Adaptive control of a farm tractor with varying yaw dynamics accounting for actuator dynamics and saturations

This paper presents an adaptive control system implemented on an automatically steered farm tractor. The yaw dynamics of the tractor are time varying due to different attached implements and soil conditions; therefore, a model reference adaptive control (MRAC) system is developed to automatically adjust the feed-forward yaw rate controller to changes in the current yaw plant. The MRAC algorithm is next modified from itpsilas original form to account for steering actuator dynamics and nonlinearities. Simulated results are presented that demonstrate the algorithmpsilas performance under ideal conditions. Experimental results are presented that show that the algorithm performs well on a real system with changing yaw dynamics. Finally, experimental results are shown that demonstrate improved tracking performance verses a fixed-gain configuration.