Adaptive steering control of a farm tractor with varying yaw rate properties

This paper presents a novel application of a model reference adaptive control (MRAC) system to control the lateral position of a farm tractor tracking a straight path. Farm tractors can be configured with various implements, and the tractor yaw rate dynamics vary with each implement. It is desired that the lateral position response of the farm tractor remain consistent with respect to different implement configurations. Therefore, a MRAC system is implemented on the farm tractor to compensate for yaw rate plant variations by adapting the feed‐forward yaw rate controller. Simulation results of the algorithm are shown that display poor performance due to neglected steering actuator dynamics and saturation. Modifications are made to the algorithm to account for the steering actuator properties, and more simulated results are presented that display ideal performance. Finally, the MRAC algorithm is implemented on a John Deere 8420 farm tractor, and experimental results are presented.