1988 Volume 50 Issue 6 Pages 35-44
By remodeling an existing tractor, a tractor for sloping ground was manufactured for trial. A suspension of the front wheels was composed of parallel links. The trailing arm type suspensions serving as the final drive unit were used for the rear wheels. On the rear part of the tractor, a parallel link was installed, to which a three-point link hitch was attached. As the sensors for attitude control, three sensing devices were taken up. These are a pendulum accompanied by a damper, compound pendulums and all hydraulic servo valve operated by acceleration. We carried out the attitude control test, and the response of inclination compensation of the tractor was examined. Since the natural frequency of the pendulum with a damper is low, the sawtooth shape of swing angle owing to attitude control was observed. Compound pendulums were particularly effective for unsteady running such as sudden start-up and running over obstacles. Since the servo valve sensor has the high natural frequency, insufficient flow rate was apt to occur, and the phase was lagged, bus it accomplished a smooth control, and showed avery high stability in unsteady running.
