor Mechanic Competency Based Education (CBE) Curriculum (CE 022 480). The following information is included: a discussion of the uses of the Tractor Mechanic CBE curriculum; definitions of related terms; the table of contents for the Tractor Mechanic CBE curriculum; a list of competencies by…

  4. Effectiveness of the Indiana 4-H Tractor Program: Alumni Perceptions.

    ERIC Educational Resources Information Center

    Carrabba, James J., Jr.; Talbert, B. Allen; Field, William E.; Tormoehlen, Roger

    2001-01-01

    Responses from Indiana 4-H tractor driving contestants 1982-197 (n=139) showed that 74% were employed on farms; most felt the contests effectively taught tractor safety and made them generally aware of safety. However, many still engaged in risky behaviors such as not wearing seatbelts in tractors with rollover protective structures or allowing…

  5. Tractor Mechanics: Learning Activity Packages 1-19.

    ERIC Educational Resources Information Center

    Clemson Univ., SC. Vocational Education Media Center.

    Learning activity packages are presented for teaching tractor mechanics. The first of two sections deals with miscellaneous tasks and contains learning activity packages on cleaning the tractor and receiving new tractor parts. Section 2 is concerned with maintaining and servicing the electrical system, and it includes the following learning…

  6. 30 CFR 77.409 - Shovels, draglines, and tractors.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Shovels, draglines, and tractors. 77.409... COAL MINES Safeguards for Mechanical Equipment § 77.409 Shovels, draglines, and tractors. (a) Shovels, draglines, and tractors shall not be operated in the presence of any person exposed to a hazard from...

  7. Evaluation of mechanical tractor pedal extensions.

    PubMed

    Kelso, S A; Stangherlin, A M; Mann, D D

    2008-10-01

    Many farmers with disabilities choose to modify their work environments to accommodate their personal abilities; however, modified tractors may present greater risk to the operator as they are often one-of-a-kind designs that have not been subjected to rigorous safety testing. The objective of this research was to evaluate mechanical tractor pedal , extensions from a safety perspective. This objective was achieved by identifying potential hazards associated with the introduction of a pedal extension into the cab environment so that both existing and novel designs could be compared using a common methodology. Based on review of the published literature, 19 potential hazards associated with the introduction of a pedal extension into the cab of a tractor were identified. A hazard self-assessment worksheet (HSAW), created based on the 19 hazards, was validated through a pilot study. The overall inter-rater reliability and concurrent criterion validity proved to be acceptable. With the use of the HSAW six pedal extensions (three existing designs and three novel designs) were evaluated by 14 experts. Statistical analysis of the results did not identify a "best" design; however, several important trends were observed. Four of the six designs tended to block access to the exit path. The two designs that did not block access to the exit path might be considered to be the best designs for the tractors used in this study, but other designs likely would have been acceptable if they had been custom-fit for these tractors. The results of this research suggest that custom fabrication of pedal extensions for each specific tractor will likely yield the safest work environment for those who choose to use this assistive technology. PMID:19044171

  8. Workmen and Crawler Crane pouring roof slab and parapet wall ...

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

    Workmen and Crawler Crane pouring roof slab and parapet wall of building - looking northwest. Taken Nov. 15, 1929. 14th Naval District Photo Collection Item No. 7165 - U.S. Naval Base, Pearl Harbor, Exterior Cranes, Waterfront Crane Track System, Pearl City, Honolulu County, HI

  9. 29 CFR 1910.180 - Crawler locomotive and truck cranes.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 5 2013-07-01 2013-07-01 false Crawler locomotive and truck cranes. 1910.180 Section 1910.180 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR OCCUPATIONAL SAFETY AND HEALTH STANDARDS Materials Handling and Storage §...

  10. The Organization of Wariness of Heights in Experienced Crawlers

    ERIC Educational Resources Information Center

    Ueno, Mika; Uchiyama, Ichiro; Campos, Joseph J.; Dahl, Audun; Anderson, David I.

    2012-01-01

    Most infants with more than 6 weeks of crawling experience completely avoid the deep side of a visual cliff (Campos, Bertenthal, & Kermoian, 1992; Gibson & Walk, 1960). However, some experienced crawlers do move onto the transparent surface suspended several feet above the ground. An important question is whether these "nonavoiders" lack wariness…

  11. The Tractor Electrical System. A Teaching Reference.

    ERIC Educational Resources Information Center

    American Association for Vocational Instructional Materials, Athens, GA.

    The fundamental principles underlying the application of electricity to tractors and farm equipment are presented. An understanding of the material in the basic manual will enable the service man to understand better the service procedures covered in service manuals on electrical equipment. Topics dealt with are fundamentals of electricity,…

  12. Polyhedron tracking and gravity tractor asteroid deflection

    NASA Astrophysics Data System (ADS)

    Ummen, N.; Lappas, V.

    2014-11-01

    In the wake of the Chelyabinsk airburst, the defense against hazardous asteroids is becoming a topic of high interest. This work improves the gravity tractor asteroid deflection approach by tracking realistic small body shapes with tilted ion engines. An algorithm for polyhedron tracking was evaluated in a fictitious impact scenario. The simulations suggest a capability increase up to 38.2% with such improved tilting strategies. The long- and short-term effects within polyhedron tracking are illustrated. In particular, the orbital reorientation effect is influential when realistic asteroid shapes and rotations are accounted for. Also analyzed is the subject of altitude profiles, a way to tailor the gravity tractor performance, and to achieve a steering ability within the B-plane. A novel analytical solution for the classic gravity tractor is derived. It removes the simulation need for classic tractor designs to obtain comparable two body model Δv figures. This paper corroborates that the asteroid shape can be exploited for maximum performance. Even a single engine tilt adjustment at the beginning of deflection operations yields more deflection than a fixed preset tilt.

  13. V-TECS Guide for Tractor Mechanic.

    ERIC Educational Resources Information Center

    Benson, Robert T.

    This guide contains a course outline for a tractor mechanic course. The outline is organized by 15 duties: performing general skills and maintaining and servicing storage battery, ignition circuit, the cooling system, the charging circuit, the starting circuit, gasoline fuel system, diesel fuel system, basic engine, lubrication system, clutches,…

  14. Tractor Mechanic Check Sheets for Modules.

    ERIC Educational Resources Information Center

    Clemson Univ., SC. Vocational Education Media Center.

    Forms for student self-checks and the instructor's final checklist (student evaluation) are provided for use with thirty-three learning modules on maintaining and servicing fuel and electrical systems in tractor mechanics. The student self-check asks the students questions about their understanding of the modules' content. The instructor's…

  15. Tractor Trailer Driver's Training Programs. Performance Report.

    ERIC Educational Resources Information Center

    New Hampshire Vocational Technical Coll., Nashua.

    This document describes a project to develop a 320-hour tractor trailer driver training program and a 20-hour commercial driver licensing upgrade training program. Of 34 graduates from the training program, 28 secured employment in the trucking industry. From August 1989 to June 1990, 725 students were trained in the upgrade training program with…

  16. Plans for Learning Stations. Tractor Mechanics.

    ERIC Educational Resources Information Center

    Clemson Univ., SC. Vocational Education Media Center.

    This shop guide gives graphic illustration of twenty-eight learning stations in a tractor mechanics shop, at each of which a specific learning activity occurs. The authors suggest that each station (most of them constructed of plywood or sheet metal and angle iron) be self-contained, having its own appropriate tools, supplies, parts, and set of…

  17. INNOVATIVE ELECTROMAGNETIC SENSORS FOR PIPELINE CRAWLERS

    SciTech Connect

    J. Bruce Nestleroth; Richard J. Davis

    2005-05-23

    Internal inspection of pipelines is an important tool for ensuring safe and reliable delivery of fossil energy products. Current inspection systems that are propelled through the pipeline by the product flow cannot be used to inspect all pipelines because of the various physical barriers they encounter. Recent development efforts include a new generation of powered inspection platforms that crawl slowly inside a pipeline and are able to maneuver past the physical barriers that can limit inspection. At Battelle, innovative electromagnetic sensors are being designed and tested for these new pipeline crawlers. The various sensor types can be used to assess a wide range of pipeline anomalies including corrosion, mechanical damage, and cracks. The Applied Energy Systems Group at Battelle is in the second year of work on a projected three-year development effort. In the first year, two innovative electromagnetic inspection technologies were designed and tested. Both were based on moving high-strength permanent magnets to generate inspection energy. One system involved translating permanent magnets towards the pipe. A pulse of electric current would be induced in the pipe to oppose the magnetization according to Lenz's Law. The decay of this pulse would indicate the presence of defects in the pipe wall. This inspection method is similar to pulsed eddy current inspection methods, with the fundamental difference being the manner in which the current is generated. Details of this development effort were reported in the first semiannual report on this project. The second inspection methodology is based on rotating permanent magnets. The rotating exciter unit produces strong eddy currents in the pipe wall. At distances of a pipe diameter or more from the rotating exciter, the currents flow circumferentially. These circumferential currents are deflected by pipeline defects such as corrosion and axially aligned cracks. Simple sensors are used to detect the change in current

  18. Innovative Electromagnetic Sensors for Pipeline Crawlers

    SciTech Connect

    J. Bruce Nestleroth

    2006-05-04

    Internal inspection of pipelines is an important tool for ensuring safe and reliable delivery of fossil energy products. Current inspection systems that are propelled through the pipeline by the product flow cannot be used to inspect all pipelines because of the various physical barriers they encounter. Recent development efforts include a new generation of powered inspection platforms that crawl slowly inside a pipeline and are able to maneuver past the physical barriers that can limit inspection. At Battelle, innovative electromagnetic sensors are being designed and tested for these new pipeline crawlers. The various sensor types can be used to assess a wide range of pipeline anomalies including corrosion, mechanical damage, and cracks. Battelle is in the final year on a projected three-year development effort. In the first year, two innovative electromagnetic inspection technologies were designed and tested. Both were based on moving high-strength permanent magnets to generate inspection energy. One system involved translating permanent magnets towards the pipe. A pulse of electric current would be induced in the pipe to oppose the magnetization according to Lenz's Law. The decay of this pulse would indicate the presence of defects in the pipe wall. This inspection method is similar to pulsed eddy current inspection methods, with the fundamental difference being the manner in which the current is generated. Details of this development effort were reported in the first semiannual report on this project. The second inspection methodology is based on rotating permanent magnets. The rotating exciter unit produces strong eddy currents in the pipe wall. At distances of a pipe diameter or more from the rotating exciter, the currents flow circumferentially. These circumferential currents are deflected by pipeline defects such as corrosion and axially aligned cracks. Simple sensors are used to detect the change in current densities in the pipe wall. The second semiannual

  19. Texture descriptor combining fractal dimension and artificial crawlers

    NASA Astrophysics Data System (ADS)

    Gonçalves, Wesley Nunes; Machado, Bruno Brandoli; Bruno, Odemir Martinez

    2014-02-01

    Texture is an important visual attribute used to describe images. There are many methods available for texture analysis. However, they do not capture the detail richness of the image surface. In this paper, we propose a new method to describe textures using the artificial crawler model. This model assumes that agents can interact with the environment and each other. Since this swarm system alone does not achieve a good discrimination, we developed a new method to increase the discriminatory power of artificial crawlers, together with the fractal dimension theory. Here, we estimated the fractal dimension by the Bouligand-Minkowski method due to its precision in quantifying structural properties of images. We validate our method on two texture datasets and the experimental results reveal that our method leads to highly discriminative textural features. The results indicate that our method can be used in different texture applications.

  20. Artificial crawler model for texture analysis on silk fibroin scaffolds

    NASA Astrophysics Data System (ADS)

    Brandoli Machado, Bruno; Nunes Gonçalves, Wesley; Martinez Bruno, Odemir

    2014-01-01

    Texture plays an important role in computer vision tasks. Several methods of texture analysis are available. However, these methods are not capable of extracting rich detail in images. This paper presents a novel approach to image texture classification based on the artificial crawler model. Here, we propose a new rule of movement that moves artificial crawler agents not only toward higher intensities but also toward lower ones. This strategy is able of capturing more detail because the agents explore the peaks as well as the valleys. Thus, compared with the state-of-the-art method, this approach shows an increased discriminatory power. Experiments on the most well known benchmark demonstrate the superior performance of our approach. We also tested our approach on silk fibroin scaffold analysis, and results indicate that our method is consistent and can be applied in real-world situations.

  1. Tractor beam in micro-scale

    NASA Astrophysics Data System (ADS)

    Brzobohatý, O.; Karásek, V.; Šiler, M.; Chvátal, L.; Čižmár, T.; Zemánek, P.

    2014-12-01

    Following the Keplerian idea of radiative forces one would intuitively expect that an object illuminated by sunlight radiation or a laser beam is accelerated along the direction of the photon flow. Such radiation pressure forms the basis for the concept of solar sail, or laser acceleration of micro-particles. In contrast, a hypothetical optical field known from the realm of science-fiction as the "tractor" beam attracts the matter from large distances against the beam propagation. We present a geometry of such"tractor" beam in micro-scale and experimentally demonstrate how it acts upon spherical micro-particles of various sizes or optically self-arranged structures of micro-particles.

  2. Electrostatic Tractor Analysis for GEO Debris Remediation

    NASA Astrophysics Data System (ADS)

    Hogan, Erik A.

    The high value of operating in the geostationary ring, coupled with increasing numbers of orbital debris, highlights the need for GEO debris remediation techniques. One recent proposed technique for GEO debris mitigation is the electrostatic tractor. Here, a tug vehicle approaches a target debris object and emits a focused electron beam onto it. This results in a negative charge on the debris, and a positive charge on the tug vehicle. Due to the near proximity of the highly charged objects (20 meters or less) an attractive electrostatic force on the order of milliNewtons results. This electrostatic force is used in conjunction with low thrusting by the tug vehicle to tow the debris object into a disposal orbit 200-300 kilometers above the GEO belt. During the tugging period, the charged relative motion between tug and deputy is stabilized through a feedback control law. This is accomplished using a novel relative motion description that isolates separation distance from the relative orientation. The equations of motion for the relative motion description are derived from the Clohessy-Wiltshire equations, assuming the debris object is in a nearly circular orbit. Lyapunov stability theory is used to derive an asymptotically stable control law for the tug thrusters during the towing period. The control law requires an estimate of the electrostatic force magnitude, and the impacts of improperly modeled charging on control response are determined. If the electrostatic force is under-predicted too severely, a collision may result. A bound on the control gains is determined to prevent such a collision. Expected reorbiting performance levels achievable with the electrostatic tractor are computed. An open-loop analytical performance study is performed where variational equations are used to predict how much general orbital elements may be changed using the electrostatic tractor over one orbital period for a towed object at geosynchronous altitude. In contrast to earlier

  3. 78 FR 42800 - Certain Crawler Cranes and Components Thereof; Institution of Investigation Pursuant to United...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-17

    ... COMMISSION Certain Crawler Cranes and Components Thereof; Institution of Investigation Pursuant to United... 337 of the Tariff Act of 1930, as amended, 19 U.S.C. 1337, on behalf of Manitowoc Cranes, LLC of... certain crawler cranes and components thereof by reason of infringement of U.S. Patent No....

  4. 78 FR 36572 - Certain Crawler Cranes and Components Thereof Notice of Receipt of Complaint; Solicitation of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-18

    ... COMMISSION Certain Crawler Cranes and Components Thereof Notice of Receipt of Complaint; Solicitation of... entitled Certain Crawler Cranes and Components Thereof, DN 2960; the Commission is soliciting comments on... Commission's Rules of Practice and Procedure filed on behalf of Manitowoc Cranes, LLC on June 12, 2013....

  5. 78 FR 69448 - Agency Information Collection Activities; Submission for OMB Review; Comment Request; Crawler...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-19

    ..., 2013, (78 FR 33860). Interested parties are encouraged to send comments to the OMB, Office of...; Crawler, Locomotive, and Truck Cranes Standard ACTION: Notice. SUMMARY: The Department of Labor (DOL) is... (ICR) titled, ``Crawler, Locomotive, and Truck Cranes Standard,'' to the Office of Management...

  6. Single wheel testers, single track testers, and instrumented tractors

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Single wheel testers and single track testers are used for determining tractive performance characteristics of tires and tracks. Instrumented tractors are useful in determining the tractive performance of tractors. These machines are also used for determining soil-tire and soil-track interactions,...

  7. Agricultural Tractor Safety on Public Roads and Farms.

    ERIC Educational Resources Information Center

    Department of Transportation, Washington, DC.

    This study investigated the extent, causes, and means of preventing agricultural tractor accidents. The report includes an estimate of annual tractor-related deaths, an identification of the primary causes of such accidents with consideration of the major hazards causing death or injury, and recommendations or means for preventing the occurrence…

  8. Farm Tractor Tune-Up and Service Specifications.

    ERIC Educational Resources Information Center

    Bryant, J. G.; And Others

    Tune-up and service specifications for 10 major tractor manufacturers are presented in the handbook. In addition, the following tables are included: (1) spark plug heat-range comparisons, (2) freezing protection, (3) pressures for farm tractor tires, (4) use of calcium chloride for liquid weighting, (5) comparisons of American Petroleum Institute…

  9. MTR MAIN FLOOR. MTR TRACTOR IS IN CENTER OF VIEW ...

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

    MTR MAIN FLOOR. MTR TRACTOR IS IN CENTER OF VIEW AMIDST AN ACCUMULATION OF CLUTTER ON THE FLOOR. TRACTOR HAD ATTACHMENTS IN FRONT TO FACILITATE MOVING OF COFFINS. INL NEGATIVE NO. 56-3027. Jack L. Anderson, Photographer, 9/17/1956 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  10. Development of a small high-thrust tractor rocket motor

    SciTech Connect

    Carr, C.E.; Oberlander, W.F.

    1986-01-01

    This paper summarizes the parachute extraction tractor rocket motor design and test efforts conducted during the Sandia ASW/SOW development program. The prime contractor was Sandia National Laboratories, Albuquerque, New Mexico; the tractor rocket motor subcontractor was Morton Thiokol, Inc., Elkton, Maryland.

  11. Perceptions of tilt angles of an agricultural tractor.

    PubMed

    Görücü, Serap; Cavallo, Eugenio; Murphy, Dennis

    2014-01-01

    A tractor stability simulator has been developed to help study tractor operators' perceptions of angles when the simulator is tilted to the side. The simulator is a trailer-mounted tractor cab equipped with hydraulic lift that can tilt the tractor cabin up to 30 degrees. This paper summarizes data from 82 participants who sat in the simulator while it was tilted. Demographic variables, estimates of tilt angles, and measured tilt angles were collected. The effects of age, gender, tractor driving experience, and frequency of operation on the estimated and measured tilt angles were analyzed. The results showed that about 50% of the participants reported estimations of side tilt angles within ±5 degrees of the actual angles, and nearly the same percentage overestimated the actual side tilt angles. Only a small percentage underestimated the angles. Older, more experienced, and male participants set higher limits on the actual angle at which they felt uncomfortable and would not drive. PMID:24417527

  12. Enhanced Gravity Tractor Technique for Planetary Defense

    NASA Technical Reports Server (NTRS)

    Mazanek, Daniel D.; Reeves, David M.; Hopkins, Joshua B.; Wade, Darren W.; Tantardini, Marco; Shen, Haijun

    2015-01-01

    Given sufficient warning time, Earth-impacting asteroids and comets can be deflected with a variety of different "slow push/pull" techniques. The gravity tractor is one technique that uses the gravitational attraction of a rendezvous spacecraft to the impactor and a low-thrust, high-efficiency propulsion system to provide a gradual velocity change and alter its trajectory. An innovation to this technique, known as the Enhanced Gravity Tractor (EGT), uses mass collected in-situ to augment the mass of the spacecraft, thereby greatly increasing the gravitational force between the objects. The collected material can be a single boulder, multiple boulders, regolith or a combination of different sources. The collected mass would likely range from tens to hundreds of metric tons depending on the size of the impactor and warning time available. Depending on the propulsion system's capability and the mass collected, the EGT approach can reduce the deflection times by a factor of 10 to 50 or more, thus reducing the deflection times of several decades to years or less and overcoming the main criticism of the traditional gravity tractor approach. Additionally, multiple spacecraft can orbit the target in formation to provide the necessary velocity change and further reduce the time needed by the EGT technique to divert hazardous asteroids and comets. The robotic segment of NASA's Asteroid Redirect Mission (ARM) will collect a multi-ton boulder from the surface of a large Near-Earth Asteroid (NEA) and will provide the first ever demonstration of the EGT technique and validate one method of collecting in-situ mass on an asteroid of hazardous size.

  13. Development of the Safe Tractor Assessment Rating System.

    PubMed

    Day, L; Scott, M; Williams, R; Rechnitzer, G; Walsh, P; Boyle, S

    2005-08-01

    We describe the development of the Safe Tractor Assessment and Rating System (STARS), a design-based tractor safety rating system that can be applied to new or used tractors to provide an objective assessment of their inherent safety features. A predictive rating system model, based on technical inspection, was used. Key principles underlying the system included the potential for design features to reduce the risk of an injury event occurring, and to reduce the risk of injury if such an event did occur. The rating system was based on current standards, research literature, injury and fatality data, and farmer input via focus groups. Development was an iterative process involving field, pilot, and inter-rater reliability tests. The final system was divided into six domains: rollover protection, runover protection, user protection, information and controls, pedestrian protection, and options. Within each domain, optimum design features were described for the common or serious potential injury risks, and a score was assigned for each feature. Scores were translated into a star rating, from zero stars for virtually no inherent safety features to five stars for the highest inherent safety, for each of the six domains. STARS distinguished well between older tractor models known to have few inherent safety features and newer tractor models known to have higher levels of inherent safety. STARS can provide tractor manufacturers, dealers, and users with information critical for managing tractor-associated injury risk. In Australia, it is initially being implemented within the curriculum of the technical education and training sector. PMID:16184794

  14. A Simple Method to Improve Autonomous GPS Positioning for Tractors

    PubMed Central

    Gomez-Gil, Jaime; Alonso-Garcia, Sergio; Gómez-Gil, Francisco Javier; Stombaugh, Tim

    2011-01-01

    Error is always present in the GPS guidance of a tractor along a desired trajectory. One way to reduce GPS guidance error is by improving the tractor positioning. The most commonly used ways to do this are either by employing more precise GPS receivers and differential corrections or by employing GPS together with some other local positioning systems such as electronic compasses or Inertial Navigation Systems (INS). However, both are complex and expensive solutions. In contrast, this article presents a simple and low cost method to improve tractor positioning when only a GPS receiver is used as the positioning sensor. The method is based on placing the GPS receiver ahead of the tractor, and on applying kinematic laws of tractor movement, or a geometric approximation, to obtain the midpoint position and orientation of the tractor rear axle more precisely. This precision improvement is produced by the fusion of the GPS data with tractor kinematic control laws. Our results reveal that the proposed method effectively reduces the guidance GPS error along a straight trajectory. PMID:22163917

  15. A simple method to improve autonomous GPS positioning for tractors.

    PubMed

    Gomez-Gil, Jaime; Alonso-Garcia, Sergio; Gómez-Gil, Francisco Javier; Stombaugh, Tim

    2011-01-01

    Error is always present in the GPS guidance of a tractor along a desired trajectory. One way to reduce GPS guidance error is by improving the tractor positioning. The most commonly used ways to do this are either by employing more precise GPS receivers and differential corrections or by employing GPS together with some other local positioning systems such as electronic compasses or Inertial Navigation Systems (INS). However, both are complex and expensive solutions. In contrast, this article presents a simple and low cost method to improve tractor positioning when only a GPS receiver is used as the positioning sensor. The method is based on placing the GPS receiver ahead of the tractor, and on applying kinematic laws of tractor movement, or a geometric approximation, to obtain the midpoint position and orientation of the tractor rear axle more precisely. This precision improvement is produced by the fusion of the GPS data with tractor kinematic control laws. Our results reveal that the proposed method effectively reduces the guidance GPS error along a straight trajectory. PMID:22163917

  16. Narrow-track wheeled agricultural tractor parameter variation.

    PubMed

    Guzzomi, A; Rondelli, V

    2013-10-01

    Despite a general consensus among farmers, manufacturers, and researchers that wheeled agricultural tractor design has changed over time, there is little published evidence. There is debate as to whether the standardized rollover protective structure (ROPS) energy and force requirements, based on a tractor reference mass and pertaining to studies conducted more than 40 years ago, are appropriate for modern tractors. This article investigated the physical parameters of 326 modern narrow-track tractors, measured according to OECD Code 6 over 16 years (1993 to 2008 inclusive): 252 (-77%) were fixed-chassis tractors and 74 (-23%) were articulated. To understand the significance of design changes, the data were analyzed with respect to time and as a function of tractor mass. Articulated and fixed-chassis data were treated separately. The time data allowed qualitative analysis, while the mass data allowed quantitative analysis. The parameters show some changes over time and clearly indicate differences between articulated and fixed-chassis types. The parameter changes, along with the differences between types, may have important safety ramifications for ROPS energy absorption requirements, and these aspects are discussed. Regression lines with R2 values were fitted to the mass-related data for fixed-chassis and articulated tractors to determine the suitability of fit. The mass relations also displayed differences between fixed-chassis and articulated tractors. Thus, the most significant recommendation from this study is that the standardized testing procedure for narrow-track wheeled agricultural tractor category should be split into two groups: fixed-chassis and articulated. PMID:24673034

  17. Tractor Mechanics. Maintaining and Servicing the Engine, Learning Activity Packages 78-89; Lubricating the Tractor, Learning Activity Packages 90-94; Painting the Tractor, Learning Activity Packages 95-96.

    ERIC Educational Resources Information Center

    Clemson Univ., SC. Vocational Education Media Center.

    This series of learning activity packages focuses on three areas of tractor mechanics: (1) maintaining and servicing the engine, (2) lubricating the tractor, and (3) painting the tractor. Each of the nineteen illustrated learning activity packages follows a typical format: introduction, directions, objectives, learning activities, tools and…

  18. DETAIL VIEW OF STEAM TRACTOR "OLD DINAH," LOOKING NORTHWEST. THIS ...

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

    DETAIL VIEW OF STEAM TRACTOR "OLD DINAH," LOOKING NORTHWEST. THIS STEAM TRACTOR WAS USED TO REPLACE THE HORSE WAGON TRAINS THAT CARRIED SUPPLIES AND CRUDE OIL THE 26 MILES FROM BEATTY, NEVADA TO KEANE WONDER. THE TRACTOR ONLY MADE ONE RUN IN 1909 BEFORE THE BOILER EXPLODED ENROUTE, AND IT WAS ABANDONED THERE ON THE TRAIL TODAY IT STANDS ON DISPLAY AT THE FURNACE CREEK RANCH IN DEATH VALLEY NATIONAL PARK, AS SEEN IN THE PHOTOGRAPH. - Keane Wonder Mine, Park Route 4 (Daylight Pass Cutoff), Death Valley Junction, Inyo County, CA

  19. [Ergonomic evaluation of assembly line of tractors].

    PubMed

    Dellera, L; Buratti, G

    2012-01-01

    In the assembly lines in the engineering sector, ever more guided by the theories of lean production, is increasingly important ergonomic factor working conditions to preserve the health of workers and ensuring the performance. This analysis has focused on the study of biomechanical and postural stress of work tasks of an assembly line of the tractor, characterized by different weights and volumes from that of the car. Comparison with the technical standard of EN 1005-4 has allowed the identification as the machining assembly of small components result in conditions of acceptability, while most of the other processes aren't reliable. The emergence of these problems pushed to find several ergonomic solutions including the development of a special reclining seat to enable a proper posture during the working. PMID:23405593

  20. Power transmission device for a tractor

    SciTech Connect

    Kato, Y.; Nishimura, S.; Kishizawa, Y

    1989-05-23

    A power transmission device is described for an engine-driven tractor having a transmission case mounted in a rear part thereof, a main shifting device and a secondary shifting device arranged in front-to-back longitudinally spaced relation within the transmission case, means for lifting agricultural machinery including a lower arm vertically swingably mounted to the transmission case and a differential shaft extending transversely of the transmission case for transmitting drive power from the engine to an axle, characterized by the differential shaft being disposed between the main shifting device and the secondary shifting device, and the lower arm being pivotably connected to the transmission case adjacent to the secondary shifting device and behind the differential shaft.

  1. 17. Photocopy of c. 1922 photograph of cane field tractor ...

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

    17. Photocopy of c. 1922 photograph of cane field tractor developed and patented by Mr. Arsenaud of Laurel Valley Plantation; Claiborne Toups, overseer, is standing on the left. - Laurel Valley Sugar Plantation, State Route 308, Thibodaux, Lafourche Parish, LA

  2. VIEW OF STACK WITH AUTOMOBILE AND TRACTOR REPAIR SHOP TO ...

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

    VIEW OF STACK WITH AUTOMOBILE AND TRACTOR REPAIR SHOP TO THE FAR RIGHT. WAREHOUSE WITH ITS RIDGELINE ROTARY VENTS TO RIGHT OF STACK. VIEW FROM THE WEST - Kekaha Sugar Company, Sugar Mill Building, 8315 Kekaha Road, Kekaha, Kauai County, HI

  3. Safe tractor access platforms: from guidance material to implementation.

    PubMed

    Day, L; Rechnitzer, G

    2004-08-01

    This article reports on the implementation of published guidelines for retrofitting tractors with safe access platforms, which were developed to reduce the risk of serious injuries and deaths associated with mounting and dismounting. Farmer interviews and engineering-based inspections of ten retrofitted tractors were conducted to gather information regarding benefits and disadvantages of the retrofitting and to assess the construction of the platforms. A scoring system was developed for platform retrofitting, and weighted scores between zero and ten were calculated for tractor access before and after retrofitting. Access was improved on all tractors, although to varying degrees. The average post-retrofit weighted score was 6.3 (range 2.6 to 9.7), compared with the pre-retrofit average of 0.9 (range 0.3 to 1.6). Five tractors received a post-retrofit score of 8.0 or higher. None of the lower-scoring tractors fully met the specifications for placement of the bottom step or rear wheel guard, two key characteristics for runover prevention. Other characteristics associated with a lower post-retrofit score included a low bottom step, high step rises, absence of colored nosing, and the front handrail space not being filled in. Platform retrofitting had little effect on tractor operations and substantially improved ease of access. This is the first published evaluation of a design-based solution for tractor runover injuries. This study shows that general guidelines for retrofitting of safe access platforms can be successfully applied. Mechanisms to increase adherence to the key criteria of bottom step positioning and rear wheel guarding should be included in future promotion. PMID:15461136

  4. Fatalities associated with farm tractor injuries: an epidemiologic study.

    PubMed

    Goodman, R A; Smith, J D; Sikes, R K; Rogers, D L; Mickey, J L

    1985-01-01

    Death certificates were used as a source of information to characterize fatalities associated with farm tractor injuries in Georgia for the period 1971-81. In this period, 202 tractor-associated fatalities occurred among residents of Georgia; 198 of these persons were males. The annual tractor-associated fatality rate for males based on the population of male farm residents was 23.6 per 100,000; rates of fatal injury increased with age for this population. Persons whose primary occupation was other than farming accounted for more than half of all tractor-associated deaths. Fatal injuries occurred throughout the year but predominantly during the planting and harvesting months. Injuries occurred throughout the day (7 a.m. to midnight), with a peak at 4 p.m. to 5 p.m. Most fatal injuries, 76 percent, resulted when tractors overturned. Fatalities were attributed to crushed chest, exsanguination, strangulation or asphyxia, drowning, and other injuries. Current safety standards for the operation of farm tractors are limited; rollover protective canopies are not required for farm owners or their family members. Descriptive epidemiologic information obtained from death certificates can be used to define injury determinants and to suggest approaches for the further study and prevention of specific types of injuries. PMID:3923543

  5. Tractor overturn concerns in Iowa: perspectives from the Keokuk county rural health study.

    PubMed

    Sanderson, W T; Madsen, M D; Rautiainen, R; Kelly, K M; Zwerling, C; Taylor, C D; Reynolds, S J; Stromquist, A M; Burmeister, L F; Merchant, J A

    2006-02-01

    Agriculture remains one of the most hazardous industries in the U.S., with tractor overturns producing the greatest number of agricultural machinery-related fatalities. Rollover protective structures (ROPS) and seatbelts effectively reduce tractor overturn deaths. However, a large proportion of tractors in use in American agriculture are older tractors without ROPS and seatbelts. This article describes the tractor-related responses from participants in a population-based study conducted in Keokuk County, Iowa. This study was designed to measure rural and agricultural adverse health and injury outcomes and their respective risk factors. Questionnaires were partially developed from well-documented national surveys. Questions about agricultural machinery use, presence of safety equipment on the machinery, work practices, and attitudes about farm safety were included. Study participants on farms who owned tractors had an average of 3.1 tractors with an average age of 27 years. Only 39% of the 665 tractors had ROPS. Tractor age was associated with the presence of ROPS; 84% of tractors manufactured after 1984 were ROPS-equipped, whereas only 3% of tractors manufactured before 1960 were ROPS-equipped. ROPS-equipped tractors were significantly more common on larger farms and households with higher income. Only 4% of the farmers reported that their tractors had seatbelts and they wore them when operating their tractors. The results of this study support the findings of other studies, which indicate that many older tractors without ROPS and seatbelts remain in use in American agriculture. Until a dramatic reduction in the number of tractors in the U.S. operated without ROPS and seatbelts is achieved, the annual incidence of 120 to 130 deaths associated with tractor overturns will persist. PMID:16536175

  6. The Influence of Tractor-Seat Height above the Ground on Lateral Vibrations

    PubMed Central

    Gomez-Gil, Jaime; Gomez-Gil, Francisco Javier; Martin-de-Leon, Rebeca

    2014-01-01

    Farmers experience whole-body vibrations when they drive tractors. Among the various factors that influence the vibrations to which the driver is exposed are terrain roughness, tractor speed, tire type and pressure, rear axle width, and tractor seat height above the ground. In this paper the influence of tractor seat height above the ground on the lateral vibrations to which the tractor driver is exposed is studied by means of a geometrical and an experimental analysis. Both analyses show that: (i) lateral vibrations experienced by a tractor driver increase linearly with tractor-seat height above the ground; (ii) lateral vibrations to which the tractor driver is exposed can equal or exceed vertical vibrations; (iii) in medium-size tractors, a feasible 30 cm reduction in the height of the tractor seat, which represents only 15% of its current height, will reduce the lateral vibrations by around 20%; and (iv) vertical vibrations are scarcely influenced by tractor-seat height above the ground. The results suggest that manufacturers could increase the comfort of tractors by lowering tractor-seat height above the ground, which will reduce lateral vibrations. PMID:25340448

  7. The influence of tractor-seat height above the ground on lateral vibrations.

    PubMed

    Gomez-Gil, Jaime; Gomez-Gil, Francisco Javier; Martin-de-Leon, Rebeca

    2014-01-01

    Farmers experience whole-body vibrations when they drive tractors. Among the various factors that influence the vibrations to which the driver is exposed are terrain roughness, tractor speed, tire type and pressure, rear axle width, and tractor seat height above the ground. In this paper the influence of tractor seat height above the ground on the lateral vibrations to which the tractor driver is exposed is studied by means of a geometrical and an experimental analysis. Both analyses show that: (i) lateral vibrations experienced by a tractor driver increase linearly with tractor-seat height above the ground; (ii) lateral vibrations to which the tractor driver is exposed can equal or exceed vertical vibrations; (iii) in medium-size tractors, a feasible 30 cm reduction in the height of the tractor seat, which represents only 15% of its current height, will reduce the lateral vibrations by around 20%; and (iv) vertical vibrations are scarcely influenced by tractor-seat height above the ground. The results suggest that manufacturers could increase the comfort of tractors by lowering tractor-seat height above the ground, which will reduce lateral vibrations. PMID:25340448

  8. Mission Designs for Demonstrating Gravity Tractor Asteroid Deflection

    NASA Astrophysics Data System (ADS)

    Busch, M.; Faber, N.; Eggl, S.; Morrison, D.; Clark, A.; Frost, C.; Jaroux, B. A.; Khetawat, V.

    2015-12-01

    Gravity tractor asteroid deflection relies on the gravitational attraction between the target and a nearby spacecraft; using low-thrust propulsion to change the target's trajectory slowly but continuously. Our team, based at the NASA Ames Mission Design Center, prepared designs for a Gravity Tractor Demonstration Mission (GTDM) for the European Commission's NEOShield initiative. We found five asteroids with well-known orbits and opportunities for efficient stand-alone demonstrations in the 2020s. We selected one object, 2000 FJ10, for a detailed design analysis. Our GTDM design has a 4 kW solar-electric propulsion system and launch mass of 1150 kg. For a nominal asteroid mass of 3 x 109 kg and diameter 150 m, and a hovering altitude 125 m above the asteroid's surface, GTDM would change FJ10's semi-major axis by 10 km over 2 years. To measure the deflection clearly and to permit safe hovering by the spacecraft, several months of survey and characterization are required prior to the active tractoring phase of the mission. Accurate tracking is also required after the tractoring phase, to ensure that the asteroid has indeed been deflected as intended. The GTDM design includes both spacecraft and Earth-based observations of FJ10 to verify the deflection. The estimated cost of GTDM is $280 million. Trajectory analysis for GTDM confirmed that the outcome of a deflection of any asteroid depends on when that deflection is performed. Compared to kinetic impactor deflection, the gradual deflection from a gravity tractor produces comparable results for a given total momentum transfer. However, a gravity tractor can have greater flexibility in the direction in which the target asteroid can be deflected. Asteroid deflection scenarios must be modeled carefully on a case-to-case basis. We will review implications of the results of the GTDM study to other proposed gravity tractor demonstrations, such as that included in NASA's Asteroid Redirect Mission.

  9. Assessing farm tractor incidents and awareness levels of operators for tractor safety issues in the Hatay province of Turkey.

    PubMed

    Keskin, S Görücü; Keskin, M; Soysal, Y

    2012-04-01

    Studies and statistical data on safety issues related to farm tractors and machinery are very limited in developing countries, including Turkey. This study was carried out to investigate tractor-related incidents in the Hatay province, located in the mid-south of Turkey. A questionnaire was conducted with 107 tractor operators using face-to-face interviews. Data were evaluated according to the incident type, machinery involved, and mechanism of injury or fatality. A total of 101 incidents were reported by 77 of the 107 respondents. Most of the incidents were due to tractor rollovers (65.4%), 14.8% of the incidents were due to entanglement of body parts in moving machinery, and 12.9% involved crashing into other vehicles or obstacles. The leading cause of the incidents was personal mistakes (60.4%). Fatalities resulted from 25.7% of the incidents, while 45.5% of the incidents caused non-fatal injuries. Only 5.6% of the tractors had a ROPS-enclosed cab. The percentage of ROPS-equipped tractors was 19.6%, while 41.3% of the tractors had a shade cover and 33.6% had no protective structure. Only one of the respondents used a seatbelt, although 44.9% of them stated that seatbelts should be used. It was also found that only 13.5% of the operators had training in work safety, while 95.1% stated that incidents might be reduced if people were trained. Development of appropriate policies and training programs are needed for safer operation of agricultural machinery to reduce injuries and fatalities due to farm accidents. PMID:22655521

  10. 29 CFR 1926.1000 - Rollover protective structures (ROPS) for material handling equipment.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., rubber-tired dozers, wheel-type agricultural and industrial tractors, crawler tractors, crawler-type... requirement does not apply to sideboom pipelaying tractors. (2) The promulgation of specific standards...

  11. 49 CFR 393.61 - Truck and truck tractor window construction.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 5 2010-10-01 2010-10-01 false Truck and truck tractor window construction. 393.61 Section 393.61 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL... and truck tractor window construction. Each truck and truck tractor (except trucks engaged in...

  12. 49 CFR 399.207 - Truck and truck-tractor access requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 5 2010-10-01 2010-10-01 false Truck and truck-tractor access requirements. 399... Vehicles § 399.207 Truck and truck-tractor access requirements. (a) General rule. Any person entering or exiting the cab or accessing the rear portion of a high profile COE truck or truck-tractor shall...

  13. 75 FR 2153 - Certificate of Alternative Compliance for the Tractor Tug FORTE

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-14

    ... SECURITY Coast Guard Certificate of Alternative Compliance for the Tractor Tug FORTE AGENCY: Coast Guard... was issued for the tractor tug FORTE as required by 33 U.S.C. 1605(c) and 33 CFR 81.18. DATES: The... Purpose The tractor tug FORTE will be used for offshore supply operations. The horizontal distance...

  14. 4-H Tractor Operator Program Teaches Employability Skills and Safety to Youth

    ERIC Educational Resources Information Center

    Barrett, Debra K.

    2013-01-01

    For Michigan State University Extension, the Berrien County 4-H Tractor Operator Program has provided tractor safety education to teens for over 30 years. The certification training satisfies current requirements for operation of a 20 PTO HP or greater agricultural tractor by 14- and 15-year-old youth employed on property "not" owned,…

  15. A survey of tractors and rollover protective structures in Washington State.

    PubMed

    Spielholz, P; Sjostrom, T; Clark, R E; Adams, D A

    2006-11-01

    A survey of farms in Washington State was conducted to determine tractor characteristics and the presence of rollover protective structures (ROPS) in a state with more inclusive rules on tractor retrofitting than federal regulations. A total of 544 valid surveys were completed from a proportional random sample across different types of farms. Responders indicated that 58% of tractors overall were equipped with ROPS, and 42% of the tractors without ROPS were exempt from the state rules. Seatbelts on tractors equipped with ROPS were reportedly used "sometimes" or more 30% of the time, and 17% of these tractors had no seatbelt installed. Tractors used for row crop farming were significantly more likely to be equipped with ROPS than those used for tree, vine, or hops farming. Older tractors were used for fewer hours, were less likely to be ROPS-equipped, and were less likely to be operated while wearing a seatbelt. The results were consistent with a positive effect of the Washington State ROPS requirements, demonstrated by the increased percentage of ROPS-equipped pre-1976 tractors, as compared to other states, and by the difference between ROPS-equipped tractors in exempt and non-exempt types of farming. The results point to the need for prevention activities to increase seatbelt use on ROPS-equipped tractors, and for further development of practical protection for tractors operating under overhead obstacles. PMID:17131952

  16. Design and Development of a Robotic Crawler for CANDU Fuel Channel Inspection

    NASA Astrophysics Data System (ADS)

    Shukla, Shivam

    For the design of a new robotic crawler drive unit for CANDU fuel channel inspection, a complete design and screening process was done in order to fulfil the objective of this research. A brief explanation of CANDU reactors is provided along with a discussion of the inspection systems that are currently in use. A study of some existing inspection systems is presented which was used for the development of the new robotic crawler design. A number of concepts were generated which underwent a screening process with the help of two design tools. With the help of these tools, a concept was chosen as the final design and details of it are presented. To demonstrate a proof-of-concept, the physical prototype of the robotic crawler was manufactured and assembled. A speed controller was implemented in the final design of the robotic crawler. A set of test procedures were performed on the final design and the results are discussed. Some improvements that can be done on the final design of the robotic crawler are also discussed in the final section of this thesis.

  17. 78 FR 33860 - Crawler, Locomotive, and Truck Cranes Standard; Extension of the Office of Management and Budget...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-05

    ... Secretary of Labor's Order No. 1-2012 (77 FR 3912). Signed at Washington, DC, on May 31, 2013. David... Occupational Safety and Health Administration Crawler, Locomotive, and Truck Cranes Standard; Extension of the... Standard on Crawler, Locomotive, and Truck cranes (29 CFR 1910.180). DATES: Comments must be...

  18. 75 FR 20005 - Crawler, Locomotive, and Truck Cranes Standard; Extension of the Office of Management and Budget...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-16

    ... Paperwork Reduction Act of 1995 (44 U.S.C. 3506 et seq.) and Secretary of Labor's Order No. 5-2007 (72 FR... Occupational Safety and Health Administration Crawler, Locomotive, and Truck Cranes Standard; Extension of the... collection requirements contained in its Crawler, Locomotive, and Truck Cranes Standard (29 CFR...

  19. The Organization of Wariness of Heights in Experienced Crawlers

    PubMed Central

    Ueno, Mika; Uchiyama, Ichiro; Campos, Joseph J.; Dahl, Audun; Anderson, David I.

    2011-01-01

    Most infants with more than 6 weeks of crawling experience completely avoid the deep side of a visual cliff (Campos et al., 1992; Gibson & Walk, 1960). However, some experienced crawlers do move onto the transparent surface suspended several feet above the ground. An important question is whether these non-avoiders lack wariness of heights or whether they have a qualitatively different way of showing their wariness than do avoiders of the deep side. The current study addressed this question by measuring heart rate (HR) acceleration upon being lowered on the deep and shallow sides of the visual cliff, latency to crawl toward the mother, and tactile exploration of the cliff surface. Non-avoiders and avoiders had indistinguishable patterns of HR acceleration, showing greater HR acceleration when lowered onto the deep than when lowered onto the shallow side of the cliff. Non-avoiders also showed more tactile exploration and longer latencies than did a comparable group of infants tested on the shallow side. This study illustrates how the same emotion, wariness of heights, can be shown by qualitatively different behaviors, all serving the same function of protecting the individual from falling over a drop-off. PMID:24817830

  20. Creating a National Coalition to Address Tractor Overturn Fatalities.

    PubMed

    Tinc, P J; Ayers, P D; May, J J; Purschwitz, M A; Sorensen, J A

    2015-04-01

    Tractor overturns continue to be the leading cause of death on U.S. farms. While rollover protective structures (ROPS) are effective in preventing these fatalities, they are underutilized due to a number of barriers. Past programs in the U.S. and abroad have targeted this area of agricultural safety; however, a national program is not yet in place for U.S. farmers. This study seeks to build a national partnership to address tractor overturn fatalities by increasing the number of tractors with ROPS. A diverse, multisector steering committee has been organized and is working together using Whole System in a Room methods. This method brings together partners from nine stakeholder groups to identify and commit to a collaborative solution to the issue. PMID:26204786

  1. STS-101 Atlantis aboard the crawler-transporter on way to LC-39A

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Passing by a palm tree, the Space Shuttle Atlantis aboard the crawler-transporter makes its way to Launch Pad 39A. The crawler- transporter carries its cargo at 1 mph, taking about five hours to cover the 3.4 miles from the Vehicle Assembly Building to the launch pad. A leveling system on the crawler-transporter keeps the top of the Space Shuttle vertical, especially negotiating the ramp leading to the launch pads and when it is raised and lowered on pedestals at the pad. Liftoff of Atlantis on mission STS-101 is scheduled for April 17 at 7:03 p.m. EDT. STS-101 is a logistics and resupply mission for the International Space Station, to restore full redundancy to the International Space Station power system in preparation for the arrival of the next pressurized module, the Russian-built Zvezda.

  2. STS-101 Atlantis aboard the crawler-transporter on way to LC-39A

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Just after departing the Vehicle Assembly Building, the Space Shuttle Atlantis aboard the crawler-transporter wends its way to Launch Pad 39A. The crawler-transporter carries its cargo at 1 mph, taking about five hours to cover the 3.4 miles from the Vehicle Assembly Building to the launch pad. A leveling system on the crawler-transporter keeps the top of the Space Shuttle vertical, especially negotiating the ramp leading to the launch pads and when it is raised and lowered on pedestals at the pad. Liftoff of Atlantis on mission STS-101 is scheduled for April 17 at 7:03 p.m. EDT. STS-101 is a logistics and resupply mission for the International Space Station, to restore full redundancy to the International Space Station power system in preparation for the arrival of the next pressurized module, the Russian-built Zvezda.

  3. STS-101 Atlantis aboard the crawler-transporter approaches LC-39A

    NASA Technical Reports Server (NTRS)

    2000-01-01

    The Space Shuttle Atlantis, atop the mobile launcher platform and crawler-transporter, begins the climb up the ramp to Launch Pad 39A. The crawler-transporter carries its cargo at 1 mph, taking about five hours to cover the 3.4 miles from the Vehicle Assembly Building to the launch pad. A leveling system on the crawler- transporter keeps the top of the Space Shuttle vertical, especially negotiating the ramp leading to the launch pads and when it is raised and lowered on pedestals at the pad. Liftoff of Atlantis on mission STS-101 is scheduled for April 17 at 7:03 p.m. EDT. STS-101 is a logistics and resupply mission for the International Space Station, to restore full redundancy to the International Space Station power system in preparation for the arrival of the next pressurized module, the Russian-built Zvezda.

  4. Mission Concepts and Operations for Asteroid Mitigation Involving Multiple Gravity Tractors

    NASA Technical Reports Server (NTRS)

    Foster, Cyrus; Bellerose, Julie; Jaroux, Belgacem; Mauro, David

    2012-01-01

    The gravity tractor concept is a proposed method to deflect an imminent asteroid impact through gravitational tugging over a time scale of years. In this study, we present mission scenarios and operational considerations for asteroid mitigation efforts involving multiple gravity tractors. We quantify the deflection performance improvement provided by a multiple gravity tractor campaign and assess its sensitivity to staggered launches. We next explore several proximity operation strategies to accommodate multiple gravity tractors at a single asteroid including formation-flying and mechanically-docked configurations. Finally, we utilize 99942 Apophis as an illustrative example to assess the performance of a multiple gravity tractor campaign.

  5. A Spatial Cluster Analysis of Tractor Overturns in Kentucky from 1960 to 2002

    PubMed Central

    Saman, Daniel M.; Cole, Henry P.; Odoi, Agricola; Myers, Melvin L.; Carey, Daniel I.; Westneat, Susan C.

    2012-01-01

    Background Agricultural tractor overturns without rollover protective structures are the leading cause of farm fatalities in the United States. To our knowledge, no studies have incorporated the spatial scan statistic in identifying high-risk areas for tractor overturns. The aim of this study was to determine whether tractor overturns cluster in certain parts of Kentucky and identify factors associated with tractor overturns. Methods A spatial statistical analysis using Kulldorff's spatial scan statistic was performed to identify county clusters at greatest risk for tractor overturns. A regression analysis was then performed to identify factors associated with tractor overturns. Results The spatial analysis revealed a cluster of higher than expected tractor overturns in four counties in northern Kentucky (RR = 2.55) and 10 counties in eastern Kentucky (RR = 1.97). Higher rates of tractor overturns were associated with steeper average percent slope of pasture land by county (p = 0.0002) and a greater percent of total tractors with less than 40 horsepower by county (p<0.0001). Conclusions This study reveals that geographic hotspots of tractor overturns exist in Kentucky and identifies factors associated with overturns. This study provides policymakers a guide to targeted county-level interventions (e.g., roll-over protective structures promotion interventions) with the intention of reducing tractor overturns in the highest risk counties in Kentucky. PMID:22291980

  6. A spatial cluster analysis of tractor overturns in Kentucky from 1960 to 2002

    USGS Publications Warehouse

    Saman, D.M.; Cole, H.P.; Odoi, A.; Myers, M.L.; Carey, D.I.; Westneat, S.C.

    2012-01-01

    Background: Agricultural tractor overturns without rollover protective structures are the leading cause of farm fatalities in the United States. To our knowledge, no studies have incorporated the spatial scan statistic in identifying high-risk areas for tractor overturns. The aim of this study was to determine whether tractor overturns cluster in certain parts of Kentucky and identify factors associated with tractor overturns. Methods: A spatial statistical analysis using Kulldorff's spatial scan statistic was performed to identify county clusters at greatest risk for tractor overturns. A regression analysis was then performed to identify factors associated with tractor overturns. Results: The spatial analysis revealed a cluster of higher than expected tractor overturns in four counties in northern Kentucky (RR = 2.55) and 10 counties in eastern Kentucky (RR = 1.97). Higher rates of tractor overturns were associated with steeper average percent slope of pasture land by county (p = 0.0002) and a greater percent of total tractors with less than 40 horsepower by county (p<0.0001). Conclusions: This study reveals that geographic hotspots of tractor overturns exist in Kentucky and identifies factors associated with overturns. This study provides policymakers a guide to targeted county-level interventions (e.g., roll-over protective structures promotion interventions) with the intention of reducing tractor overturns in the highest risk counties in Kentucky. ?? 2012 Saman et al.

  7. Math on the Job. Tractor-Trailer Driver.

    ERIC Educational Resources Information Center

    Ohio State Univ., Columbus. National Center for Research in Vocational Education.

    This booklet is intended to help mainstreamed mentally retarded, emotionally disturbed, or learning disabled high school students acquire a basic understanding of the responsibilities and working conditions of tractor-trailer drivers and to practice basic math skills necessary in the occupation. The first section provides a brief introduction to…

  8. [The assessment of the vibration load in tractor drivers].

    PubMed

    Goranova, L; Ivanovich, E

    1990-01-01

    The assessment of the vibration loading of a group of tractor-drivers from the enterprise for melioration and erosion control is made on the basis of: measurement of general and local vibrations and noise of 5 tractors type C 100, C 100M and T 130; determination of the total vibration loading on the basis of data of measurements and average weekly hour individual engagement; comparison of the admissible values of vibration loading with the real determined at work with machines of different vibration characters at different hour engagement. A surpass of the admissible vibration loading is established which reaches up to 3.3 (at average weekly exposure to 30 hrs.) and to 4.7 hrs (at average weekly exposure 42.5 hrs.) with the tractors with higher surpass of MAC for the general vibrations. An admissible exposure for 1 day and for 1 year work for the separate tractors is determined in relation to the data for general and local vibrations and individual hour engagement. PMID:2099465

  9. 40 CFR 1037.630 - Special purpose tractors.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... under § 1037.135: “THIS VEHICLE WAS CERTIFIED AS A VOCATIONAL TRACTOR UNDER 40 CFR 1037.630.”. (4) You... § 1037.631 and using an engine certified to the standards of 40 CFR part 1036 are deemed to fully...

  10. 40 CFR 1037.630 - Special purpose tractors.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... under § 1037.135: “THIS VEHICLE WAS CERTIFIED AS A VOCATIONAL TRACTOR UNDER 40 CFR 1037.630.”. (4) You... § 1037.631 and using an engine certified to the standards of 40 CFR part 1036 are deemed to fully...

  11. 40 CFR 1037.630 - Special purpose tractors.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... under § 1037.135: “THIS VEHICLE WAS CERTIFIED AS A VOCATIONAL TRACTOR UNDER 40 CFR 1037.630.”. (4) You... § 1037.631 and using an engine certified to the standards of 40 CFR part 1036 are deemed to fully...

  12. Tractor Mechanic--Student Material. Competency Based Education Curriculum.

    ERIC Educational Resources Information Center

    McCann, Edward W.

    Developed to assist vocational agricultural mechanics students in learning to be tractor mechanics, this curriculum guide contains all the student competency sheets which comprise this competency-based curriculum. These competency sheets are categorized under sixteen instructional units. The first two units cover employment opportunities and…

  13. Operators' perception of comfort in two tractor cabs.

    PubMed

    Ferrari, E; Cavallo, E

    2013-01-01

    Workspace characteristics affect the perceived comfort level of the operator and uncomfortable working conditions have been found to have a negative impact on productivity and safety. The comfort of the operator is increasingly recognized by manufacturers as a product's added value. Comfort can positively distinguish a product and increase its competitiveness. The concept of comfort is controversial, and a clear operational definition is missing. Nevertheless, it is widely accepted that comfort is a subjective phenomenon that can be evaluated by the final users. In this study, comfort aspects of the tractor workspace interior (i.e., the cab) were investigated. Users with various levels of expertise and two medium-power utility tractors of different brands were used in a 2 x 2 mixed-factorial experimental design. Participants were involved in a dynamic assessment of the cabs, and their opinions about the different workspaces were collected through a questionnaire. Additionally, objective measurements were taken on both tractors, and subjective data were compared with objective data. Results indicate significant differences in terms of the ease of locating and operating the controls (i.e., rear-mounted three-point linkage, hydraulic system, and power take-off), the ease of starting the tractor, the ease exiting the cab, the required level of concentration in executing the tasks, the adequacy of lateral visibility from the driving station, and the level of noise at the operator's position. This article provides guidance for improving the comfort of tractor workspace interiors. Agricultural machinery manufactures would benefit from research results, differentiating themselves from competitors. PMID:23600166

  14. Design and experimental validation of a simple controller for a multi-segment magnetic crawler robot

    NASA Astrophysics Data System (ADS)

    Kelley, Leah; Ostovari, Saam; Burmeister, Aaron B.; Talke, Kurt A.; Pezeshkian, Narek; Rahimi, Amin; Hart, Abraham B.; Nguyen, Hoa G.

    2015-05-01

    A novel, multi-segmented magnetic crawler robot has been designed for ship hull inspection. In its simplest version, passive linkages that provide two degrees of relative motion connect front and rear driving modules, so the robot can twist and turn. This permits its navigation over surface discontinuities while maintaining its adhesion to the hull. During operation, the magnetic crawler receives forward and turning velocity commands from either a tele-operator or high-level, autonomous control computer. A low-level, embedded microcomputer handles the commands to the driving motors. This paper presents the development of a simple, low-level, leader-follower controller that permits the rear module to follow the front module. The kinematics and dynamics of the two-module magnetic crawler robot are described. The robot's geometry, kinematic constraints and the user-commanded velocities are used to calculate the desired instantaneous center of rotation and the corresponding central-linkage angle necessary for the back module to follow the front module when turning. The commands to the rear driving motors are determined by applying PID control on the error between the desired and measured linkage angle position. The controller is designed and tested using Matlab Simulink. It is then implemented and tested on an early two-module magnetic crawler prototype robot. Results of the simulations and experimental validation of the controller design are presented.

  15. Efficiency of goal-oriented communicating agents in different graph topologies: A study with Internet crawlers

    NASA Astrophysics Data System (ADS)

    Lőrincz, András; Lázár, Katalin A.; Palotai, Zsolt

    2007-05-01

    To what extent does the communication make a goal-oriented community efficient in different topologies? In order to gain insight into this problem, we study the influence of learning method as well as that of the topology of the environment on the communication efficiency of crawlers in quest of novel information in different topics on the Internet. Individual crawlers employ selective learning, function approximation-based reinforcement learning (RL), and their combination. Selective learning, in effect, modifies the starting URL lists of the crawlers, whilst RL alters the URL orderings. Real data have been collected from the web and scale-free worlds, scale-free small world (SFSW), and random world environments (RWEs) have been created by link reorganization. In our previous experiments [ Zs. Palotai, Cs. Farkas, A. Lőrincz, Is selection optimal in scale-free small worlds?, ComPlexUs 3 (2006) 158-168], the crawlers searched for novel, genuine documents and direct communication was not possible. Herein, our finding is reproduced: selective learning performs the best and RL the worst in SFSW, whereas the combined, i.e., selective learning coupled with RL is the best-by a slight margin-in scale-free worlds. This effect is demonstrated to be more pronounced when the crawlers search for different topic-specific documents: the relative performance of the combined learning algorithm improves in all worlds, i.e., in SFSW, in SFW, and in RWE. If the tasks are more complex and the work sharing is enforced by the environment then the combined learning algorithm becomes at least equal, even superior to both the selective and the RL algorithms in most cases, irrespective of the efficiency of communication. Furthermore, communication improves the performance by a large margin and adaptive communication is advantageous in the majority of the cases.

  16. Personal noise exposures of operators of agricultural tractors.

    PubMed

    Aybek, Ali; Kamer, H Atil; Arslan, Selçuk

    2010-03-01

    Approximately one million agricultural tractors are used in Turkey for crop production and about one-third of the population lives in rural areas. The objectives of this study were to determine sound pressure levels, A-weighted sound pressure levels, and the permissible exposure time for tractors without cabins, field-installed cabins, and original cabins at ear level of agricultural tractor operators for following machines: plows, cultivators, top soil cultivators, rotary tillers, tool combinations (harrow+roller), mechanical drills, pneumatic drills, chemical applicators, fertilizer applicators, drum mowers, balers, and forage harvesters. Variance analyses showed that type of operation, type of cabins, and operation x cabin interactions were statistically significant (P<0.01) both for sound pressure levels and equivalent (A-weighted) sound pressure levels. The use of original cabins had a greater effect in decreasing average sound pressures and resulted in more efficient noise insulation, especially at higher center frequencies compared to field-installed cabins whereas field-installed cabins proved to be more favorable compared to tractors without cabins. Sound pressure levels at 4000Hz center frequency was reduced 2-13dB and 4-18dB by using a field-installed cabin and an original cabin, respectively. The measured A-weighted equivalent sound pressure levels were compared to the threshold limit level, and was concluded that depending on the cabin types used, the operators could usually work from 4 to 6h a day without suffering from noise induced inconveniences while 2-3h is permissible for plowing and forage harvesting on tractors without cabins. Due to timeliness considerations in agricultural machine operations, a farmer would not be willing to interrupt the operation based on permissible exposure time set by the standards. Based on the findings of this study, particularly an original cabin is recommended to reduce machine-induced noise below the danger limit

  17. A long-range polarization-controlled optical tractor beam

    NASA Astrophysics Data System (ADS)

    Shvedov, Vladlen; Davoyan, Arthur R.; Hnatovsky, Cyril; Engheta, Nader; Krolikowski, Wieslaw

    2014-11-01

    The laser beam has become an indispensable tool for the controllable manipulation and transport of microscopic objects in biology, physical chemistry and condensed matter physics. In particular, ‘tractor’ laser beams can draw matter towards a laser source and perform, for instance, all-optical remote sampling. Recent advances in lightwave technology have already led to small-scale experimental demonstrations of tractor beams. However, the realization of long-range tractor beams has not gone beyond the realm of theoretical investigations. Here, we demonstrate the stable transfer of gold-coated hollow glass spheres against the power flow of a single inhomogeneously polarized laser beam over tens of centimetres. Additionally, by varying the polarization state of the beam we can stop the spheres or reverse the direction of their motion at will.

  18. Helical tractor beam: analytical solution of Rayleigh particle dynamics.

    PubMed

    Carretero, Luis; Acebal, Pablo; Garcia, Celia; Blaya, Salvador

    2015-08-10

    We analyze particle dynamics in an optical force field generated by helical tractor beams obtained by the interference of a cylindrical beam with a topological charge and a co-propagating temporally de-phased plane wave. We show that, for standard experimental conditions, it is possible to obtain analytical solutions for the trajectories of particles in such force field by using of some approximations. These solutions show that, in contrast to other tractor beams described before, the intensity becomes a key parameter for the control of particle trajectories. Therefore, by tuning the intensity value the particle can describe helical trajectories upstream and downstream, a circular trajectory in a fixed plane, or a linear displacement in the propagation direction. The approximated analytical solutions show good agreement to the corresponding numerical solutions of the exact dynamical differential equations. PMID:26367905

  19. Power takeoff for tractor having parallelogram front wheel suspension

    SciTech Connect

    Slazas, J.J.

    1986-11-11

    A tractor having a rigid frame under which a mower can be carried longitudinally intermediate rear driving wheels and steerable front wheels. The tractor comprises an engine mounted on a front portion of the frame, a rigid laterally extending support member near the front end of the frame, laterally opposite wheel supporting brackets, one pivoted to each end portion of the support member to swing about a longitudinally extending upper axis. The tractor also comprises a laterally extending link pivoted to each of the brackets on a lower axis that is below and parallel to the upper axis to cooperate with the support member in connecting the brackets in a parallelogram linkage, and an axle member for each bracket having a laterally inner portion pivoted to the bracket to swing about a substantially vertical axis and having a laterally outwardly extending axle portion on which a front wheel is rotatable. The tractor is characterized by: A. a tubular bushing secured to the support member intermediate the ends thereof with its axis extending longitudinally; B. a power takeoff shaft coaxially rotatable in the bushing having opposite end portions that respectively project forward and rearward beyond the bushing; C. a laterally extending hitch support having means near its opposite ends for detachable connection to it of forwardly projecting hitch members of a mower; D. a sleeve secured to the hitch support intermediate its ends and surrounding the bushing to pivot the hitch support for tilting about the axis of the bushing; E. a connection between the link and the hitch support whereby substantially lateral motion of the link imparts tilting motion to the hitch support; and F. a driving connection between the engine and one of the end portions of the shaft.

  20. System identification, adaptive control and formation driving of farm tractors

    NASA Astrophysics Data System (ADS)

    Rekow, Andrew Karl Wilhelm

    Great increases in agricultural productivity and profitability can be gained by increasing the navigational control accuracy of a farm tractor. To maximize accuracy in the presence of environmental uncertainties, a novel technique for on-line parameter identification has been developed. This method combines the Extended Kalman Filter (EKF) and the Least Mean Square (LMS) algorithms and is used to identify key parameters which describe the dynamics of a farm tractor. This algorithm provides a 15:1 improvement in computational efficiency over the traditional EKF, while offering comparable convergence rates and noise rejection properties. Experimental data on a full-sized John Deere tractor shows a 25 percent improvement in lateral accuracy when using then adaptive controller versus a fixed controller over identical trajectories. In addition to parameter identification, farmers require formation driving capability for routine operations. Multiple farm vehicles work cooperatively together to accomplish a common goal. Several formation driving algorithms were developed for these varying requirements. An experimental implementation of a fully autonomous farm vehicle following a human operated lead vehicle demonstrated an accuracy of 10 centimeters in the in-track direction and 10 centimeters in the cross track direction.

  1. Innovative Sensors for Pipeline Crawlers: Rotating Permanent Magnet Inspection

    SciTech Connect

    J. Bruce Nestleroth; Richard J. Davis; Stephanie Flamberg

    2006-09-30

    Internal inspection of pipelines is an important tool for ensuring safe and reliable delivery of fossil energy products. Current inspection systems that are propelled through the pipeline by the product flow cannot be used to inspect all pipelines because of the various physical barriers they may encounter. To facilitate inspection of these ''unpiggable'' pipelines, recent inspection development efforts have focused on a new generation of powered inspection platforms that are able to crawl slowly inside a pipeline and can maneuver past the physical barriers that limit internal inspection applicability, such as bore restrictions, low product flow rate, and low pressure. The first step in this research was to review existing inspection technologies for applicability and compatibility with crawler systems. Most existing inspection technologies, including magnetic flux leakage and ultrasonic methods, had significant implementation limitations including mass, physical size, inspection energy coupling requirements and technology maturity. The remote field technique was the most promising but power consumption was high and anomaly signals were low requiring sensitive detectors and electronics. After reviewing each inspection technology, it was decided to investigate the potential for a new inspection method. The new inspection method takes advantage of advances in permanent magnet strength, along with their wide availability and low cost. Called rotating permanent magnet inspection (RPMI), this patent pending technology employs pairs of permanent magnets rotating around the central axis of a cylinder to induce high current densities in the material under inspection. Anomalies and wall thickness variations are detected with an array of sensors that measure local changes in the magnetic field produced by the induced current flowing in the material. This inspection method is an alternative to the common concentric coil remote field technique that induces low-frequency eddy

  2. 29 CFR 1928.52 - Protective frames for wheel-type agricultural tractors-test procedures and performance requirements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... CFR 1928.51. (b) Types of tests. All protective frames for wheel-type agricultural tractors shall be... load is applied. (ii) The following definitions shall apply: W = Tractor weight (see 29 CFR 1928.51(a... conditions shall be met: (A) The protective frame and tractor shall be tested at the weight defined by 29...

  3. 29 CFR 1928.52 - Protective frames for wheel-type agricultural tractors-test procedures and performance requirements.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... CFR 1928.51. (b) Types of tests. All protective frames for wheel-type agricultural tractors shall be... load is applied. (ii) The following definitions shall apply: W = Tractor weight (see 29 CFR 1928.51(a... conditions shall be met: (A) The protective frame and tractor shall be tested at the weight defined by 29...

  4. 49 CFR 399.207 - Truck and truck-tractor access requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 5 2014-10-01 2014-10-01 false Truck and truck-tractor access requirements. 399... Vehicles § 399.207 Truck and truck-tractor access requirements. (a) General rule. Any person entering or... are accessible from the ground, no step, handholds or deck plates are required to permit access to...

  5. A Tractor or an Automobile? A 1920s Farm Family Faces a Decision.

    ERIC Educational Resources Information Center

    Kunze, Joel P.

    1991-01-01

    Outlines a lesson plan in which students role play a 1920s farm family deciding whether to buy an automobile or a tractor. Other students act as automobile and tractor sales groups. Explains how the lesson illuminates relationships between technological advance and social history. Includes handouts identifying benefits of purchasing cars or…

  6. Optimized optical "tractor beam" for core-shell nanoparticles.

    PubMed

    Wang, Neng; Lu, Wanli; Ng, Jack; Lin, Zhifang

    2014-04-15

    It is known that core-shell subwavelength nanoparticles consisting of a dielectric shell and a metallic core can simultaneously support electric and magnetic dipolar resonances, which enhance forward scattering and suppress backward scattering. This creates favorable conditions for optical tractor beam applications. Using the generalized Lorenz-Mie theory and Maxwell stress tensor formulation, we demonstrate how optical pulling forces can be induced and optimized by first-order Bessel beams with appropriate polarization. The transverse stability of the core-shell nanoparticle under ambient damping is also verified by linear stability analysis and dynamical simulation. PMID:24979003

  7. Retrofitting tractors with rollover protective structures: perspective of equipment dealers.

    PubMed

    Tonelli, S M; Donham, K J; Leedom-Larson, K; Sanderson, W; Purschwitz, M

    2009-10-01

    This study was one of a cluster of studies that originated via requests for proposals from the NIOSH National Agricultural Tractor Safety Initiative. The present study design consisted of several steps: (1) formation of an advisory group, (2) development and testing of a standard paper self-responding survey instrument, (3) sample selection of farm equipment dealers, (4) administration of the survey, (5) assessment and analysis of the survey, and (6) in-person response panel of dealers (n = 80) to review results of the questionnaire for further definition and sharpening of the recommendations from the survey. A key finding is that most dealers do not currently sell or install ROPS retrofit kits. Barriers cited by dealers included (1) actual or perceived lack of farmer demand, (2) injury liability, (3) expensive freight for ordering ROPS, (4) lack of dealer awareness of the magnitude of deaths from tractor overturns and the high life-protective factor of ROPS, and (5) difficulty and incursion of non-recoverable expenses in locating and obtaining specific ROPS. Despite not currently selling or installing ROPS, dealers responded favorably about their future potential role in ROPS promotion and sales. Dealers were willing to further promote, sell, and install ROPS if there was demand from farmers. Recommendations include establishing a ROPS "clearing house" that dealers could contact to facilitate locating and obtaining ROPS orders from customers. Additional recommendations include education and social marketing targeting farm machinery dealers as well farmers, manufacturers, and policy makers. PMID:19967910

  8. CO{sub 2} Laser Ablation Propulsion Tractor Beams

    SciTech Connect

    Sinko, John E.; Schlecht, Clifford A.

    2010-05-06

    Manipulation of objects at a distance has already been achieved with no small measure of success in the realm of microscopic objects on the scale size of nanometers to micrometers in applications including laser trapping and laser tweezers. However, there has been relatively little effort to apply such remote control to macroscopic systems. A space tractor beam could be applied to a wide range of applications, including removal of orbital debris, facilitation of spacecraft docking, adjustment of satellite attitude or orbital position, etc. In this paper, an ablative laser propulsion tractor beam is demonstrated based on radiation from a CO{sub 2} laser. Cooperative, layered polymer targets were used for remote impulse generation using a CO{sub 2} laser. The use of a structured ablatant enabling switching between thrust directional parity (i.e., forward or reverse) and imparting torque to a remote target. Fluence-dependent results are presented in the context of polymer ablation modeling work and with consideration of confined ablation effects.

  9. Action Learning: a new method to increase tractor rollover protective structure (ROPS) adoption.

    PubMed

    Biddle, Elyce Anne; Keane, Paul R

    2012-01-01

    Action Learning is a problem-solving process that is used in various industries to address difficult problems. This project applied Action Learning to a leading problem in agricultural safety. Tractor overturns are the leading cause of fatal injury to farmworkers. This cause of injury is preventable using rollover protective structures (ROPS), protective equipment that functions as a roll bar structure to protect the operator in the event of an overturn. For agricultural tractors manufactured after 1976 and employee operated, Occupational Safety and Health Administration (OSHA) regulation requires employers to equip them with ROPS and seat belts. By the mid-1980s, US tractor manufacturers began adding ROPS on all farm tractors over 20 horsepower sold in the United States (http://www.nasdonline.org/document/113/d001656/rollover-protection-for-farm-tractor-operators.html). However, many older tractors remain in use without ROPS, putting tractor operators at continued risk for traumatic injury and fatality. For many older tractor models ROPS are available for retrofit, but for a variety of reasons, tractor owners have not chosen to retrofit those ROPS. The National Institute for Occupational Safety and Health (NIOSH) attempted various means to ameliorate this occupational safety risk, including the manufacture of a low-cost ROPS for self-assembly. Other approaches address barriers to adoption. An Action Learning approach to increasing adoption of ROPS was followed in Virginia and New York, with mixed results. Virginia took action to increase the manufacturing and adoption of ROPS, but New York saw problems that would be insurmountable. Increased focus on team composition might be needed to establish effective Action Learning teams to address this problem. PMID:22994641

  10. ANNULUS CLOSURE TECHNOLOGY DEVELOPMENT INSPECTION/SALT DEPOSIT CLEANING MAGNETIC WALL CRAWLER

    SciTech Connect

    Minichan, R; Russell Eibling, R; James Elder, J; Kevin Kane, K; Daniel Krementz, D; Rodney Vandekamp, R; Nicholas Vrettos, N

    2008-06-01

    The Liquid Waste Technology Development organization is investigating technologies to support closure of radioactive waste tanks at the Savannah River Site (SRS). Tank closure includes removal of the wastes that have propagated to the tank annulus. Although amounts and types of residual waste materials in the annuli of SRS tanks vary, simple salt deposits are predominant on tanks with known leak sites. This task focused on developing and demonstrating a technology to inspect and spot clean salt deposits from the outer primary tank wall located in the annulus of an SRS Type I tank. The Robotics, Remote and Specialty Equipment (RRSE) and Materials Science and Technology (MS&T) Sections of the Savannah River National Laboratory (SRNL) collaborated to modify and equip a Force Institute magnetic wall crawler with the tools necessary to demonstrate the inspection and spot cleaning in a mock-up of a Type I tank annulus. A remote control camera arm and cleaning head were developed, fabricated and mounted on the crawler. The crawler was then tested and demonstrated on a salt simulant also developed in this task. The demonstration showed that the camera is capable of being deployed in all specified locations and provided the views needed for the planned inspection. It also showed that the salt simulant readily dissolves with water. The crawler features two different techniques for delivering water to dissolve the salt deposits. Both water spay nozzles were able to dissolve the simulated salt, one is more controllable and the other delivers a larger water volume. The cleaning head also includes a rotary brush to mechanically remove the simulated salt nodules in the event insoluble material is encountered. The rotary brush proved to be effective in removing the salt nodules, although some fine tuning may be required to achieve the best results. This report describes the design process for developing technology to add features to a commercial wall crawler and the results of the

  11. [The differential diagnosis of the types of trauma caused by wheeled tractors].

    PubMed

    Zaval'niuk, A Kh

    1993-01-01

    Examinations of 23 corpses and study of 282 expert conclusions concerning the deaths of subjects aged 6 to 78 dead because of wheeled tractor injuries under agricultural conditions helped detect the specific characteristic signs of tractor injury types. Mathematical method of analysis of the characteristic features' quantitative parameters permitted the author to find statistically reliable criteria for differential diagnosis of the types of injuries inflicted by wheeled tractors. The possibility of correct conclusions of an expert using this method is at least 95%. PMID:7940629

  12. Fatalities associated with improper hitching to farm tractors--New York, 1991-1995.

    PubMed

    1996-04-19

    Approximately half of all injury-related fatalities in the agricultural industry are associated with farm tractors (1). Since April 1991, the New York State Department of Health's Occupational Health Nurses in Agricultural Communities (OHNAC) program has investigated 27 incidents of sudden rear rollover of farm tractors (i.e., incidents in which the tractor flips backward, rotating around its rear axle); these incidents resulted in 15 fatalities. This report describes four of these incidents, summarizes the characteristics of the 16 incidents that involved improper hitching, and outlines strategies for reducing the risk for their occurrence. PMID:8602129

  13. Attitude dynamics of the Tether Elevator/Crawler System for micro-gravity applications

    NASA Technical Reports Server (NTRS)

    Vetrella, S.; Moccia, A.; Lorenzini, E. C.; Cosmo, M.

    1989-01-01

    The Tether Elevator/Crawler System (TECS) consists of two end platforms tethered to opposite sides of the Space Station. A variable gravity laboratory is located on board an elevator which can crawl along the upper tether. This paper analyzes the elevator's attitude dynamics in order to evaluate its effect on microgravity applications. To this end, a simulation model is described and numerical results are given for a steady state case. It is shown that the elevator attitude dynamics, without attitude control, contributes additional spectral lines to the acceleration noise.

  14. Metallurgical Design and Development of NASA Crawler/Transporter Tread Belt Shoe Castings

    NASA Technical Reports Server (NTRS)

    Parker, Donald S.

    2006-01-01

    The NASA Crawler/Transporters (CT-1 and CT-2) used to transport the Space Shuffles are one of the largest tracked vehicles in existence today. Two of these machines have been used to move space flight vehicles at Kennedy Space Center since the Apollo missions of the 1960's and relatively few modifications have been made to keep them operational. In September of 2003 during normal Crawler/Transporter operations cracks were observed along the roller pad surfaces of several tread belt shoes. Further examination showed 20 cracked shoes on CT-1 and 40 cracked shoes on CT-2 and a formal failure analysis investigation was undertaken while the cracked shoes were replaced. Six shoes were cross-sectioned with the fracture surfaces exposed and it was determined that the cracks were due to fatigue that initiated on the internal casting web channels at pre-existing casting defects and propagated through thickness both transgranularly and intergranularly between internal shrinkage cavities, porosity, and along austenitic and ferritic grain boundaries. The original shoes were cast during the 1960's using a modified 861330 steel with slightly higher levels of chromium, nickel and molybdenum followed by heat treatment to achieve a minimum tensile strength of 11 Oksi. Subsequent metallurgical analysis of the tread belt shoes after multiple failures showed excessive internal defects, alloy segregation, a nonuniform ferritic/ bainitic/martensitic microstructure, and low average tensile properties indicative of poor casting and poor heat-treatment. As a result, NASA funded an initiative to replace all of the tread belt shoes on both crawler/transporters along with a redesign of the alloy, manufacturing, and heat-treatment to create a homogeneous cast structure with uniform mechanical and metallurgical properties. ME Global, a wholly owned subsidiary of ME Elecmetal based in Minneapolis, MN was selected as manufacturing and design partner to develop the new shoes and this paper

  15. The BCube Crawler: Web Scale Data and Service Discovery for EarthCube.

    NASA Astrophysics Data System (ADS)

    Lopez, L. A.; Khalsa, S. J. S.; Duerr, R.; Tayachow, A.; Mingo, E.

    2014-12-01

    Web-crawling, a core component of the NSF-funded BCube project, is researching and applying the use of big data technologies to find and characterize different types of web services, catalog interfaces, and data feeds such as the ESIP OpenSearch, OGC W*S, THREDDS, and OAI-PMH that describe or provide access to scientific datasets. Given the scale of the Internet, which challenges even large search providers such as Google, the BCube plan for discovering these web accessible services is to subdivide the problem into three smaller, more tractable issues. The first, to be able to discover likely sites where relevant data and data services might be found, the second, to be able to deeply crawl the sites discovered to find any data and services which might be present. Lastly, to leverage the use of semantic technologies to characterize the services and data found, and to filter out everything but those relevant to the geosciences. To address the first two challenges BCube uses an adapted version of Apache Nutch (which originated Hadoop), a web scale crawler, and Amazon's ElasticMapReduce service for flexibility and cost effectiveness. For characterization of the services found, BCube is examining existing web service ontologies for their applicability to our needs and will re-use and/or extend these in order to query for services with specific well-defined characteristics in scientific datasets such as the use of geospatial namespaces. The original proposal for the crawler won a grant from Amazon's academic program, which allowed us to become operational; we successfully tested the Bcube Crawler at web scale obtaining a significant corpus, sizeable enough to enable work on characterization of the services and data found. There is still plenty of work to be done, doing "smart crawls" by managing the frontier, developing and enhancing our scoring algorithms and fully implementing the semantic characterization technologies. We describe the current status of the project

  16. Soil compaction and structural morphology under tractor wheelings

    NASA Astrophysics Data System (ADS)

    Shanahan, Peter; Quinton, John; Binley, Andrew; Silgram, Martyn

    2010-05-01

    Compaction of cultivated soils is a major problem for agriculture in terms of yield decline and sustainable soil resource management. Tramline wheelings exacerbate runoff and increase erosion from arable land. The UK Department for Environment, Food and Rural Affairs (Defra) LINK Project - a joint venture between agri-business, land managers and research groups - is currently evaluating a number of methods for alleviating compaction in tractor wheelings across a range of soil types in England. Using innovative applications of agri-geophysics (e.g. ground penetrating radar, electrical resistivity, acoustics and x-ray tomography), this current project aims to determine relationships between properties derived from geophysical methods (e.g. soil moisture, porosity), soil compaction and structural morphology. Such relationships are important for a clearer understanding of hydrological and biogeochemical processes in compacted soils, to address land management practices and develop cost-effective mitigation measures. Our poster will present some early results of this study.

  17. The Tractor: Probabilistic astronomical source detection and measurement

    NASA Astrophysics Data System (ADS)

    Lang, Dustin; Hogg, David W.; Mykytyn, David

    2016-04-01

    The Tractor optimizes or samples from models of astronomical objects. The approach is generative: given astronomical sources and a description of the image properties, the code produces pixel-space estimates or predictions of what will be observed in the images. This estimate can be used to produce a likelihood for the observed data given the model: assuming the model space actually includes the truth (it doesn’t, in detail), then if we had the optimal model parameters, the predicted image would differ from the actually observed image only by noise. Given a noise model of the instrument and assuming pixelwise independent noise, the log-likelihood is the negative chi-squared difference: (image - model) / noise.

  18. An investigation of drag reduction for tractor trailer vehicles

    NASA Technical Reports Server (NTRS)

    Muirhead, V. U.

    1978-01-01

    Force and moment data were obtained from a one-twenty-fifth scale wind tunnel model of a cab-over-engine tractor trailer combination. The tests define the aerodynamic characteristics of the baseline (unmodified) vehicle and several modified configurations. The primary modifications consist of: (1) greatly increased forebody corner radii, (2) a smooth fairing over the cab-to-trailer gap, (3) a smoothed underbody, and (4) rear streamlining (boattailing)of the trailer. Tests were conducted for yaw angles from 0 deg to 30 deg. The reduction in drag, relative to the baseline, obtained by combining the modifications are compared for the zero yaw condition with full scale coast down drag results for similar configurations. The drag reductions obtained from the model and full scale tests are in good agreement.

  19. Quantum coherent tractor beam effect for atoms trapped near a nanowaveguide

    PubMed Central

    Sadgrove, Mark; Wimberger, Sandro; Nic Chormaic, Síle

    2016-01-01

    We propose several schemes to realize a tractor beam effect for ultracold atoms in the vicinity of a few-mode nanowaveguide. Atoms trapped near the waveguide are transported in a direction opposite to the guided mode propagation direction. We analyse three specific examples for ultracold 23Na atoms trapped near a specific nanowaveguide (i.e. an optical nanofibre): (i) a conveyor belt-type tractor beam effect, (ii) an accelerator tractor beam effect, and (iii) a quantum coherent tractor beam effect, all of which can effectively pull atoms along the nanofibre toward the light source. This technique provides a new tool for controlling the motion of particles near nanowaveguides with potential applications in the study of particle transport and binding as well as atom interferometry. PMID:27440516

  20. Summary of NREL's Recent Class 8 Tractor Trailer Platooning Testing (Presentation)

    SciTech Connect

    Lammert, M.; Kelly, K.; Walkowicz, K.

    2014-08-01

    This presentation summarizes NREL's recent class 8 tractor trailer platooning testing, including analysis of SAE J1321 Type II fuel consumption testing, fuel consumption improvement, fuel economy and platooning position accuracy.

  1. Quantum coherent tractor beam effect for atoms trapped near a nanowaveguide.

    PubMed

    Sadgrove, Mark; Wimberger, Sandro; Nic Chormaic, Síle

    2016-01-01

    We propose several schemes to realize a tractor beam effect for ultracold atoms in the vicinity of a few-mode nanowaveguide. Atoms trapped near the waveguide are transported in a direction opposite to the guided mode propagation direction. We analyse three specific examples for ultracold (23)Na atoms trapped near a specific nanowaveguide (i.e. an optical nanofibre): (i) a conveyor belt-type tractor beam effect, (ii) an accelerator tractor beam effect, and (iii) a quantum coherent tractor beam effect, all of which can effectively pull atoms along the nanofibre toward the light source. This technique provides a new tool for controlling the motion of particles near nanowaveguides with potential applications in the study of particle transport and binding as well as atom interferometry. PMID:27440516

  2. Quantum coherent tractor beam effect for atoms trapped near a nanowaveguide

    NASA Astrophysics Data System (ADS)

    Sadgrove, Mark; Wimberger, Sandro; Nic Chormaic, Síle

    2016-07-01

    We propose several schemes to realize a tractor beam effect for ultracold atoms in the vicinity of a few-mode nanowaveguide. Atoms trapped near the waveguide are transported in a direction opposite to the guided mode propagation direction. We analyse three specific examples for ultracold 23Na atoms trapped near a specific nanowaveguide (i.e. an optical nanofibre): (i) a conveyor belt-type tractor beam effect, (ii) an accelerator tractor beam effect, and (iii) a quantum coherent tractor beam effect, all of which can effectively pull atoms along the nanofibre toward the light source. This technique provides a new tool for controlling the motion of particles near nanowaveguides with potential applications in the study of particle transport and binding as well as atom interferometry.

  3. Effect of Road Adhesion Coefficient on Tractor-Semitrailer Cornering Braking Stability

    NASA Astrophysics Data System (ADS)

    Wang, Wei; Li, Chen; Tang, Geteng; Wang, Cheng

    A dynamic model of tractor-semitrailer cornering braking was established in this paper, and the accuracy of the model was verified by real vehicle test. By model simulation of the cornering braking process, different road adhesion coefficient such as 0.15, 0.3, 0.45, 0.6, 0.75 was chosen to analyzed the changing curve of braking distance, articulation angle, yaw rate and lateral acceleration when initial speed of tractor-semitrailer was 30km h. The result showed that the peak values of articulation angle, yaw rate and lateral acceleration gotten by simulation were the largest. On the road of road adhesion coefficient 0.15, distance of tractor-semitrailer cornering braking was the longest. On the road of road adhesion coefficient 0.75, distance of tractor-semitrailer cornering braking was the shortest and the peak values of articulation angle, yaw rate and lateral acceleration were small relatively.

  4. Design and Implementation of a GPS Guidance System for Agricultural Tractors Using Augmented Reality Technology

    PubMed Central

    Santana-Fernández, Javier; Gómez-Gil, Jaime; del-Pozo-San-Cirilo, Laura

    2010-01-01

    Current commercial tractor guidance systems present to the driver information to perform agricultural tasks in the best way. This information generally includes a treated zones map referenced to the tractor’s position. Unlike actual guidance systems where the tractor driver must mentally associate treated zone maps and the plot layout, this paper presents a guidance system that using Augmented Reality (AR) technology, allows the tractor driver to see the real plot though eye monitor glasses with the treated zones in a different color. The paper includes a description of the system hardware and software, a real test done with image captures seen by the tractor driver, and a discussion predicting that the historical evolution of guidance systems could involve the use of AR technology in the agricultural guidance and monitoring systems. PMID:22163479

  5. Exposure to audible and infrasonic noise by modern agricultural tractors operators.

    PubMed

    Bilski, Bartosz

    2013-03-01

    The wheeled agricultural tractor is one of the most prominent sources of noise in agriculture. This paper presents the assessment of the operator's exposure to audible and infrasonic noise in 32 selected modern wheeled agricultural tractors designed and produced by world-renowned companies in normal working conditions. The tractors have been in use for no longer than 4 years, with rated power of 51 kW to up to 228 kW (as per 97/68 EC). Audible and infrasonic noise level measurements and occupational exposure analysis to noise were performed according to ISO 9612:2009 (strategy 1 - task-based measurements). The measurements were made in different typical work conditions inside and outside of tractors cabs. The results indicated that exposure levels to noise perceived by the operators (L(ex,Te) between 62,3 and 84,7 dB-A) and can make a small risk of potential adversely effects on hearing during tasks performed inside the closed cab. It should be remarked that uncertainty interval is wider and in in some conditions can occur transgression of audible noise occupational exposure limits. The measured audible noise levels can potentially develop the non-auditory effects. Analysed tractors emit considerable infrasonic noise levels that tend to exceed the occupational exposure limits (both inside and outside the driver's cab). The levels of infrasound: 83,8-111,4 dB-G. All tractors introduced for sale should be subjected to tests in terms of infrasonic noise levels. The applicable standards for low frequency noise and its measurement methods for vehicles, including agricultural tractors, should be scientifically revised. In the last years there has been a noticeable technical progress in reduction of audible noise exposure at the tractors operators workplaces with simultaneously lack of important works for limitation of exposure to infrasound. Author discuss possible health and ergonomic consequencies of such exposure. PMID:22877701

  6. [Risk of noise-induced hearing loss in farm tractor operators].

    PubMed

    Solecki, L

    2001-01-01

    Studies of noise at work site of tractor operators showed that this parameter exceeds allowable values. In order to evaluate the risk of hearing loss in this occupational group, noise-induced permanent threshold shift (NIPTS) values were determined. This parameter is a function of the audiometric frequency, duration of occupational exposure and noise exposure level (LEX,8 h). The procedure recommended by ISO-1999/1990 was used for calculations. The study covered two groups of operators: operators of ZM "Ursus" medium-power tractors (noise exposure level: LEX,8 h = 96.6 dB) and operators of high-power tractors of the same manufacture (LEX,8 h = 89.6 dB) The risk of hearing impairment was determined for the group of men aged 50 years, occupationally exposed to noise for a period of 30 years. The calculation was based on the mean value of expected hearing loss for three selected audiometric frequencies: 1000; 2000; and 4000 Hz. The study showed that the average (median; N0.50) expected hearing loss, excluding that associated with age, after 30 years of employment was 15 dB for operators of medium-power farm tractors, and 6 dB for operators of high-power tractors. The risk of hearing impairment due to occupational exposure to noise (exceeding the maximum allowable hearing loss of 27 dB; according to ISO-1999/1990) that may cause an acoustic trauma was 37.9% for medium-power tractors and 13.0% for high-power tractors. The results of the study show that noise at workplaces of farm tractor operators creates a high risk of hearing impairment. PMID:11761672

  7. Investigation of Tractor Base Bleeding for Heavy Vehicle Aerodynamic Drag Reduction

    SciTech Connect

    Ortega, J; Salari, K; Storms, B

    2007-10-25

    One of the main contributors to the aerodynamic drag of a heavy vehicle is tractor-trailer gap drag, which arises when the vehicle operates within a crosswind. Under this operating condition, freestream flow is entrained into the tractor-trailer gap, imparting a momentum exchange to the vehicle and subsequently increasing the aerodynamic drag. While a number of add-on devices, including side extenders, splitter plates, vortex stabilizers, and gap sealers, have been previously tested to alleviate this source of drag, side extenders remain the primary add-on device of choice for reducing tractor-trailer gap drag. However, side extenders are not without maintenance and operational issues. When a heavy vehicle pivots sharply with respect to the trailer, as can occur during loading or unloading operations, the side extenders can become crushed against the trailer. Consequently, fleet operators are forced to incur additional costs to cover the repair or replacement of the damaged side extenders. This issue can be overcome by either shortening the side extenders or by devising an alternative drag reduction concept that can perform just as effectively as side extenders. To explore such a concept, we investigate tractor base bleeding as a means of reducing gap drag. Wind tunnel measurements are made on a 1:20 scale heavy vehicle model at a vehicle width-based Reynolds number of 420,000. The tractor bleeding flow, which is delivered through a porous material embedded within the tractor base, is introduced into the tractor-trailer gap at bleeding coefficients ranging from 0.0-0.018. To determine the performance of tractor base bleeding under more realistic operating conditions, computational fluid dynamics simulations are performed on a full-scale heavy vehicle within a crosswind for bleeding coefficients ranging from 0.0-0.13.

  8. A user-oriented web crawler for selectively acquiring online content in e-health research

    PubMed Central

    Xu, Songhua; Yoon, Hong-Jun; Tourassi, Georgia

    2014-01-01

    Motivation: Life stories of diseased and healthy individuals are abundantly available on the Internet. Collecting and mining such online content can offer many valuable insights into patients’ physical and emotional states throughout the pre-diagnosis, diagnosis, treatment and post-treatment stages of the disease compared with those of healthy subjects. However, such content is widely dispersed across the web. Using traditional query-based search engines to manually collect relevant materials is rather labor intensive and often incomplete due to resource constraints in terms of human query composition and result parsing efforts. The alternative option, blindly crawling the whole web, has proven inefficient and unaffordable for e-health researchers. Results: We propose a user-oriented web crawler that adaptively acquires user-desired content on the Internet to meet the specific online data source acquisition needs of e-health researchers. Experimental results on two cancer-related case studies show that the new crawler can substantially accelerate the acquisition of highly relevant online content compared with the existing state-of-the-art adaptive web crawling technology. For the breast cancer case study using the full training set, the new method achieves a cumulative precision between 74.7 and 79.4% after 5 h of execution till the end of the 20-h long crawling session as compared with the cumulative precision between 32.8 and 37.0% using the peer method for the same time period. For the lung cancer case study using the full training set, the new method achieves a cumulative precision between 56.7 and 61.2% after 5 h of execution till the end of the 20-h long crawling session as compared with the cumulative precision between 29.3 and 32.4% using the peer method. Using the reduced training set in the breast cancer case study, the cumulative precision of our method is between 44.6 and 54.9%, whereas the cumulative precision of the peer method is between 24.3 and

  9. The Social Marketing of Safety Behaviors: A Quasi–Randomized Controlled Trial of Tractor Retrofitting Incentives

    PubMed Central

    Jenkins, Paul L.; Emmelin, Maria; Stenlund, Hans; Weinehall, Lars; Earle-Richardson, Giulia B.; May, John J.

    2011-01-01

    Objectives. We assessed the effect of social marketing incentives on dispositions toward retrofitting and retrofitting behavior among farmers whose tractors lacked rollover protective structures. Methods. From 2006 to 2007, we conducted a quasi–randomized controlled trial with 391 farm owners in New York and Pennsylvania surveyed before and after exposure to 1 of 3 tractor retrofitting incentive combinations. These combinations were offered in 3 trial regions; region 1 received rebates; region 2 received rebates, messages, and promotion and was considered the social marketing region; and region 3 received messages and promotion. A fourth region served as a control. Results. The social marketing region generated the greatest increases in readiness to retrofit, intentions to retrofit, and message recall. In addition, postintervention stage of change, intentions, attitudes, subjective norms, and perceived behavioral control levels were higher among farmers who had retrofitted tractors. Conclusions. Our results showed that a social marketing approach (financial incentives, tailored messages, and promotion) had the greatest influence on message recall, readiness to retrofit tractors, and intentions to retrofit tractors and that behavioral measures were fairly good predictors of tractor retrofitting behaviors. PMID:21330581

  10. Anthropometric criteria for the design of tractor cabs and protection frames.

    PubMed

    Hsiao, H; Whitestone, J; Bradtmiller, B; Whisler, R; Zwiener, J; Lafferty, C; Kau, T-Y; Gross, M

    2005-03-15

    Improved human-tractor interface designs, such as well-accommodated operator enclosures (i.e. cabs and protection frames) can enhance operator productivity, comfort and safety. This study investigated farm-worker anthropometry and determined the critical anthropometric measures and 3-D feature envelopes of body landmarks for the design of tractor operator enclosures. One hundred agriculture workers participated in the study. Their body size and shape information was registered, using a 3-D full-body laser scanner. Knee height (sitting) and another eight parameters were found to affect the cab-enclosure accommodation rating and multiple anthropometric dimensions interactively affected the steering wheel and gear-handle impediment. A principal component analysis has identified 15 representative human body models for digitally assessing tractor-cab accommodation. A set of centroid coordinates of 34 body landmarks and the 95% confidence semi-axis-length for each landmark location were developed to guide tractor designers in their placement of tractor control components in order to best accommodate the user population. Finally, the vertical clearance (90 cm) for agriculture tractor enclosure in the current SAE International J2194 standard appeared to be too short as compared to the 99th percentile sitting height of male farm workers in this study (100.6 cm) and in the 1994 National Health and Nutrition Examination Survey III database (99.9 cm) and of the male civilian population in the 2002 Civilian American and European Surface Anthropometric Resource database (100.4 cm). PMID:15804844

  11. A summary of state laws regulating youth operating farm tractors on highways.

    PubMed

    Doty, B C; Marlenga, B

    2006-02-01

    Driving farm tractors on highways is hazardous for youth due to the large speed differential between motor vehicles and agricultural vehicles, as well as recent increases in traffic volume on many rural roads. In 1994, the state of Wisconsin enacted legislation requiring youth who operate farm tractors on highways to complete a tractor and machinery certification course. We were interested in finding out whether other states have similar requirements. The purpose of this project was to collect and summarize state laws regulating youth who operate farm tractors on highways in the U.S. A systematic method was used that included an initial Lexis-Nexis database search followed by internet searches in combination with follow-up email and telephone communications when missing or unclear results were obtained. The findings show that 14 states have legislation addressing youth who operate farm tractors on highways. The content of these statutes varies, but includes driver's license or educational requirements, as well as regulations concerning the ages, locations, and/or times of day when youth may drive farm machinery on highways. This compilation of state laws will be useful information for agricultural safety professionals in designing effective outreach programs. A synthesis of the findings may also lead to the development of model legislation or inform future research efforts aimed at preventing youth farm tractor crashes on highways. PMID:16536173

  12. Field Tests of a Tractor Rollover Detection and Emergency Notification System.

    PubMed

    Liu, B; Koc, A B

    2015-04-01

    The objective of this research was to assess the feasibility of a rollover detection and emergency notification system for farm tractors using field tests. The emergency notification system was developed based on a tractor stability model and implemented on a mobile electronic device with the iOS operating system. A complementary filter was implemented to combine the data from the accelerometer and gyroscope sensors to improve their accuracies in calculating the roll and pitch angles and the roll and pitch rates. The system estimates a stability index value during tractor operation, displays feedback messages when the stability index is lower than a preset threshold value, and transmits emergency notification messages when an overturn happens. Ten tractor rollover tests were conducted on a field track. The developed system successfully monitored the stability of the tractor during all of the tests. The iOS application was able to detect rollover accidents and transmit emergency notifications in the form of a phone call and email when an accident was detected. The system can be a useful tool for training and education in safe tractor operation. The system also has potential for stability monitoring and emergency notification of other on-road and off-road motorized vehicles. PMID:26204787

  13. Implementing a National Tractor Safety Program: Using "Whole System in a Room" to Mobilize Partners and Implement Solutions.

    PubMed

    Tinc, Pamela J; Ayers, Paul; May, John J; Purschwitz, Mark A; Park, Samantha; Bayes, Barbara; Sorensen, Julie

    2016-01-01

    Fatalities due to tractor overturns have long plagued the U.S. farm community. Constituting 20% of agricultural fatalities, tractor overturns contribute significantly to high rates of fatal injuries. In the past, many efforts have been directed toward reducing tractor overturns, with one successful US-based program offering rebates to farmers who retrofit their tractors with rollover protective structures (ROPS). In an effort to expand the program, the National Tractor Safety Coalition was formed. This coalition hosted a "Whole System in the Room" workshop to bring 50 stakeholders together. During this workshop, participants worked together to identify a common vision for the future of tractor safety and ROPS programs and commit to action. At the close of the workshop, coalition members set out to begin work on 100 short- and long-term commitments to begin implementing a National ROPS Rebate Program. PMID:26788905

  14. Frequency and severity of injuries to operators during overturns of farm tractors.

    PubMed

    Cole, H P; Myers, M L; Westneat, S C

    2006-05-01

    Previous estimates of operator death from farm tractor overturn events range from 0.03 to 0.68. This study provided population-based estimates of the denominator of total farm tractor overturns and the frequency of six classes of overturn injury outcomes for tractors with and without rollover protective structures (ROPS). A 40-item telephone survey collected information from a random sample of 6,063 (8.0%) Kentucky farms about each farm's most recent overturn. A total of 551 (9.1%) farms reported overturns, and 5,512 (90.1%) reported no overturns. Injury outcomes for 443 overturns of non-ROPS tractors and 89 ROPS tractors were distributed as follows: no or minor injury (non-ROPS: 70.43%; ROPS: 82.02%), outpatient treatment (non-ROPS: 21.90%; ROPS: 9.00%), hospital admission (non-ROPS: 15.35%; ROPS: 3.37%), temporary disability (non-ROPS: 13.54%; ROPS: 14.61%), permanent disability (non-ROPS: 3.16%; ROPS: 0.00%), and death (non-ROPS: 5.42%; ROPS: 1.12%). (Percents total to more than 100 because some operators treated as outpatients were subsequently hospitalized, disabled, or died.) The observed 0.054 probability of death from overturn of non-ROPS tractors in this sample was corrected for the proportion of farms that went out of business prior to the survey and thus were excluded from the sampling frame. The adjusted 0.08 probability of death from overturn of a non-ROPS tractor is five times smaller than the NIOSH estimate of 0.40. The discrepancy lies in the much larger denominator of all non-fatal and fatal overturns than assumed previously. PMID:16724789

  15. Optimization of motion control laws for tether crawler or elevator systems

    NASA Technical Reports Server (NTRS)

    Swenson, Frank R.; Von Tiesenhausen, Georg

    1988-01-01

    Based on the proposal of a motion control law by Lorenzini (1987), a method is developed for optimizing motion control laws for tether crawler or elevator systems in terms of the performance measures of travel time, the smoothness of acceleration and deceleration, and the maximum values of velocity and acceleration. The Lorenzini motion control law, based on powers of the hyperbolic tangent function, is modified by the addition of a constant-velocity section, and this modified function is then optimized by parameter selections to minimize the peak acceleration value for a selected travel time or to minimize travel time for the selected peak values of velocity and acceleration. It is shown that the addition of a constant-velocity segment permits further optimization of the motion control law performance.

  16. Using data crawlers and semantic Web to build financial XBRL data generators: the SONAR extension approach.

    PubMed

    Rodríguez-García, Miguel Ángel; Rodríguez-González, Alejandro; Colomo-Palacios, Ricardo; Valencia-García, Rafael; Gómez-Berbís, Juan Miguel; García-Sánchez, Francisco

    2014-01-01

    Precise, reliable and real-time financial information is critical for added-value financial services after the economic turmoil from which markets are still struggling to recover. Since the Web has become the most significant data source, intelligent crawlers based on Semantic Technologies have become trailblazers in the search of knowledge combining natural language processing and ontology engineering techniques. In this paper, we present the SONAR extension approach, which will leverage the potential of knowledge representation by extracting, managing, and turning scarce and disperse financial information into well-classified, structured, and widely used XBRL format-oriented knowledge, strongly supported by a proof-of-concept implementation and a thorough evaluation of the benefits of the approach. PMID:24587726

  17. Using Data Crawlers and Semantic Web to Build Financial XBRL Data Generators: The SONAR Extension Approach

    PubMed Central

    Rodríguez-García, Miguel Ángel; Rodríguez-González, Alejandro; Valencia-García, Rafael; Gómez-Berbís, Juan Miguel

    2014-01-01

    Precise, reliable and real-time financial information is critical for added-value financial services after the economic turmoil from which markets are still struggling to recover. Since the Web has become the most significant data source, intelligent crawlers based on Semantic Technologies have become trailblazers in the search of knowledge combining natural language processing and ontology engineering techniques. In this paper, we present the SONAR extension approach, which will leverage the potential of knowledge representation by extracting, managing, and turning scarce and disperse financial information into well-classified, structured, and widely used XBRL format-oriented knowledge, strongly supported by a proof-of-concept implementation and a thorough evaluation of the benefits of the approach. PMID:24587726

  18. Automated field testing of a track-type tractor

    NASA Astrophysics Data System (ADS)

    Taylor, Michael A.; Lay, Keith; Struble, Joshua; Allen, William; Subrt, Michael

    2003-09-01

    During the design process, earthmoving manufacturers routinely subject machines to rigorous, long-term tests to ensure quality. Automating portions of the testing process can potentially reduce the cost and time to complete these tests. We present a system that guides a 175 horsepower track-type tractor (Caterpillar Model D6R XL) along a prescribed route, allowing simple tasks to be completed by the automated machine while more complex tasks, such as site clean up, are handled by an operator. Additionally, the machine can be operated manually or via remote control and observed over the internet using a remote supervisor program. We envision that safety would be handled using work procedures, multiple over-ride methods and a GPS fence. The current system can follow turns within a half meter and straight sections within a quarter meter. The controller hardware and software are integrated with existing on-board electronic modules and allow for portability. The current system successfully handles the challenges of a clutch-brake drive train and has the potential to improve control over test variables, lower testing costs and enable testing at higher speeds allowing for higher impact tests than a human operator can tolerate.

  19. Space Shuttle Crawler Transporter Vibration Analysis in Support of Rollout Fatigue Load Spectra Verification Program

    NASA Technical Reports Server (NTRS)

    Margasahayam, Ravi N.; Meyer, Karl A.; Nerolich, Shaun M.; Burton, Roy C.; Gosselin, Armand M.

    2004-01-01

    The Crawler Transporter (CT), designed and built for the Apollo Program in the 1960's and surpassing its initial operational life, has become an integral part of the Space Shuttle Program (SSP). The CT transports the Space Shuttle Vehicle (SSV) stack, atop the Mobile Launch Platform (MLP), from the Vehicle Assembly Building (VAB) to the launch pad. This support structure provides hydraulic jacking, leveling and load equalization for the 12 million pound stack on its 3.5-5.0 mile rollout to the launch pad. Major elements of the SSV, consisting of the orbiter, solid rocket boosters (SRB) and external tank (ET) have required fatigue analyses as part of the mission life certification. Compared to rollout vibration, the SSV sees relatively high vibration loads during launch, ascent, descent and landing phases of the mission. Although preliminary measured SRB vibration levels during rollout were of low amplitude and frequency, the duration of the rollout phase is typically high, from 5-6 hours. As part of an expanded mission life assessment, additional certification effort was initiated to define fatigue load spectra for rollout. This study addresses the CT vibration analyses in support of the rollout fatigue study. Structural models developed for modal and vibration analyses were used to identify unique CT, CT/MLP and CT/MLP/SRB vibration characteristics for comparison to instrumented rollout tests. Whereas the main structural and vibration characteristics of the SSV are well defined, minimum analytical and vibration test data on the Crawler Transporter were available. Unique vibration characteristics of the CT are attributable to the drive mechanism, hydraulic jacking system, structural framing and the CT-to-MLP support pad restraints. Initial tests performed on the CT/MLP/SRB configuration showed reasonable correlation with predicted mode shapes and frequencies.

  20. Nematoelastic crawlers

    NASA Astrophysics Data System (ADS)

    Zakharov, A. P.; Pismen, L. M.

    2016-02-01

    A propagating "beam" triggering a local phase transition in a nematic elastomer sets it into a crawling motion, which may morph due to buckling. We consider the motion of the various configurations of slender rods and thin stripes with both uniform and splayed nematic order in cross-section and detect the dependence of the gait and speed on flexural rigidity and substrate friction.

  1. A Kalman Filter Implementation for Precision Improvement in Low-Cost GPS Positioning of Tractors

    PubMed Central

    Gomez-Gil, Jaime; Ruiz-Gonzalez, Ruben; Alonso-Garcia, Sergio; Gomez-Gil, Francisco Javier

    2013-01-01

    Low-cost GPS receivers provide geodetic positioning information using the NMEA protocol, usually with eight digits for latitude and nine digits for longitude. When these geodetic coordinates are converted into Cartesian coordinates, the positions fit in a quantization grid of some decimeters in size, the dimensions of which vary depending on the point of the terrestrial surface. The aim of this study is to reduce the quantization errors of some low-cost GPS receivers by using a Kalman filter. Kinematic tractor model equations were employed to particularize the filter, which was tuned by applying Monte Carlo techniques to eighteen straight trajectories, to select the covariance matrices that produced the lowest Root Mean Square Error in these trajectories. Filter performance was tested by using straight tractor paths, which were either simulated or real trajectories acquired by a GPS receiver. The results show that the filter can reduce the quantization error in distance by around 43%. Moreover, it reduces the standard deviation of the heading by 75%. Data suggest that the proposed filter can satisfactorily preprocess the low-cost GPS receiver data when used in an assistance guidance GPS system for tractors. It could also be useful to smooth tractor GPS trajectories that are sharpened when the tractor moves over rough terrain. PMID:24217355

  2. A Kalman filter implementation for precision improvement in low-cost GPS positioning of tractors.

    PubMed

    Gomez-Gil, Jaime; Ruiz-Gonzalez, Ruben; Alonso-Garcia, Sergio; Gomez-Gil, Francisco Javier

    2013-01-01

    Low-cost GPS receivers provide geodetic positioning information using the NMEA protocol, usually with eight digits for latitude and nine digits for longitude. When these geodetic coordinates are converted into Cartesian coordinates, the positions fit in a quantization grid of some decimeters in size, the dimensions of which vary depending on the point of the terrestrial surface. The aim of this study is to reduce the quantization errors of some low-cost GPS receivers by using a Kalman filter. Kinematic tractor model equations were employed to particularize the filter, which was tuned by applying Monte Carlo techniques to eighteen straight trajectories, to select the covariance matrices that produced the lowest Root Mean Square Error in these trajectories. Filter performance was tested by using straight tractor paths, which were either simulated or real trajectories acquired by a GPS receiver. The results show that the filter can reduce the quantization error in distance by around 43%. Moreover, it reduces the standard deviation of the heading by 75%. Data suggest that the proposed filter can satisfactorily preprocess the low-cost GPS receiver data when used in an assistance guidance GPS system for tractors. It could also be useful to smooth tractor GPS trajectories that are sharpened when the tractor moves over rough terrain. PMID:24217355

  3. 29 CFR 1928.51 - Roll-over protective structures (ROPS) for tractors used in agricultural operations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... tractors shall meet the test and performance requirements of 29 CFR 1928.52, 1928.53, or 1926.1002 as appropriate. A ROPS used on track-type tractors shall meet the test and performance requirements of 29 CFR... horizontal in and upward and rearward direction. Floor and seat deformation is acceptable provided there...

  4. 29 CFR 1928.51 - Roll-over protective structures (ROPS) for tractors used in agricultural operations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... tractors shall meet the test and performance requirements of 29 CFR 1928.52, 1928.53, or 1926.1002 as appropriate. A ROPS used on track-type tractors shall meet the test and performance requirements of 29 CFR... horizontal in and upward and rearward direction. Floor and seat deformation is acceptable provided there...

  5. 29 CFR 1928.51 - Roll-over protective structures (ROPS) for tractors used in agricultural operations.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... tractors shall meet the test and performance requirements of 29 CFR 1928.52, 1928.53, or 1926.1002 as appropriate. A ROPS used on track-type tractors shall meet the test and performance requirements of 29 CFR... horizontal in and upward and rearward direction. Floor and seat deformation is acceptable provided there...

  6. 29 CFR 1928.51 - Roll-over protective structures (ROPS) for tractors used in agricultural operations.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... tractors shall meet the test and performance requirements of 29 CFR 1928.52, 1928.53, or 1926.1002 as appropriate. A ROPS used on track-type tractors shall meet the test and performance requirements of 29 CFR... horizontal in and upward and rearward direction. Floor and seat deformation is acceptable provided there...

  7. Transmission and pto system for tractors and utility cycles

    SciTech Connect

    Rundle, K.P.

    1987-04-21

    A tractor power transmission is described comprised of: a speed transmission housing, a first transmission shaft journalled in the housing, a hollow second transmission shaft journalled in the housing generally below and parallel to the first transmission shaft. A PTO drive shaft journalled in the housing and passing axially within the second transmission shaft and protruding forward and rearward from the second transmission shaft. A third transmission shaft is journalled in the housing parallel to the second transmission shaft. A final drive differential journalled in the housing perpendicular to the third transmission shaft, a coaxial rearward extension shaft to the PTO drive shaft journalled in the housing to provide a rear PTO drive. Gear means to drivingly connect the second and the third transmission shafts, gear means to drivingly connect the third transmission shaft and the final drive differential. A first set of intermeshing gears on the first and the second transmission shafts to drivingly connect the first and the second transmission shafts, a second set of intermeshing gears on the first transmission shaft and the PTO drive shaft PTO clutch means shiftable to drivingly connect the first transmission shaft. And PTO drive shaft through the second set of intermeshing gears at a first speed ratio when the PTO clutch means are in a first actuated state, the PTO clutch means is shiftable to drivingly connect the first transmission shaft and the PTO drive shaft through the first set of intermeshing gears at a second speed ratio. When the PTO clutch means are in a second actuated state and while the first set of intermeshing gears continues to provide a line of drive from the first transmission shaft to the second transmission shaft.

  8. Evaluation of Corrosion Failure in Tractor-Trailer Brake System

    SciTech Connect

    Wilson, DF

    2002-10-22

    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.

  9. Pipe Crawler{reg_sign} internal piping characterization system - deactivation and decommissioning focus area. Innovative Technology Summary Report

    SciTech Connect

    1998-02-01

    Pipe Crawler{reg_sign} is a pipe surveying system for performing radiological characterization and/or free release surveys of piping systems. The technology employs a family of manually advanced, wheeled platforms, or crawlers, fitted with one or more arrays of thin Geiger Mueller (GM) detectors operated from an external power supply and data processing unit. Survey readings are taken in a step-wise fashion. A video camera and tape recording system are used for video surveys of pipe interiors prior to and during radiological surveys. Pipe Crawler{reg_sign} has potential advantages over the baseline and other technologies in areas of cost, durability, waste minimization, and intrusiveness. Advantages include potentially reduced cost, potential reuse of the pipe system, reduced waste volume, and the ability to manage pipes in place with minimal disturbance to facility operations. Advantages over competing technologies include potentially reduced costs and the ability to perform beta-gamma surveys that are capable of passing regulatory scrutiny for free release of piping systems.

  10. Towing Asteroids with Gravity Tractors Enhanced by Tethers and Solar Sails

    NASA Technical Reports Server (NTRS)

    Shen, Haijun; Roithmayr, Carlos M.

    2015-01-01

    Material collected from an asteroid's surface can be used to increase gravitational attraction between the asteroid and a Gravity Tractor (GT); the spacecraft therefore operates more effectively and is referred to as an Enhanced Gravity Tractor (EGT). The use of tethers and solar sails to further improve effectiveness and simplify operations is investigated. By employing a tether, the asteroidal material can be placed close to the asteroid while the spacecraft is stationed farther away, resulting in a better safety margin and improved thruster efficiency. A solar sail on a spacecraft can naturally provide radial offset and inter-spacecraft separation required for multiple EGTs.

  11. Impact of tracked and rubber-tired tractors on a forest soil

    SciTech Connect

    Burger, J.A.; Perumpral, J.V.; Kreh, R.E.; Jorbet, J.L.; Minaei, S.

    1985-03-01

    Despite a three-fold difference in mean ground pressure, changes in soil density and porosity caused by an unloaded, rubber-tired log skidder did not exceed those caused by a crawler. The changes in soil density and porosity caused by these machines increased with soil moisture content. Soil density and porosity change proportionally with the square root of the number of passes over the same area. 24 references.

  12. 49 CFR 399.207 - Truck and truck-tractor access requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 5 2012-10-01 2012-10-01 false Truck and truck-tractor access requirements. 399.207 Section 399.207 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL MOTOR CARRIER SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION FEDERAL MOTOR CARRIER SAFETY REGULATIONS EMPLOYEE SAFETY AND HEALTH STANDARDS...

  13. A History of the Caterpillar Tractor Company's Use of Motion Pictures.

    ERIC Educational Resources Information Center

    Veeder, Gerry A.

    Film historians have tended to overlook the industrial film even though it has been widely used as a sales tool since early in this century. The Caterpillar Tractor Company was one of the first to adopt this medium as a means of demonstrating what its machines could do in a variety of situations. While other types of films have been made by…

  14. Tractor Mechanics: Maintaining and Servicing the Fuel System. Learning Activity Packages 20-33.

    ERIC Educational Resources Information Center

    Clemson Univ., SC. Vocational Education Media Center.

    Learning activity packages are presented for instruction in tractor mechanics. The packages deal with the duties involved in maintaining the fuel system. The following fourteen learning activity packages are included: servicing fuel and air filters, servicing fuel tanks and lines, adjusting a carburetor, servicing a carburetor, servicing the…

  15. Analysis of bifurcation and stability for a tractor semi-trailer in planar motion

    NASA Astrophysics Data System (ADS)

    Ding, Nenggen; Shi, Xiaobo; Zhang, Yipeng; Chen, Wen

    2014-12-01

    This paper is intended for bifurcation analysis of a nonlinear tractor semi-trailer vehicle model in planar motion and for investigating its stability under constant running conditions. Bifurcation analysis shows that bifurcation diagrams of a tractor semi-trailer are quite different from those of a single-unit vehicle. Some instability phenomena of the vehicle system such as jackknifing, sideslip, and spinning are explained by correlating them with the behaviour in the neighbourhood of unstable fixed points based on analysis of eigenvectors, phase trajectories, and status of lateral tyre force saturation. It is also found that yaw planar instability of a tractor semi-trailer is caused by lateral tyre force saturation of the tractor's rear axles and/or the trailer's axles. Moreover, the stability region in the state space is demarcated, and a stability index for evaluating size of the stability region in a feasible domain is proposed. Yaw stability under constant driving conditions is analysed by using the proposed stability index.

  16. The Development of Procedural Knowledge in Adults Engaged in a Tractor-Trailer Task.

    ERIC Educational Resources Information Center

    Moses, Nelson

    1994-01-01

    Studied development of procedural knowledge in 14 adults, aged 18 to 35 years, engaged in a novel task using a toy tractor-trailer rig. Results revealed three phases of development in subjects' knowledge of steering procedures and the rig's movement patterns, and their use of feedback information. Subjects also manifested different levels of…

  17. New method of space debris cleaning based on light negative force: tractor laser

    NASA Astrophysics Data System (ADS)

    Sun, Qiongge; Gao, Long; Li, Chen

    2016-01-01

    This paper presents a new way of space debris removal and protection, that is, using tractor laser, which based on light negative force, to achieve space debris cleaning and shielded. Tractor laser is traceable from the theory of optical tweezers, accompanied with non-diffraction beam. These kind of optical beams have the force named negative force pointing to optical source, this will bring the object along the trajectory of laser beam moving to the optical source. The negative force leads to the new method to convey and sampling the space micro-objects. In this paper, the application of tractor laser in the space debris collection and protection of 1cm is studied. The application of the several tractor beams in the space debris and sample collection is discussed. The proposed method can reduce the requirements of the laser to the satellite platform, and realize the collection of space debris, make the establishment of the space garbage station possible, and help to study the spatial non contact sample transmission and reduce the risk of space missions.

  18. Off-axial acoustic radiation force of repulsor and tractor bessel beams on a sphere.

    PubMed

    Silva, Glauber T; Lopes, J Henrique; Mitri, Farid G

    2013-06-01

    Acoustic Bessel beams are known to produce an axial radiation force on a sphere centered on the beam axis (on-axial configuration) that exhibits both repulsor and tractor behaviors. The repulsor and the tractor forces are oriented along the beam's direction of propagation and opposite to it, respectively. The behavior of the acoustic radiation force generated by Bessel beams when the sphere lies outside the beam's axis (off-axial configuration) is unknown. Using the 3-D radiation force formulas given in terms of the partial wave expansion coefficients for the incident and scattered waves, both axial and transverse components of the force exerted on a silicone- oil sphere are obtained for a zero- and a first-order Bessel vortex beam. As the sphere departs from the beam's axis, the tractor force becomes weaker. Moreover, the behavior of the transverse radiation force field may vary with the sphere's size factor ka (where k is the wavenumber and a is the sphere radius). Both stable and unstable equilibrium regions around the beam's axis are found, depending on ka values. These results are particularly important for the design of acoustical tractor beam devices operating with Bessel beams. PMID:25004483

  19. Vocational Agriculture Training Program: Safe Tractor and Farm Machinery Operation. Special Paper No. 8. Second Revision.

    ERIC Educational Resources Information Center

    Bobbitt, Frank; Doss, Howard

    The publication was prepared for the United States Office of Education for use by teachers who direct agricultural training programs in safe tractor operation and safe farm machinery operation that comply with the United States Department of Labor regulations on hazardous occupations in agriculture. Upon successful completion of these training…

  20. 49 CFR 399.207 - Truck and truck-tractor access requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 5 2011-10-01 2011-10-01 false Truck and truck-tractor access requirements. 399.207 Section 399.207 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL MOTOR CARRIER SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION FEDERAL MOTOR CARRIER SAFETY REGULATIONS EMPLOYEE SAFETY AND HEALTH STANDARDS...

  1. 76 FR 9495 - Airworthiness Directives; Air Tractor, Inc. Models AT-802 and AT-802A Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-18

    ..., amendment 39-16412 (75 FR 52255, August 25, 2010), for all Air Tractor Models AT-802 and AT- 802A airplanes... statutes, to fit regulatory and informational requirements to the scale of the businesses, organizations... actions. The RFA covers a wide range of small entities, including small businesses,...

  2. Space Shuttle Crawler Transporter Truck Shoe Qualification Tests and Analyses for Return-to-Flight

    NASA Technical Reports Server (NTRS)

    Margasahayam, Ravi N.; Meyer, Karl A.; Burton, Roy C.; Gosselin, Armand M.

    2005-01-01

    A vital element to Launch Complex 39 (LC39) and NASA's Kennedy Space Center (KSC) mobile launch transfer operation is a 3 million kilogram behemoth known as the Crawler Transporter (CT). Built in the 1960's, two CT's have accumulated over 1700+ miles each and have been used for the Apollo and the Space Shuttle programs. Recent observation of fatigue cracks on the CT shoes led to a comprehensive engineering, structural and metallurgical evaluation to assess the root cause that necessitated procurement of over 1000 new shoes. This paper documents the completed dynamic and compression tests on the old and new shoes respectively, so as to certify them for Space Shuttle's return-to-flight (RTF). Measured strain data from the rollout tests was used to develop stress/loading spectra and static equivalent load for qualification testing of the new shoes. Additionally, finite element analysis (FEA) was used to conduct sensitivity analyses of various contact parameters and structural characteristics for acceptance of new shoes.

  3. The inspection of a radiologically contaminated pipeline using a teleoperated pipe crawler

    SciTech Connect

    Fogle, R.F.; Kuelske, K.; Kellner, R.A.

    1995-08-01

    In the 1950s, the Savannah River Site built an open, unlined retention basin to temporarily store potentially radionuclide contaminated cooling water from a chemical separations process and storm water drainage from a nearby waste management facility that stored large quantities of nuclear fission byproducts in carbon steel tanks. The retention basin was retired from service in 1972 when a new, lined basin was completed. In 1978, the old retention basin was excavated, backfilled with uncontaminated dirt, and covered with grass. At the same time, much of the underground process pipeline leading to the basin was abandoned. Since the closure of the retention basin, new environmental regulations require that the basin undergo further assessment to determine whether additional remediation is required. A visual and radiological inspection of the pipeline was necessary to aid in the remediation decision making process for the retention basin system. A teleoperated pipe crawler inspection system was developed to survey the abandoned sections of underground pipelines leading to the retired retention basin. This paper will describe the background to this project, the scope of the investigation, the equipment requirements, and the results of the pipeline inspection.

  4. Bio-objects as “boundary crawlers:” the case of microRNAs

    PubMed Central

    Chrupek, Małgorzata; Siipi, Helena; Martinelli, Lucia

    2012-01-01

    Abstract microRNAs (miRNAs), short RNAs of 21-25 nucleotides, are implied in gene expression and regulation, in biological processes and in human pathologies including cancer. Since miRNAs of plant origin can survive digestion and cooking and enter in animal (including human) sera and tissues, their intervention in mammalian gene expression and regulation might be expected. Mouse experimental feeding, in fact, showed that a miRNA class (MIR168a) is involved in accumulation of the low-density lipoprotein (LDL), the major cholesterol-carrying lipoprotein of human plasma. Considering LDL’s role in atherosclerosis, a negative influence of miRNAs from food origin on our health may be expected. Here we concentrate on the miRNAs’ capability to cross inter-kingdom boundaries through the diet and acting as a “boundary crawler.” The boundary between plant and human is presented under a new perspective, where a new intimate relationship between two genomes – mammalian and plant – belonging to quite different kingdoms is proposed. The food’s role as molecule carrier in our health is also discussed. miRNAs, finally, are presented as an example of “bio-objects” with impact on both medical and cultural issues. PMID:22661143

  5. Evaluation of a tractor cab using real-time aerosol counting instrumentation.

    PubMed

    Hall, Ronald M; Heitbrink, William A; Reed, Laurence D

    2002-01-01

    Aerosol instrumentation was used to evaluate air infiltration into tractor cabs that are used to protect the agricultural worker during pesticide applications. Preliminary surveys were conducted on three different manufactured agriculture enclosures. The results of these preliminary surveys indicated that aerosols are entering the cab through leak sources or are being generated inside the cab. These results identified the need for in-depth field evaluations of tractor cabs to identify any leak sources. To evaluate the ability of tractor cabs to reduce operator air contaminant exposure, field evaluations were conducted on two tractor cabs. Specifically, we evaluated: 1) the particle size distribution and the effectiveness of the filter system; and 2) air infiltration into the cab. These evaluations were also conducted to demonstrate the ease and practicality of using optical particle counters to evaluate the ability of cabin filtration systems. Pesticide particle size distribution during an air blast spray operation was also evaluated during the study. The field tests were conducted on a John Deere 7000 series tractor cab (tractor manufacturer's cab) and a Nelson spraycab (retrofit cab). Both cabs were equipped with high efficiency particulate air (HEPA) filter media which were assumed to be 99.97 percent efficient at removing the test aerosol, atmospheric condensation nuclei. Thus, the major source of aerosols inside the cab was assumed to be leakage around filters at the seals. Using a portable dust monitor (PDM), the ratio of the outside to inside aerosol measurements was used to calculate a cab protection factor. During the evaluations, one PDM was placed inside the tractor cab (near the tractor operator) and one PDM was placed outside (near the air intake) to count particles. During the evaluations, the instruments were switched to prevent instrument bias from affecting the findings. The ratio of the two measurements (i.e., protection factor = outside

  6. Analysis of tractor-related deaths in North Carolina from 1979 to 1988.

    PubMed

    Bernhardt, J H; Langley, R L

    1999-01-01

    This descriptive study examined 342 fatalities involving tractors and attachments that occurred during a 10-year period in North Carolina from 1979 to 1988. Reports of the North Carolina Office of the Chief Medical Examiner and medical examiner's certificates of death were reviewed using the public health model of causation. Data were collected on characteristics of thefatally injured (host), including age, occupation, blood alcohol concentration and length of survival; characteristics of the injury event (environment), including type of accident, weather conditions and terrain; and characteristics of the agent, including both the tractor and attachments, if any, in place at the time of injury. Ninety-eight percent of the victims were male. Victims ages 65 and older accounted for 38 percent of fatal injuries, and 11 percent were 18 years of age or younger. Only slightly more than one-half of the victims (54 percent) were full- or part-time farmers. Forty-four percent of the deaths were to nonfarmers who were not in the act of farming. Nineteen percent of tested victims had a detectable blood alcohol level. Almost three-fourths of the victims died in the first hour after injury and 87 percent within the first 24 hours. In the majority of accidents, the tractor operator was a victim of a rollover or runover. This study provided detailed characterization of the fatally injured and, to the extent possible, the tractor involved and the injury event itself. However, additional methods of data collection are needed to provide further characterization of the injury event and the injury agent to design and support prevention programs for tractor users. PMID:11942561

  7. Sociomics! Using the IssueCrawler to map, monitor and engage with the global proteomics research network.

    PubMed

    McNally, Ruth

    2005-08-01

    We invite comment upon an experiment to locate proteomics on the WWW using a software tool called the IssueCrawler. We call our research "sociomics" because, like the bioscience omics, it is a semi-automated, computerised approach to the global analysis of data, whose computerised results can be integrated towards the development of a new "systems sociology" approach to the study of society. Our findings are that proteomics on the web is a scale-free network whose nodes display considerable "dynamic range". PMID:16035115

  8. a Decade of Improvement in Whole-Body Vibration and Low Back Pain for Freight Container Tractor Drivers

    NASA Astrophysics Data System (ADS)

    Nishiyama, K.; Taoda, K.; Kitahara, T.

    1998-08-01

    The authors' study in 1983 revealed that the whole-body vibration of the tractor units of freight containers was most hazardous in the back-to-chest directions (x-axis). The allowable exposure time was considerably shorter than that for heavy duty trucks. The low back pain (LBP) among the drivers seemed to be due to the long working hours and the ergonomically unsound tractor design, as well as the vibration. A preventative measure was the introduction of a tractor cab suspended by an air spring instead of a steel spring. In 1992, a follow-up field study was conducted. A personal vibration exposure meter developed by us measured the whole-body vibration on eight tractors. Eighty-nine triplets matched with the age and the years of driving tractors answered a questionnaire evaluation of the ergonomics of their tractor units.The comparison of the newest steel suspension vehicles to the old ones produced by the same motor company revealed that in thex-axis the vibration level had decreased by as much as 4 to 9 dB. Some tractors showed an increase in vibration in the buttocks-to-head direction (z-axis). However, such adverse changes seemed not to affect evaluations according to the fatigue-decreased proficiency boundary (FDP) and the exposure limit (EL) recommended in ISO 2631-1978. The present models, regardless of the type of suspension, changed the direction of the most hazardous vibration from thex-axis to thez-axis. However, the effect of the air-suspension was not so remarkable as expected. Among 40% of drivers seemed to exceed the FDP boundary during a day.The questionnaire study showed an improvement in the ergonomic evaluation of the tractors. The air suspension models seemed to induce less LBP than the steel suspension models.

  9. Quantifying driver's field-of-view in tractors: methodology and case study.

    PubMed

    Gilad, Issachar; Byran, Eyal

    2015-01-01

    When driving a car, the visual awareness is important for operating and controlling the vehicle. When operating a tractor, it is even more complex. This is because the driving is always accompanied with another task (e.g., plough) that demands constant changes of body postures, to achieve the needed Field-of-View (FoV). Therefore, the cockpit must be well designed to provide best FoV. Today, the driver's FoV is analyzed mostly by computer simulations of a cockpit model and a Digital Human Model (DHM) positioned inside. The outcome is an 'Eye view' that displays what the DHM 'sees'. This paper suggests a new approach that adds quantitative information to the current display; presented on three tractor models as case studies. Based on the results, the design can be modified. This may assist the engineer, to analyze, compare and improve the design, for better addressing the driver needs. PMID:26327259

  10. Heat-treatment by using induction heating on the Minsk Tractor Plant

    SciTech Connect

    Kosmovich, L.S.; Baranov, V.S.; Koshelenkov, K.N.; Fel'dman, L.Ya.

    1988-01-01

    The Minsk Tractor Plant uses a technique for hardening preceded by induction heating for more than 50% of its heat-treated parts made from 45, 40Kh, 38KhGs, and 33KhS steels. The majority of parts undergo heat-treatment on the machining lines. This method made it possible to develop and put into service an automatic device for strainless hardening of strips in the forced conditions. Improving and introducing this new technological process, equipment, and fittings for heat treatment by induction heating was found to increase the life of the tractor parts, reduce labor costs for their manufacture as well as increase savings in electricity and rolled materials.

  11. Co-Simulation Research of the Mechanical-Hydraulic-Control Coupling System of ITER Tractor

    NASA Astrophysics Data System (ADS)

    Yang, Xiuqing; Luo, Minzhou; Mei, Tao; Yao, Damao

    2009-06-01

    The virtual prototyping models of the mechanical, hydraulic and control system of the ITER tractor were built with CATIA, ADAMS and MATLAB/Simulink respectively according to its heavy load and high precision characteristics, and the data transfer between the different models was accomplished by the integration interface between different software. Consequently the virtual experimental platform for the multi-disciplinary co-simulation was established. A co-simulation study of the mechanical-hydraulic-control coupling system of the ITER tractor was carried out. The synchronization servo control of parallel hydraulic cylinders was implemented, and the tracking control of the preconcerted trajectory of the hydraulic cylinders was realized on the established experimental platform. This paper presents the optimization design and technology rebuilding for the complicated coupling system with its theoretic foundation and co-simulation virtual experimental platform.

  12. Tractor tire aspect ratio effects on soil bulk density and cone index

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A 580/70R38 tractor drive tire with an aspect ratio of 0.756 and a 650/75R32 tire with an aspect ratio of 0.804 were operated at two dynamic loads and two inflation pressures on a sandy loam and a clay loam with loose soil above a hardpan. Soil bulk density and cone index were measured just above t...

  13. Using Web Crawler Technology for Text Analysis of Geo-Events: A Case Study of the Huangyan Island Incident

    NASA Astrophysics Data System (ADS)

    Hu, H.; Ge, Y. J.

    2013-11-01

    With the social networking and network socialisation have brought more text information and social relationships into our daily lives, the question of whether big data can be fully used to study the phenomenon and discipline of natural sciences has prompted many specialists and scholars to innovate their research. Though politics were integrally involved in the hyperlinked word issues since 1990s, automatic assembly of different geospatial web and distributed geospatial information systems utilizing service chaining have explored and built recently, the information collection and data visualisation of geo-events have always faced the bottleneck of traditional manual analysis because of the sensibility, complexity, relativity, timeliness and unexpected characteristics of political events. Based on the framework of Heritrix and the analysis of web-based text, word frequency, sentiment tendency and dissemination path of the Huangyan Island incident is studied here by combining web crawler technology and the text analysis method. The results indicate that tag cloud, frequency map, attitudes pie, individual mention ratios and dissemination flow graph based on the data collection and processing not only highlight the subject and theme vocabularies of related topics but also certain issues and problems behind it. Being able to express the time-space relationship of text information and to disseminate the information regarding geo-events, the text analysis of network information based on focused web crawler technology can be a tool for understanding the formation and diffusion of web-based public opinions in political events.

  14. Gravity, two times, tractors, Weyl invariance, and six-dimensional quantum mechanics

    SciTech Connect

    Bonezzi, R.; Latini, E.; Waldron, A.

    2010-09-15

    Fefferman and Graham showed some time ago that four-dimensional conformal geometries could be analyzed in terms of six-dimensional, ambient, Riemannian geometries admitting a closed homothety. Recently, it was shown how conformal geometry provides a description of physics manifestly invariant under local choices of unit systems. Strikingly, Einstein's equations are then equivalent to the existence of a parallel scale tractor (a six-component vector subject to a certain first order covariant constancy condition at every point in four-dimensional spacetime). These results suggest a six-dimensional description of four-dimensional physics, a viewpoint promulgated by the 2 times physics program of Bars. The Fefferman-Graham construction relies on a triplet of operators corresponding, respectively, to a curved six-dimensional light cone, the dilation generator and the Laplacian. These form an sp(2) algebra which Bars employs as a first class algebra of constraints in a six-dimensional gauge theory. In this article four-dimensional gravity is recast in terms of six-dimensional quantum mechanics by melding the 2 times and tractor approaches. This parent formulation of gravity is built from an infinite set of six-dimensional fields. Successively integrating out these fields yields various novel descriptions of gravity including a new four-dimensional one built from a scalar doublet, a tractor-vector multiplet and a conformal class of metrics.

  15. Aerodynamic performance of a drag reduction device on a full-scale tractor/trailer

    NASA Astrophysics Data System (ADS)

    Lanser, Wendy R.; Ross, James C.; Kaufman, Andrew E.

    1991-09-01

    The effectiveness of an aerodynamic boattail on a tractor/trailer road vehicle was measured in the NASA Ames Research Center 80- by 120-Foot Wind Tunnel. Results are examined for the tractor/trailer with and without the drag reduction device. Pressure measurements and flow visualization show that the aerodynamic boattail traps a vortex or eddy in the corner formed between the device and the rear corner of the trailer. This recirculating flow turns the flow inward as it separates from the edges of the base of the trailer. This modified flow behavior increases the pressure acting over the base area of the truck, thereby reducing the net aerodynamic drag of the vehicle. Drag measurements and pressure distributions in the region of the boattail device are presented for selected configurations. The optimum configuration reduces the overall drag of the tractor/trailer combination by about 10 percent at a zero yaw angle. Unsteady pressure measurements do not indicate strong vortex shedding, although the addition of the boattail plates increases high frequency content of the fluctuating pressure.

  16. Realistic Autofarming Closed-Loop Tractor Control over Irregular Paths Using Kinematic GPS

    NASA Astrophysics Data System (ADS)

    Bell, Thomas; O'Connor, Michael; Jones, V. K.; Rekow, Andrew; Elkaim, Gabriel; Parkinson, Bradford

    1998-09-01

    High-precision 'autofarming' makes possible farming techniques previously impractical using metre-level Differential GPS-based control systems: techniques such as tape irrigation, the elimination of guess rows, and precise contour farming. A Carrier-Phase Differential gps positioning and attitude system with centimetre-level and 0·1° accuracy was installed in a large farm tractor. Four types of trajectories (lines, arcs, spirals, and curves) were identified as basic building blocks necessary to generate a 'global' trajectory for a realistic autofarming path. Information about each trajectory type was translated into reference state specifications that a linear controller used to control the tractor over velocities between 0·7 and 2·8 m/s to within approximately 6 cm (1 σ) without implement and 10 cm (1 σ) with implement on sloped terrain using a previously developed tractor model. These results are a significant step towards a realistic autofarming system because they not only demonstrate accurate control over various realistic operating speeds but over different types of trajectories necessary for a commercial system.

  17. Self-reported back pain in tractor drivers exposed to whole-body vibration.

    PubMed

    Boshuizen, H C; Bongers, P M; Hulshof, C T

    1990-01-01

    A postal questionnaire on symptoms of ill health and exposure to whole-body vibration was completed by 577 workers (response rate 79%) who were employed in certain functions by two companies 11 years before. The relation between the occupational history of driving vibrating vehicles (mainly agricultural tractors) and back pain has been analyzed. The prevalence of reported back pain is approximately 10% higher in the tractor drivers than in workers not exposed to vibration. The increase is mainly due to more pain in the lower back and more pain lasting at least several days. A vibration dose was calculated by assigning each vehicle driven a vibration magnitude, estimated on the base of vibration measurements. The prevalence of back pain increases with the vibration dose. The highest prevalence odds ratios are found for the more severe types of back pain. These prevalence odds ratios do not increase with the vibration dose. This might be due to health-related selection which is more pronounced for severe back pain than for back pain in general. The two components of the vibration dose, duration of exposure and estimated mean vibration magnitude, have also been considered separately. Back pain increases with duration of exposure but it does not increase with the estimated mean magnitude of vibration. This is probably due to the inaccuracy of this estimate. The higher prevalence of back pain in tractor drivers might be (partly) caused by whole-body vibration, but prolonged sitting and posture might also be of influence. PMID:2139012

  18. Coca-Cola Refreshments Class 8 Diesel Electric Hybrid Tractor Evaluation: 13-Month Final Report

    SciTech Connect

    Walkowicz, K.; Lammert, M.; Curran, P.

    2012-08-01

    This 13-month evaluation used five Kenworth T370 hybrid tractors and five Freightliner M2106 standard diesel tractors at a Coca Cola Refreshments facility in Miami, Florida. The primary objective was to evaluate the fuel economy, emissions, and operational field performance of hybrid electric vehicles when compared to similar-use conventional diesel vehicles. A random dispatch system ensures the vehicles are used in a similar manner. GPS logging, fueling, and maintenance records and laboratory dynamometer testing are used to evaluate the performance of these hybrid tractors. Both groups drive similar duty cycles with similar kinetic intensity (0.95 vs. 0.69), average speed (20.6 vs. 24.3 mph), and stops per mile (1.9 vs. 1.5). The study demonstrated the hybrid group had a 13.7% fuel economy improvement over the diesel group. Laboratory fuel economy and field fuel economy study showed similar trends along the range of KI and stops per mile. Hybrid maintenance costs were 51% lower per mile; hybrid fuel costs per mile were 12% less than for the diesels; and hybrid vehicle total cost of operation per mile was 24% less than the cost of operation for the diesel group.

  19. A newly developed snow vehicle (SM100S) for Antarctica. Part 4: Low temperature properties of crawler belt

    NASA Astrophysics Data System (ADS)

    Maekawa, Etsuji; Terayama, Yoshihide

    1992-11-01

    In order to discover a high cold-resistance material for use in the crawler belt of snow vehicles, the physical properties at very low temperatures of a recently developed material, isoprene/butadiene (70/30) random copolymer filled with carbon black, was investigated in comparison with a blended rubber NR (Natural Rubber) / BR (Butadiene Rubber) (65/35) as well as a currently used NR. It has been found that this material can keep rubber elasticity even at low temperatures below - 70 C, though it is somewhat inferior to the other two materials as to strengths such as stress-at-break and tear; and hence, it is considered as quite worthy of a practical test for a snow vehicle in the Antarctic area.

  20. Determination of influence factors and accident rates for the Armored Tractor/Safe Secure Trailer

    SciTech Connect

    Phillips, J.S.; Clauss, D.B.; Blower, D.F.

    1994-04-01

    Operating environments, such as road type, road location, and time of day, play an important role in the observed accident rates of heavy trucks used in general commerce. These same factors influence the accident rate of the Armored Tractor/Safe Secure Trailer (AT/SST) used by the Department of Energy to transport hazardous cargos within the continental United States. This report discusses the development of accident rate influence factors. These factors, based on heavy trucks used in general commerce, are used to modify the observed overall AT/SST accident rate to account for the different operating environments.

  1. Pathologic features of farm and tractor-related fatalities in children.

    PubMed

    Byard, R W; Gilbert, J; James, R; Lipsett, J

    1999-03-01

    A study of 15 childhood fatalities due to farm or tractor-related accidents demonstrated extensive injuries typified by crushing, evisceration, and amputation of limbs. Although these injuries are characteristic of industrial accidents in adults, such accidents do not commonly occur in children. However, the unique circumstance of the farm, which incorporates home and industrial environments, results in particularly severe patterns of injuries in accidental childhood deaths. A knowledge of the range of machines that are used and the environment of the farm facilitates assessment of the types of injuries that may be found at autopsy in cases of pediatric farm accident. PMID:10208343

  2. Structural dynamics modeling and testing of the Department of Energy tractor/trailer combination

    SciTech Connect

    Field, R.V. Jr.; Hurtado, J.E.; Carne, T.G.; Dohrmann, C.R.

    1996-12-31

    This study presents a combined analytical and experimental effort to characterize and improve the ride quality of the Department of Energy tractor/trailer combination. The focus is to augment the experimental test results with the use of a high quality computer model. The discussion includes an overview of the finite element model of the vehicle and experimental modal test results. System identification techniques are employed to update the mathematical model. The validated model is then used to illustrate the benefits of incorporating two major design changes, namely the switch from a separate cab/sleeper configuration to an integrated cab, and the use of a cab suspension system.

  3. Effects of the Bogie Mechanism on the Dynamic Behavior of Crawler-type Construction Machines in Traveling on Firm Grounds with Continuous Bumps

    NASA Astrophysics Data System (ADS)

    Abe, Masajiro; Nakagawa, Chikara; Nakamura, Shinya

    In crawler-type construction machines, flexible suspension system like bogie mechanism type suspension is used to reduce and disperse the load acting on the running gear and to absorb the vibration from uneven ground. However, the quantitative effects of the bogie are not so clear. In this paper, by using a modeling and simulation method for crawler-type construction machine with bogie mechanism, which is developed by the authors, in traveling on firm grounds with continuous bumps, representative simulation cases to analyze the dynamic behavior were conducted. Then K-type and X-type bogie as flexible suspension and locked K-type and X-type bogie as rigid suspension were selected. In two bump pitch cases, effects of the bogie mechanism introduction and the bogie type on the dynamic behavior of the machine, such as the lower rollers load and the bouncing and pitching behavior were shown quantitatively and discussed.

  4. Preventing tractor rollover fatalities: performance of the NIOSH autoROPS.

    PubMed

    Powers, J R; Harris, J R; Etherton, J R; Ronaghi, M; Snyder, K A; Lutz, T J; Newbraugh, B H

    2001-09-01

    Approximately 132 agricultural tractor overturn fatalities occur per year. The use of rollover protective structures (ROPS), along with seat belts, is the best known method for preventing these fatalities. One impediment to ROPS use, however, is low clearance situations, such as orchards and animal confinement buildings. To address the need for ROPS that are easily adapted to low clearance situations, the Division of Safety Research, National Institute for Occupational Safety and Health (NIOSH), developed an automatically deploying, telescoping ROPS (Auto-ROPS). The NIOSH AutoROPS consists of two subsystems. The first is a retractable ROPS that is normally latched in its lowered position for day-to-day use. The second subsystem is a sensor that monitors the operating angle of the tractor. Ifa rollover condition is detected by the sensor, the retracted ROPS will deploy and lock in the full upright position before ground contact. Static load testing and field upset tests of the NIOSH AutoROPS have been conducted in accordance with SAE standard J2194. Additionally, timed trials of the AutoROPS deployment mechanism were completed. The design of the retractable ROPS and sensor, as well as the results of the different testing phases are discussed. PMID:11565973

  5. Acoustic control in a tractor cabin using two optimally designed Helmholtz resonators

    NASA Astrophysics Data System (ADS)

    Driesch, Patricia L.; Koopmann, Gary H.

    2003-10-01

    A virtual design methodology is developed to minimize the noise in enclosures with optimally designed, passive, 20 acoustic absorbers (Helmholtz resonators). A series expansion of eigenfunctions is used to represent the acoustic=20 absorbers as external volume velocities, eliminating the need for a solution of large matrix eigenvalue problems. A determination of this type (efficient model/reevaluation approach) significantly increases the design possibilities when optimization techniques are implemented. As a full-scale demonstration, the acoustic response from 90-190 Hz of a tractor cabin was investigated. The lowest cabin mode proposes a significant challenge to a noise control engineer since its anti-node is located near the head of the operator and often generates unacceptable sound-pressure levels. Exploiting the low-frequency capability of Helmholtz resonators, lumped parameter models of these resonators were coupled to the enclosure via an experimentally determined acoustic model of the tractor cabin. The virtual design methodology uses gradient optimization techniques as a post-processor for the modeling and analysis of the unmodified acoustic interior to determine optimal resonator characteristics. Using two optimally designed Helmholtz resonators, potential energy was experimentally reduced by 3.4 and 10.3 dB at 117 and 167 Hz, respectively.

  6. Reduction of aerodynamic drag and fuel consumption for tractor-trailer vehicles

    NASA Technical Reports Server (NTRS)

    Muirhead, V. U.; Saltzman, E. J.

    1979-01-01

    Wind-tunnel tests were performed on a scale model of a cab-over-engine tractor-trailer vehicle and several modifications of the model. Results from two of the model configurations were compared with full-scale drag data obtained from similar configurations during coast-down tests. Reductions in fuel consumption derived from these tests are presented in terms of fuel quantity and dollar savings per vehicle year, based on an annual driving distance of 160,900 km (100,000 mi.). The projected savings varied from 13,001 (3435) to 25,848 (6829) liters (gallons) per year which translated to economic savings from $3435 to about $6829 per vehicle year for an operating speed of 88.5 km/h (55 mph) and wind speeds near the national average of 15.3 km/h (9.5 mph). The estimated cumulative fuel savings for the entire U.S. fleet of cab-over-engine tractor, van-type trailer combinations ranged from 4.18 million kl (26.3 million bbl) per year for a low-drag configuration to approximately twice that amount for a more advanced configuration.

  7. Development and implementation of thermal signature testing protocol of auxiliary power unit (APU) and diesel tractor

    NASA Astrophysics Data System (ADS)

    Jenkins, Chelsea L.; Bourne, Stefanie M.; Rowley, Matthew J.; Miles, Jonathan J.

    2004-04-01

    Thermal signature may be one of the defining factors in determining the applicability of fuel cell auxiliary power unit (APU) technology in military applications. Thermal characterization is important for military applications given that identification and detection may be accomplished through observation of its thermal signature. The operating modes and power takeoff operations of a vehicle will likely determine the thermal profile. The objective of our study was to develop and implement a protocol for quantifying the thermal characteristics of a methanol fuel cell and an idling tractor engine under representative characteristic operations. APU thermal characteristics are a special case for which standardized testing procedures do not presently exist. A customized testing protocol was developed and applied that is specific to an APU-equipped vehicle. Initial testing was conducted on the methanol APU-equipped Freightliner tractor using a high-performance radiometric infrared system. The APU profile calls for a series of infrared images to be collected at three different viewing angles and two different elevations under various loads. The diesel engine was studied in a similar fashion using seven different viewing angles and two different elevations. Raw data collected according to the newly developed methodology provided the opportunity for computer analysis and thermal profiling of both the fuel cell and the diesel engine.

  8. Rearward Visibility Issues Related to Agricultural Tractors and Self-Propelled Machinery: Contributing Factors, Potential Solutions.

    PubMed

    Ehlers, S G; Field, W E

    2016-01-01

    As the size, complexity, and speed of agricultural tractors and self-propelled machinery have increased, so have the visibility-related issues, placing significant importance on the visual skills, alertness, and reactive abilities of the operator. Rearward movement of large agricultural equipment has been identified in the literature as causing both fatalities and injuries to bystanders who were not visible to the operator and damage to both the machine and stationary objects. The addition of monitoring assistance, while not a new concept, has advanced significantly, offering agricultural machinery operators greater options for increasing their awareness of the area surrounding the machine. In this research, we attempt to (1) identify and describe the key contributors to agricultural machinery visibility issues, i.e., operator-related and machine-related factors, and (2) enumerate and evaluate the potential solutions being offered that address these factors. Enhanced operator safety and efficiency should result from a better understanding of the efforts to solve the visibility problems inherent in large tractors and self-propelled agricultural machinery. PMID:27024992

  9. Preventing tractor rollover fatalities: performance of the NIOSH AutoROPS

    PubMed Central

    Powers, J; Harris, J; Etherton, J; Ronaghi, M; Snyder, K; Lutz, T; Newbraugh, B

    2001-01-01

    Approximately 132 agricultural tractor overturn fatalities occur per year. The use of rollover protective structures (ROPS), along with seat belts, is the best known method for preventing these fatalities. One impediment to ROPS use, however, is low clearance situations, such as orchards and animal confinement buildings. To address the need for ROPS that are easily adapted to low clearance situations, the Division of Safety Research, National Institute for Occupational Safety and Health (NIOSH), developed an automatically deploying, telescoping ROPS (AutoROPS). The NIOSH AutoROPS consists of two subsystems. The first is a retractable ROPS that is normally latched in its lowered position for day-to-day use. The second subsystem is a sensor that monitors the operating angle of the tractor. If a rollover condition is detected by the sensor, the retracted ROPS will deploy and lock in the full upright position before ground contact. Static load testing and field upset tests of the NIOSH AutoROPS have been conducted in accordance with SAE standard J2194. Additionally, timed trials of the AutoROPS deployment mechanism were completed. The design of the retractable ROPS and sensor, as well as the results of the different testing phases are discussed. PMID:11565973

  10. 29 CFR 1928.53 - Protective enclosures for wheel-type agricultural tractors-test procedures and performance...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... specified in 29 CFR 1928.51. (b) Types of tests. All protective enclosures for wheel-type agricultural... following definitions shall apply: W = Tractor weight (see 29 CFR 1928.51(a)) in lb (W ′ in kg); E is... and point of load application for both side and rear shall be the same as specified in 29 CFR...

  11. 29 CFR 1928.51 - Roll-over protective structures (ROPS) for tractors used in agricultural operations.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 9 2013-07-01 2013-07-01 false Roll-over protective structures (ROPS) for tractors used in agricultural operations. 1928.51 Section 1928.51 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) OCCUPATIONAL SAFETY AND HEALTH STANDARDS FOR AGRICULTURE...

  12. A powered roller/crimper for walk-behind tractors to terminate cover crops in conservation agriculture

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Roller/crimper implements have been used in large conservation farming systems to terminate cover crops near maturity and flatten them down to create a mulch through which cash crops can be planted directly into the cover residue. On small farms, tractors are usually small and less powerful relative...

  13. 29 CFR 1928.52 - Protective frames for wheel-type agricultural tractors-test procedures and performance requirements.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... to 5 mph (4.8 to 8.0 kph) at maximum governed engine rpm by driving forward directly up a minimum slope of 60° ±5° as shown in Figure C-11, or by an alternative equivalent means. The engine clutch may... CFR 1928.51. (b) Types of tests. All protective frames for wheel-type agricultural tractors shall...

  14. 29 CFR 1928.52 - Protective frames for wheel-type agricultural tractors-test procedures and performance requirements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... to 5 mph (4.8 to 8.0 kph) at maximum governed engine rpm by driving forward directly up a minimum slope of 60° ±5° as shown in Figure C-11, or by an alternative equivalent means. The engine clutch may... CFR 1928.51. (b) Types of tests. All protective frames for wheel-type agricultural tractors shall...

  15. 29 CFR 1928.52 - Protective frames for wheel-type agricultural tractors-test procedures and performance requirements.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... to 5 mph (4.8 to 8.0 kph) at maximum governed engine rpm by driving forward directly up a minimum slope of 60° ± 5° as shown in Figure C-11, or by an alternative equivalent means. The engine clutch may... CFR 1928.51. (b) Types of tests. All protective frames for wheel-type agricultural tractors shall...

  16. 29 CFR 1928.53 - Protective enclosures for wheel-type agricultural tractors-test procedures and performance...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... specified in 29 CFR 1928.51. (b) Types of tests. All protective enclosures for wheel-type agricultural... following definitions shall apply: W = Tractor weight (see 29 CFR 1928.51(a)) in lb (W ′ in kg); E is... and point of load application for both side and rear shall be the same as specified in 29 CFR...

  17. Tractor_DB (version 2.0): a database of regulatory interactions in gamma-proteobacterial genomes.

    PubMed

    Pérez, Abel González; Angarica, Vladimir Espinosa; Vasconcelos, Ana Tereza R; Collado-Vides, Julio

    2007-01-01

    The version 2.0 of Tractor_DB is now accessible at its three international mirrors: www.bioinfo.cu/Tractor_DB, www.tractor.lncc.br and http://www.ccg.unam.mx/tractorDB. This database contains a collection of computationally predicted Transcription Factors' binding sites in gamma-proteobacterial genomes. These data should aid researchers in the design of microarray experiments and the interpretation of their results. They should also facilitate studies of Comparative Genomics of the regulatory networks of this group of organisms. In this paper we describe the main improvements incorporated to the database in the past year and a half which include incorporating information on the regulatory networks of 13-increasing to 30-new gamma-proteobacteria and developing a new computational strategy to complement the putative sites identified by the original weight matrix-based approach. We have also added dynamically generated navigation tabs to the navigation interfaces. Moreover, we developed a new interface that allows users to directly retrieve information on the conservation of regulatory interactions in the 30 genomes included in the database by navigating a map that represents a core of the known Escherichia coli regulatory network. PMID:17088283

  18. Human hand-transmitted vibration measurements on pedestrian controlled tractor operators by a laser scanning vibrometer.

    PubMed

    Deboli, R; Miccoli, G; Rossi, G L

    1999-06-01

    A first application of a new measurement technique to detect vibration transmitted to the human body in working conditions is presented. The technique is based on the use of a laser scanning vibrometer. It was previously developed, analysed and tested using laboratory test benches with electrodynamical exciters, and comparisons with traditional measurement techniques based on accelerometers were made. First, results of tests performed using a real machine generating vibration are illustrated. The machine used is a pedestrian-controlled tractor working in a fixed position. Reference measurements by using the accelerometer have been simultaneously performed while scanning the hand surface by the laser-based measurement system. Results achieved by means of both measurement techniques have been processed, analysed, compared and used to calculate transmissibility maps of the hands of three subjects. PMID:10340028

  19. Aerodynamic drag reduction apparatus for gap-divided bluff bodies such as tractor-trailers

    DOEpatents

    Ortega, Jason M.; Salari, Kambiz

    2006-07-11

    An apparatus for reducing the aerodynamic drag of a bluff-bodied vehicle such as a tractor-trailer in a flowstream, the bluff-bodied vehicle of a type having a leading portion, a trailing portion connected to the leading portion, and a gap between the leading and trailing portions defining a recirculation zone. The apparatus is preferably a baffle assembly, such as a vertical panel, adapted to span a width of the gap between the leading and trailing portions so as to impede cross-flow through the gap, with the span of the baffle assembly automatically adjusting for variations in the gap width when the leading and trailing portions pivot relative to each other.

  20. A statistical description of the types and severities of accidents involving tractor semi-trailers

    SciTech Connect

    Clauss, D.B.; Wilson, R.K.; Blower, D.F.; Campbell, K.L.

    1994-06-01

    This report provides a statistical description of the types and severities of tractor semi-trailer accidents involving at least one fatality. The data were developed for use in risk assessments of hazardous materials transportation. Several accident databases were reviewed to determine their suitability to the task. The TIFA (Trucks Involved in Fatal Accidents) database created at the University of Michigan Transportation Research Institute was extensively utilized. Supplementary data on collision and fire severity, which was not available in the TIFA database, were obtained by reviewing police reports for selected TIFA accidents. The results are described in terms of frequencies of different accident types and cumulative distribution functions for the peak contact velocity, rollover skid distance, fire temperature, fire size, fire separation, and fire duration.

  1. Impacts of tug and debris sizes on electrostatic tractor charging performance

    NASA Astrophysics Data System (ADS)

    Hogan, Erik A.; Schaub, Hanspeter

    2015-01-01

    Active debris removal techniques enable relocating noncooperative geosynchronous (GEO) debris objects into graveyard orbits. One proposed method is the electrostatic tractor concept. Here a tug vehicle approaches a target debris object and emits an electron beam onto the debris. The charging that results yields an attractive electrostatic force that is used to tow the debris object into a new orbit. In this study, the impacts of relative sizing between tug and debris on the efficacy of this charge transfer process are considered. By applying a charging model and incorporating nominal, quiet GEO space weather conditions, limitations on the size ratio that preclude charge transfer are identified for different levels of beam energy. The resulting electrostatic forces and impacts on reorbiting performance are studied. The results indicate that a larger tug vehicle will enable the tugging of a broader range of debris sizes, and that the tug size should be roughly as large as the expected debris size.

  2. Acoustical pulling force on rigid spheroids in single Bessel vortex tractor beams

    NASA Astrophysics Data System (ADS)

    Mitri, F. G.

    2015-11-01

    The theoretical formalism for acoustical Bessel vortex (helicoidal) tractor beams and results presented here are the first to demonstrate the emergence of a pulling force of attraction on non-spherical oblate and prolate rigid spheroidal particles centered on the beam's axis of wave propagation. Numerical predictions for the axial acoustic radiation force illustrate the theory with particular emphasis on the aspect ratio of the spheroid, the half-cone angle and order of the beam, as well as the dimensionless size parameter. It is demonstrated here that the Bessel vortex beam parameters may be tailored in such a way that the spheroid is pulled against the forward linear momentum density flux associated with the incoming waves. Those results potentially suggest the use of Bessel vortex beams in the development of emergent technologies for non-contact remote sampling and particle characterization.

  3. [The effect of occupational exposure to noise among tractor drivers: assessment based on 'noise threshold'].

    PubMed

    Solecki, L

    1998-01-01

    The effects of occupational exposure to noise was analysed among operators of agricultural tractors (n = 172). The assessment was based on a parameter called 'noise immission level' (dose connected with the period of employment). The study showed that the correlation between hearing loss and noise immission dose was stronger than that between hearing loss and the period of employment. Equations of simple regression presented in this paper allow us to make a prognosis concerning the risk of occupational deafness and to develop the system of the prevention interventions. The results obtained indicated that the parameter of hygiene evaluation of exposure to noise, called 'noise immission level' should be used more frequently for the noise measurement, especially in the prevention of occupational diseases. PMID:10204143

  4. The Effect of Propellers and Nacelles on the Landing Speeds of Tractor Monoplanes

    NASA Technical Reports Server (NTRS)

    Windler, Ray

    1932-01-01

    This paper reports wind-tunnel tests giving the lift coefficients of large-scale wing-nacelle combinations both with and without the propeller. The tests were made to show the effect of nacelles, and idling and stopped propellers on the landing speeds of tractor monoplanes. Four types of nacelles with various cowlings were used in numerous positions with respect to both a Clark Y and a thick airfoil. The effect of both the idling and stopped propeller on lift, and consequently on landing speed, was negligible. A nacelle with exposed engine cylinders when placed directly in front of an airfoil caused a slight reduction in lift, consequently an increase in landing speed, over the condition with the wing alone. With this exception no appreciable effect on landing speed was indicated for any of the other combinations.

  5. Computational Flow Modeling of a Simplified Integrated Tractor-Trailer Geometry

    SciTech Connect

    Salari, K; McWherter-Payne, M

    2003-09-15

    For several years, Sandia National Laboratories and Lawrence Livermore National Laboratory have been part of a consortium funded by the Department of Energy to improve fuel efficiency of heavy vehicles such as Class 8 trucks through aerodynamic drag reduction. The objective of this work is to demonstrate the feasibility of using the steady Reynolds-Averaged Navier-Stokes (RANS) approach to predict the flow field around heavy vehicles, with special emphasis on the base region of the trailer, and to compute the aerodynamic forces. In particular, Sandia's computational fluid dynamics code, SACCARA, was used to simulate the flow on a simplified model of a tractor-trailer vehicle. The results are presented and compared with NASA Ames experimental data to assess the predictive capability of RANS to model the flow field and predict the aerodynamic forces.

  6. Computational flow modeling of a simplified integrated tractor-trailer geometry.

    SciTech Connect

    McWherter-Payne, Mary Anna; Salari, Kambiz

    2003-09-01

    For several years, Sandia National Laboratories and Lawrence Livermore National Laboratory have been part of a consortium funded by the Department of Energy to improve fuel efficiency of heavy vehicles such as Class 8 trucks through aerodynamic drag reduction. The objective of this work is to demonstrate the feasibility of using the steady Reynolds-Averaged Navier-Stokes (RANS) approach to predict the flow field around heavy vehicles, with special emphasis on the base region of the trailer, and to compute the aerodynamic forces. In particular, Sandia's computational fluid dynamics code, SACCARA, was used to simulate the flow on a simplified model of a tractor-trailer vehicle. The results are presented and compared with NASA Ames experimental data to assess the predictive capability of RANS to model the flow field and predict the aerodynamic forces.

  7. On the optimum ride control of a stochastic model of a tractor-semitrailer vehicle

    NASA Astrophysics Data System (ADS)

    ElMadany, M. M.; Samaha, M. E.

    1992-07-01

    A systematic approach based on stochastic optimal control and estimation theories for the optimal design of active suspension systems for a tractor-semitrailer vehicle is presented. The vehicle-road system dynamics combined with the human perception of random vibrations are cast in the standard linear quadratic Gaussian format. The time delays of the stochastic excitation process of the multi-axled vehicle are represented by a first order Padé approximation. The optimal controller/observer is derived which minimizes the mean-squared values of performance variables reflecting the human comfort, cargo safety, suspension working space, roadholding ability and control forces. The advantages of optimally controlled suspension systems over their passive counterparts are indicated.

  8. A Second New Species of Ice Crawlers from China (Insecta: Grylloblattodea), with Thorax Evolution and the Prediction of Potential Distribution

    PubMed Central

    Bai, Ming; Jarvis, Karl; Wang, Shu-Yong; Song, Ke-Qing; Wang, Yan-Ping; Wang, Zhi-Liang; Li, Wen-Zhu; Wang, Wei; Yang, Xing-Ke

    2010-01-01

    Modern grylloblattids are one of the least diverse of the modern insect orders. The thorax changes in morphology might be associated with the changes of the function of the forelegs, wing loss, changes in behavior and adaptation to habitat. As temperature is the main barrier for migration of modern grylloblattids, the range of each species is extremely limited. The potential distribution areas of grylloblattids remain unclear. A second new species of ice crawlers (Insecta: Grylloblattodea), Grylloblattella cheni Bai, Wang et Yang sp. nov., is described from China. The distribution map and key to species of Grylloblattella are given. A comparison of the thorax of extant and extinct Grylloblattodea is presented, with an emphasis on the pronotum using geometric morphometric analysis, which may reflect thorax adaptation and the evolution of Grylloblattodea. Potential global distribution of grylloblattids is inferred. Highly diversified pronota of extinct Grylloblattodea may reflect diverse habitats and niches. The relatively homogeneous pronota of modern grylloblattids might be explained by two hypotheses: synapomorphy or convergent evolution. Most fossils of Grylloblattodea contain an obviously longer meso- and metathorax than prothorax. The length of the meso- and metathorax of modern grylloblattids is normally shorter than the prothorax. This may be associated with the wing loss, which is accompanied by muscle reduction and changes to the thoracic skeleton system. Threats to grylloblattids and several conservation comments are also provided. PMID:20877572

  9. Occupational hearing loss among selected farm tractor operators employed on large multiproduction farms in Poland.

    PubMed

    Solecki, L

    1998-01-01

    A specially selected group of 45 farm tractor drivers were examined in order to estimate the degree of occupational hearing loss. The drivers, aged 21-50 years, were employed on multiproduction farms. The study showed that the operators under study had statistically worse hearing within the range of high frequencies (3-6 kHz), especially those aged over 30 years, compared to the control group of the same age. An intolerable hearing loss (over 20 dB) was noted among 56% of operators within the highest frequency range (3, 4 and 6 kHz), and among 22% of operators in the range of medium frequencies (0.5, 1, 2 and 3 kHz), with no hearing loss observed in the control group. Based on analysis of data concerning all operators it was noted that age and the period of employment in agriculture were highly correlated with hearing loss (r = 0.45-0.57). A series of correlations and linear regression analyses, conducted in two age intervals, showed that in the group of young operators (under 35 years) a statistically significant, strong correlation was observed between hearing loss and the period of employment (right ear: r = 0.60-0.65), whereas in the older age group (over 35 years) hearing loss was more strongly correlated with age than with the period of employment, although this correlation was not statistically significant. The results obtained confirmed that the detected hearing loss among operators of farm tractors was caused by exposure to occupational noise present on farms. PMID:9637996

  10. Steering a Tractor by Means of an EMG-Based Human-Machine Interface

    PubMed Central

    Gomez-Gil, Jaime; San-Jose-Gonzalez, Israel; Nicolas-Alonso, Luis Fernando; Alonso-Garcia, Sergio

    2011-01-01

    An electromiographic (EMG)-based human-machine interface (HMI) is a communication pathway between a human and a machine that operates by means of the acquisition and processing of EMG signals. This article explores the use of EMG-based HMIs in the steering of farm tractors. An EPOC, a low-cost human-computer interface (HCI) from the Emotiv Company, was employed. This device, by means of 14 saline sensors, measures and processes EMG and electroencephalographic (EEG) signals from the scalp of the driver. In our tests, the HMI took into account only the detection of four trained muscular events on the driver’s scalp: eyes looking to the right and jaw opened, eyes looking to the right and jaw closed, eyes looking to the left and jaw opened, and eyes looking to the left and jaw closed. The EMG-based HMI guidance was compared with manual guidance and with autonomous GPS guidance. A driver tested these three guidance systems along three different trajectories: a straight line, a step, and a circumference. The accuracy of the EMG-based HMI guidance was lower than the accuracy obtained by manual guidance, which was lower in turn than the accuracy obtained by the autonomous GPS guidance; the computed standard deviations of error to the desired trajectory in the straight line were 16 cm, 9 cm, and 4 cm, respectively. Since the standard deviation between the manual guidance and the EMG-based HMI guidance differed only 7 cm, and this difference is not relevant in agricultural steering, it can be concluded that it is possible to steer a tractor by an EMG-based HMI with almost the same accuracy as with manual steering. PMID:22164006