Active ground vehicle control with use of a super-twisting algorithm in the presence of parameter variations

In this paper, we consider a vehicle equipped with active front steer and rear torque vectoring. While the former adds an incremental steer angle to the driver´s input, the latter imposes a torque by means of the rear axle. The active front steer control is actuated through the front tires, while the rear torque vectoring can be actuated through the rear tires. A nonlinear controller using the super-twisting algorithm is designed in order to track in finite time lateral and yaw angular velocity references. We consider one estimation method, given in the literature, to estimate the tire-road coefficient, and we design a dynamic controller to estimate the perturbing terms due to the vehicle´s mass and inertia variations, and due to the variation of the tire parameters. Comparisons with a simple PI-based controller are done, and some simulation results highlight the advantages of the proposed controller.