Attitude control mechanism for the three-point linkage hitch system of the hillside-tractor

Abstract An experimental hillside-tractor has already been developed by remodeling the running gear of a conventional tractor. The attitude of the tractor was controlled levelly by driving the trailingarm style rear suspension with a hydraulic cylinder. At the rear of the tractor, the parallelogram link for the three-point linkage hitch system was built and the displacement of the hydraulic cylinder to the lower link of the parallelogram was transmitted by wire. Although we had tested the experimental tractor in rotary cultivation, the special adjustment for setting the combination position of the wire was necessary. Moreover, a rational method and principle of the wire combination had been uncertain. Thus, a relational equation composed of an attitude control compensation angle of the tractor and a displacement of a hydraulic cylinder was expressed by the link mechanism in this report. As a result, the measurement of the compensation angle became possible. Simultaneously, the authors clarified the attitude control mechanism of the three-point linkage hitch system by a test where one side of the link was set to be parallel to the testing slope.