Semi-active control of a new quasi-zero stiffness air suspension for commercial vehicles based on H2H∞ state feedback

Abstract

To further improve the comprehensive vibration isolation performance of commercial vehicles equipped with traditional passive air suspensions under complex driving conditions, this paper proposes a damping control method based on a new configuration of quasi-zero stiffness air suspension . First, the nonlinear model of quasi-zero stiffness air suspension is established by combining gas thermodynamics and suspension dynamics theories. The semi-active control model of a quarter vehicle quasi-zero stiffness air suspension system is generalized to a linear system considering the uncertainty of stiffness parameter based on the Taylor series expansion. Then, the H2 norm of the sprung mass acceleration is adopted as the control output performance index, while the suspension dynamic deflection constraint and the tire dynamic load constraint are taken as the H ∞ performance constraint output index. Based on Lyapunov stability theory, the H2 H ∞ state feedback control law is designed, and the control law design problem is transformed into a convex optimization problem with linear matrix inequalities. Finally, co-simulation and hardware-in-the-loop test results demonstrate that the proposed new semi-active quasi-zero stiffness air suspension structure and H2 H ∞ robust control method are effective in substantially improving the multi-objective comprehensive performance of commercial vehicles under different driving conditions.