Speed Control for Robust Path-Tracking for Automated Vehicles at the Tire-Road Friction Limit
At the limit of tire-road friction, steering becomes an ineffective control input for tracking a desired path. In challenging automated driving scenarios, conventional lateral control through steering could therefore lead to road departures or hinder successful evasive maneuvers. Conservative path planning might prevent the occurrence of uncontrollable path-tracking dynamics; however, not using the full tire-force potential can also impede a successful emergency maneuver. This paper presents a novel control framework for consistent and full tire-force utilization with slip-angle based steering control, combined with explicit control of the path-tracking dynamics through longitudinal speed feedback. Experimental results with a full-scale automated race car demonstrate the framework achieving path tracking with consistent tire-force utilization, even when the estimate of available tire-road friction is inaccurate, while a conventional control architecture either underutilizes the tire-force potential, or slides off the path when friction is overestimated.
14th International Symposium on Advanced Vehicle Control (AVEC 2018)