Design of a Dynamic Surface Controller for Vehicle Sideslip Angle During Autonomous Drifting

This paper presents the design and experimental implementation of a dynamic surface controller for sideslip angle during autonomous drifting of a rear wheel drive vehicle. In this design, yaw rate is used as a synthetic input to control the vehicle's sideslip dynamics, and yaw rate is in turn controlled through coordination of the front tire lateral force (steering) and rear tire longitudinal force (drive). This input coordination is designed to increase rear tire saturation in order to maintain controllability of the vehicle via the front tire lateral force. This reflects a stability-controllability tradeoff that is characteristic of the steady state conditions corresponding to drifting and could have interesting applications to trajectory control when a vehicle's handling limits have been exceeded. The control technique has been implemented on P1, a student-built by-wire testbed, and shown to successfully achieve robust, sustained drifts.