Lateral Control of Heavy Duty Vehicles for Automated Highway System: Experimental Study on a Tractor Semi-trailer California PATH Working Paper UCB-ITS-PWP-2000-1 CALIFORNIA PARTNERS FOR ADVANCED TRANSIT AND HIGHWAYS

This report presents achievements of the MOU 313. “Lateral Control of Heavy Duty Vehicles for Automated Highway Systems” in the year 1998-1999. The goal of the project is to demonstrate lane following by automatic steering for tractor semi-trailer vehicles. Towards this goal, a class eight truck and a 45 feet long trailer were instrumented. The hardware development was a major effort in this year and is presented in detail. The actuators installed for lateral control were steering for and brake actuators. The open loop response of the steering actuator was studied in frequency domain. Based on this response, a minor loop controller is designed for the steering actuator loop. Accelerometers and gyroscopes were installed on the vehicle. The acceleration and yaw response of the vehicle to the road wheel angle was studied in a series of open loop tests. The results of the open loop tests are presented. Previous PATH research (1993-1996) has resulted in the design of several nonlinear controllers for lateral control of heavy vehicles. Nevertheless, from the point of view of preliminary implementation, two linear controllers, one based on classical loop shaping and the other based on optimal ∞ H loop shaping were designed. In addition, a nonlinear Sliding Mode Control for robustness to parametric and model uncertainties was designed. Experimental implementation of the linear controller was accomplished last year for speeds up to 45mph. Results of this experiment are presented.