An Input-Output Linearization-Based Robust Controller for Single-Track Models With Steering Actuator Delays

Input-output linearization is a powerful analytical tool to support the design of controllers for vehicles characterized by nonholonomic constraints. Nonetheless, the presence of actuator dynamics and of significant delays, particularly in the steering actuation, can significantly hamper the applicability of this technique. This article proposes an extension to an input-output linearization approach presented in the literature, which allows for including the actuator dynamics into the linearization law, and to compensate for the effect of delays and nonidealities on the linearized system, introducing a further control action, designed with the advanced gain scheduling technique. As a result, a linear time-invariant decoupled system is obtained, which allows us to design the trajectory tracking controller using linear control tools. Simulation results, based on three different vehicle simulators, ranging from a single-track model with linear and nonlinear tire models to a dual-track model, are also presented. The performance and robustness of the inner controller, composed of the linearizing law and the advanced gain scheduling controller, are thoroughly analyzed and compared with the results obtained using the former input-output linearization available in the literature. Furthermore, the results of the application of the proposed control framework as part of a trajectory tracking controller show the efficacy of the proposal.