Optimal Disturbance Rejection with Zero Steady‐State Error for Nonlinear Vehicle Suspension Systems under Persistent Road Disturbances

Abstract

The road disturbance rejection problem for vehicle active suspension involving the nonlinear characteristics is researched in this paper. A continuous-time state space of nonlinear vehicle active suspension is established first, in which the road disturbance is generated from the output of an introduced exosystem based on the ground displacement power spectral density. After that, based on the dynamics of road roughness and the internal model principle, a disturbance compensator with zero steady-state error is designed, which is related to the dynamic characteristics of road disturbance and independent of the control system model. By combining the vehicle active suspension system and the designed road disturbance compensator, an augmented system is obtained without explicit indication of road disturbance. Then by solving a series of decoupled nonlinear two-point-boundaryvalue problem and employing an iterative computing algorithm, an approximation optimal road disturbance rejection controller is obtained. Finally, the simulation results illustrate that the proposed approximation optimal road disturbance rejection controller can reduce the values of sprung mass acceleration, tire deflection, suspension deflection, and energy consumption and compensate the nonlinear behaviors of vehicle active suspension effectively.

Design and Implementation of H∞ Miscellaneous Information Feedback Control for Vehicle Suspension System

“…A vehicle's suspension is an important vibrationisolating part. It effectively isolates the body from vibrations caused by the road surface to improve the ride comfort [1,2], and it is important for the stability of a vehicle [3,4]. erefore, advanced vehicle suspension systems constitute an important research subject.…”

“…Since an active suspension can generate a preset control force, it can achieve an ideal control effect. An active controller directly determines the vibration-absorption performance of an active suspension system; thus, it has received much attention [1][2][3][4][5][6][7][8][9][10][11][12][13].…”