Robust Position and Velocity Tracking Control of a Four-wheel Drive and Four-wheel Steered Electric Vehicle

The scope of this paper is the design and evaluation of a robust position and velocity tracking control of a four-wheel drive and four-wheel steered electric vehicle (4WD4WS EV). In an autonomous setup, an $\mathcal{H}_{\infty}$-controller based on the normalized coprime factor synthesis followed by a flat velocity control with an asymptotic stable tracking error is designed. Optimized force control allocation (CA) is supported by state of the art methods enhanced with the Redistributed Pseudoinverse (RPI) algorithm leading to a robust force distribution in case of actuator failure. The presented methods are applied to a continuous maneuver sequence covering parking as well as the double lane change and the weave test. Realistic and nonlinear disturbances on the steering and drive are considered. Therefore, a high gain observer coupled with SISO-control for each wheel supplements the cascaded control architecture. The results, considering measurement noise of the considered sensors, are discussed. For the given context, such a comprehensive controller structure has not been proposed or studied sufficiently.