Homogeneous domination-based active shimmy control method for electric vehicle with hub motors considering unknown sensor measurement error and nonlinearity

Vehicles may generate wheel shimmy during motion, affecting driving stability and comfort. The use of hub motors increases the unsprung mass of vehicles, exacerbating this issue. How to actively eliminate wheel shimmy is crucial for the automotive industry. To accurately describe the shimmy phenomenon and eliminate it, a new seven-degree-of-freedom (7DOF) dynamic model that includes the steering system, suspension, and electric wheels is developed. By Lagrange’s theorem, the shimmy dynamics equations are derived, resulting in shimmy control state equations. Compared with other shimmy control state equations, these equations consider unknown sensor measurement errors and nonlinear terms. A homogeneous domination-based observer is constructed, which includes the unknown sensor measurement errors. Then, a homogeneous domination-based output feedback controller is designed for vehicle shimmy control. This controller has strong robustness and fast convergence. Via the Lyapunov method, we prove that the designed controller can stabilize the shimmy system asymptotically. Finally, numerical simulations and co-simulations were conducted. By comparing the response time, convergence speed, and overshoot with the SMC, the homogeneous domination-based controller demonstrates superior control performance under specific conditions.