Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: March 5, 2009
Publication Date: June 5, 2009
Citation: Way, T.R. 2009. Single Wheel Testers, Single Track Testers, and Instrumented Tractors. In: Upadhyaya, S.K., Chancellor, W.J., Perumpral, J.V., Wulfsohn, D. and Way, T.R., editors. Advances in Soil Dynamics. 3(2):253-271. Interpretive Summary: Traction of agricultural tractors and other off-road vehicles is important in allowing these vehicles to perform their desired tasks. Improvements in the efficiency with which these vehicles convert engine power to the power actually used in pulling an implement or other load are important in conserving energy, improving fuel efficiency, and reducing operating costs. Single wheel testers are machines that power a single tire or wheel on soil and measure the pulling force developed, and other operating characteristics, of the tire or wheel. Single track testers are machines that measure similar variables for a single track of a tracked vehicle such as a rubber track tractor or bulldozer. Designs and operating characteristics of various single tire and single track testers that have been developed by researchers are described. Also, sensors and instrumentation that have been used on agricultural tractors for determining traction forces and other tractive performance variables of tractors are described.
Technical Abstract: 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, including effects of tires and tracks on soil compaction and soil disturbance. Information is presented describing the designs and operating characteristics of several single tire testers and single track testers. Some of these testers have been used in soil bins, some in the field, and some in both soil bins and the field. Tractive performance of a single tire or single track is commonly evaluated based on net traction, tractive efficiency, and travel reduction. Tractive performance of a tractor is often evaluated based on drawbar pull, tractive efficiency of the whole tractor, power delivery efficiency, and travel reduction. Variables that are measured to quantify these parameters include forward velocity, axle angular velocity, axle torque, and forces used in determining net traction or drawbar pull. Instrumentation for measuring these variables for single wheel testers, single track testers, and instrumented tractors, is described.