基于状态反馈和预瞄前馈的智能车半主动悬架控制

Semi-active Suspension Control for Intelligent Vehicles Based on State Feedback and Preview Feedforward

为提高智能车辆的半主动悬架综合控制性能,提出一种基于状态反馈和预瞄前馈的半主动悬架控制方法。首先,以8轮车为研究对象建立11自由度半主动悬架模型,设计LQR状态反馈控制器。然后,为解决状态反馈控制抗路面干扰能力弱和基于固定时序延迟的预瞄反馈控制适用性差的问题,提出一种基于状态反馈和预瞄前馈的控制器:建立车轮运动规划模型和路面预瞄模型,计算出悬架控制系统所需的车轮规划轨迹点序号和控制延迟响应时间;以路面激励和垂向加速度为输入、以前馈阻尼力为输出,设计基于类模糊的预瞄前馈控制器,并与LQR反馈控制器一并构成所提控制器。最后,基于MATLAB/Simulink和Trucksim联合仿真平台,进行匀速转向工况、变速直线工况、变速转向工况和匀速直线工况下的试验验证。结果表明,在垂向加速度、俯仰角加速度、侧倾角加速度均方根值方面,与被动悬架相比,所提控制方法在4种工况下至少降低了23.52%、13.59%、19.35%;与基于固定时序延迟的预瞄反馈控制相比,所提控制方法在前3种工况下至少降低了14.04%、8.09%、13.79%;与基于状态反馈的控制方法相比,所提控制方法在第4种工况下降低了13.20%、4.96%、4.12%。所提悬架控制方法能够在多种工况下有效改善车辆的平顺性。

In order to improve the comprehensive control performance of intelligent vehicle semi-active suspension,a semi-active suspension control method based on state feedback and preview feedforward is proposed.Firstly,an 11-DOF semi-active suspension model is established with an 8-wheeler as the research object,and an LQR state feedback controller is designed.Then,in order to solve the problems of weak road disturbance resistance ability of the state feedback control and poor applicability of preview feedback control based on fixed timing delay,a kind of controller based on state feedback and preview feedforward is proposed,establishing the wheel movement planning model and road preview model to calculate the wheel planning trajectory point number of the suspension control system and the control delay response time.Taking road excitation and vertical acceleration as input and feedforward damping force as output,a fuzzy-like preview feedforward controller is designed,and together with the LQR feedback controller to form the proposed controller.Finally,based on the co-simulation platform of MATLAB/Simulink and Trucksim,the experiments are carried out under the conditions of constant speed steering,variable speed straight line,variable speed steering and constant speed straight line.The results show that the root mean square value of vertical acceleration,pitch angle acceleration and roll angle acceleration is at least reduced by 23.52%,13.59%and 19.35%compared with the passive suspension under four working conditions.Compared with the pre-view feedback control based on fixed time delay,the proposed control method reduces at least 14.04%,8.09%and 13.79%under the first three working conditions.Compared with the control method based on state feedback,the proposed control method reduces by 13.20%,4.96%and 4.12%under the fourth working conditions.The proposed suspension control method can effectively improve vehicle ride comfort under various working conditions.