Path-tracking Robust Model Predictive Control of an Autonomous Steering System Using LMI Optimization With Independent Constraints Enforcement

Autonomous vehicles face their toughest challenge when navigating harsh road conditions due to continuous changes in cornering coefficients and vehicle velocity. To address this issue, this paper proposes a method for robust control of an autonomous steering system, incorporating independent constraint enforcement to enhance safe driving. Firstly, parameter uncertainties, including the front and rear cornering stiffness of the tires and the variations in vehicle velocity, are modeled as a polytope. This modeling approach enables the consideration of worst-case scenarios for uncertain parameters. Secondly, a robust model predictive control is designed based on the Lyapunov stability theorem, ensuring stability across all possible polytope vertices. Following that, independent constraint enforcement is implemented, including state and input control variables, to guarantee driving safety. Finally, various scenario simulations are conducted to validate the effectiveness of the proposed method.