Control of a guidance system for an agricultural tractor consists of three loops: steering angle control, yaw rate control, and lateral position control. Uncertainties inevitably exist in the models of plants used for control. This paper addresses, for the first time, the implementation of Quantitative Feedback Theory (QFT) method to the design of a robust controller for an agricultural tractor’s yaw dynamics. The design is based on a modified bicycle model in which the parametric uncertainties are due to the mass and forward speed variations. Simulation shows that the control system behaves successfully in meeting the defined performance criteria. Also, the designed controller and corresponding pre-filter are low order
