摘 要

本文利用了线性二次最优控制策略对汽车的半主动悬架系统进行仿真控制。通常车辆的乘坐舒适性、平顺性以及操纵稳定性对汽车及乘客影响很大。为了提高这些方面的性能，会考虑簧载质量加速度等参数。本设计中液压减震器被磁流变阻尼器取代同时设置了一个控制器，用于控制开发阻尼悬架系统的力。所得结果对于汽车乘坐舒适性具有指导意义。

论文主要建立了单质量和双质量系统车辆模型，建立状态空间方程。选择合适的控制目标之后，利用LQR控制策略，得到最优解。最后使用Matlab软件和Simulink软件进行计算以及模拟仿真。

研究结果表明：双质量系统更能反映实际情况，通过半主动和被动悬架的比较，得出其较被动悬架在汽车平顺性方面有很大的优势，LQR的控制策略于半主动悬架的应用和模拟方面具有很好适用普及性。

本文的特色：将单质量系统和双质量系统比较，将被动悬架和LQR控制的半主动悬架相比较，时域和频域共同分析等特色。

关键词：半主动悬架；LQR；仿真；可调阻尼减震器

Abstract

This paper mainly focuses on the design of the linear two regulator (LQR) for the automotive semi active suspension system. The pros and cons of the vehicle suspension system is usually according to whether it can provide good running safety and ride comfort to judge, in order to improve the comfort of the vehicle and take the safety and reliability, need to consider the four parameters: the acceleration of the sprung mass, spring mass displacement, the displacement of the spring and suspended frame deflection. Semi active suspension is adopted in the design of the suspension system. In this design, the hydraulic shock absorber is replaced by the MR damper, which is used to control the development of the damping suspension system. Semi active suspension controller reduces the body acceleration and the displacement of the body and tires, the results of the improved passenger comfort has a guiding significance.

In this paper, the state space equation of the vehicle model with single mass and double mass system is established, and the linear quadratic optimal control strategy is used to select the controller's performance parameters, and the optimal control law is determined. Using Matlab / Simulink software to simulate the LQR control strategy.

The research results show that the double quality system can reflect the actual situation, through the comparison of semi active and passive suspension, it is concluded that it has a great advantage in the vehicle ride comfort. Linear quadratic control strategy has more prominent features than other strategies in some aspects in some aspects.

The characteristics of this paper: the single quality system and double quality system comparison, the passive suspension and LQR control of semi active suspension phase comparison, time domain and frequency domain common analysis and other characteristics.

Key Words:semi-active suspension ；LQR,simulation；adjustable damping shock absorber

目录

第1章 绪论 .................................................................1

1.1 悬架简介...............................................................1

1.1.1 悬架功用和组成.....................................................1

1.1.2 悬架系统的自然振动频率.............................................2

1.1.3 悬架的分类.........................................................3

1.2 半主动悬架的可调减振环节...............................................3

1.2.1可调阻尼器.........................................................4

1.2.1.1有极可调阻尼器..................................................4

1.2.1.2无极可调阻尼器..................................................4

1.2.2可控弹性元件.......................................................5

1.3 控制策略简介...........................................................5

1.4汽车平顺性和操纵稳定性介绍..............................................7

1.5论文思路过程简介.......................................................7第2章 汽车半主动悬架建模....................................................9

2.1汽车模型的简化..........................................................9

2.2 单质量系统建模........................................................10

2.3四分之一车辆半主动悬架建模.............................................12第3章 LQR控制器设计........................................................15

3.1 控制指标的建立........................................................15

3.2 最优控制律的设计......................................................16

3.3 关于Q，R，N的选择原则................................................17

第4章 模型仿真和结果分析...................................................18

4.1 单质量模型的仿真......................................................18

4.1 双质量模型的仿真......................................................21

4.3 频域分析..............................................................26

4.4 仿真分析..............................................................30

第5章 结论.................................................................32

参考文献...................................................................34

附录.......................................................................37

附录A 单质量系统编程.....................................................37

附录B半主动悬架编程.....................................................37

附录C被动悬架编程.......................................................38

附录D频率响应部分编程...................................................39