ABSTRACT

This paper proposes a fault-tolerant controller for active suspension to improve the bounce and pitch performance of a half-car system. In order to guarantee both the transient and steady-state control objectives, the prescribed performance control (PPC) method is applied to regulate the convergence rate, overshoot and tracking error of the closed-loop (CL) system. The system parametric uncertainties including sprung mass, sprung pitch inertia, suspension stiffness and damping coefficient, and axle distances are considered. The dynamics of three types of frequently encountered actuator faults are elaborated. Unlike most of the existing studies that use the adaptive method or neural network (NN) to estimate the uncertain parameters, this paper proposes a novel approximation-free method to deal with the uncertainties. The stability of the CL system is rigorously proved, and the suspension performance is examined with respect to physical constraints. In the numerical simulation, two kinds of imperfect actuators with hybrid nonlinear characteristic are employed to verify the effectiveness of the proposed controller. Simulation results show that the proposed controller can effectively suppress the bounce and pitch motions for the sprung mass and is robust to system uncertainties and actuator faults.

摘要

本文提出了一种主动悬架的容错控制器，以改善半车系统的弹跳和俯仰性能。为了同时保证瞬态和稳态控制目标，采用规定的性能控制（PPC）方法来调节闭环（CL）系统的收敛速度，过冲和跟踪误差。系统参数不确定性包括弹簧质量，弹簧螺距惯性，悬架刚度和阻尼系数以及轴距。详细阐述了三种常见执行器故障的动力学。与大多数使用自适应方法或神经网络（NN）估计不确定性参数的现有研究不同，本文提出了一种新颖的无近似方法来处理不确定性。严格证明了CL系统的稳定性，并针对物理约束条件检查了悬架性能。在数值模拟中，采用两种具有混合非线性特性的不完善执行器来验证所提出控制器的有效性。仿真结果表明，所提出的控制器能够有效抑制簧上质量的弹跳和俯仰运动，对系统不确定性和执行器故障具有鲁棒性。