Low-Complexity Control for Uncertain SbW Systems With Time-Varying Nonlinearity and Prescribed Tracking Performance

This article addresses a tracking performance control problem for steer-by-wire (SbW) systems with model uncertainty and time-varying nonlinearity (e.g., time-varying longitudinal dynamics and nonlinear lateral force). First, considering the coupling of vehicular lateral and longitudinal dynamics and the time-varying nonlinearities of tire forces, a novel mathematical model of SbW systems is presented. Second, without introducing intelligent approximators and adaptive techniques, a low-complexity prescribed performance control method is proposed for SbW systems based on robust control theory and barrier function methods. Third, theoretical analysis indicates that the tracking error of SbW systems can be driven to converge to a prescribed neighborhood of the origin within a preset time, and all signals of the closed-loop systems are semiglobally uniformly bounded. Finally, simulations and experiments are provided to validate the effectiveness of the proposed methods.