半车悬架系统的结构解耦控制研究

【作者】 张海龙；

【导师】 王恩荣； 闵富红；

【作者基本信息】 南京师范大学 ， 电工理论与新技术， 2013， 硕士

【摘要】 可控悬架系统能够同时提高车辆驾乘舒适度与操控安全性,因而具有出色的综合悬架性能,从上世纪五十年代起,就是国际车辆工程领域的研究热点课题之一。整车悬架系统一般由四组“四分之一”车辆悬架子系统(Quarter-car,简称QC)组成,各悬架子系统间存在强耦合特性,对整车垂直、俯仰和侧倾三种运动的悬架性能有重要的影响,对车辆多组悬架子系统的协调控制迄今尚缺乏行之有效的解决方案。如能将整车悬架系统解耦为四组独立的QC1,就可直接应用成熟的QC控制方案,从而简化整车控制器设计的复杂性和提高控制实时性,理想地解决车辆多组悬架子系统的协调控制难点问题,对推动可控悬架系统尽早在实际车辆中普及应用具有重要的理论和工程意义。本论文对由两组QC组成的半车悬架系统的解耦控制问题进行了深入研究,该系统存在垂直和俯仰两种运动悬架性能。首先,建立并分析了半车被动悬架系统的动力性模型,将其等效变换为包含两组标准QC的动力学方程,由此发现半车前、后两组QC间的耦合关系,即在簧载质量处存在由车辆俯仰角加速度派生出的耦合量,将其定义为耦合阻尼力,并发现如果在非簧载质量处增加一阻尼力将其补偿,就能实现半车悬架系统的完全结构解耦；其次,根据提出的耦合阻尼力概念,提出了一种采用双可控阻尼器的新型QC结构设计方案,除了将传统悬架系统中的被动阻尼器用可控阻尼器代替外,称为簧载可控阻尼器,还在其下控制臂与连杆之间安装另一个可控阻尼器,称为非簧载可控阻尼器,作用就是补偿耦合阻尼力,其输出阻尼力大小由反馈的车身俯仰角加速度计算得到,从而实现半车前、后两组QC的完全结构解耦；进一步地,验证了提出的半车悬架系统结构解耦方法的正确性,考虑车辆载荷变化,对簧载可控阻尼器应用提出的QC滑模控制器,在主动和半主动(簧载可控阻尼器采用磁流变阻尼器)滑模控制方式下,对解耦的半车可控悬架系统的悬架性能进行比较研究,簧载和非簧载两个可控阻尼器分别采用“主动-主动”、“半主动-主动”和“半主动-半主动”三种基本控制方式,得到了“主动-主动”和“半主动-主动”两种控制方式可以有效地提高半车悬架系统的鲁棒控制综合悬架性能的结论,该方法可以进一步推广应用到对整车悬架系统的半主动解耦控制研究中。更多还原

【Abstract】 The controllable suspension system can improve both ride comfort and handling safety, which has become one research focus in the field of vehicle engineering since1950s. The full-car generally consists of four quarter-car suspension systems (QC) with strong coupling characteristics, which yield strong coupling effects on vertical, pitch and roll movement suspension performances. So far, an effective coordinated control method for the full-car with multiple sub-suspension systems has not been proposed. The best idea is to decouple the full-car into four independent QCs1, such that the sophisticated active or semi-active control scheme for QC suspension can be directly employed, and thus simplify the complicated controller synthesis for the full-car suspension and improve the real-time property of control system, which has important theoretical and engineering values for realizing the practical application of controllable suspension.This thesis focuses on the structural decoupling control study of half-car suspension, which has vertical and pitch movements. Firstly, the passive half-car dynamic model is established and transferred into the model involving two similar standard QC dynamic models. It is found that a coupling damping force exists in the sprung mass, and it can be compensated through adding a damping force in the unsprung mass, in which the half-car suspension could be decoupled into two independent QCs. Furthermore, a new QC suspension design with double controllable dampers is proposed on basis of the defined coupling damping force, in which the traditional passive damper is normally replaced by the sprung controllable dampe. Another damper named the unsprung controllable damper is installed between the lower control arm and linkage of vehicle controlled by the pitch angular acceleration, which plays role in compensating the yielded coupling damping force. Thus the suspension structural decoupling of half-car can be conveniently achieved and effectiveness of the proposed structural decoupling method of half-car suspension is verified. Finally, three kinds of control manners i.e., active versus active, semi-active versus active and semi-active versus semi-active, are fully discussed for the sprung and unsprung controllable dampers, respectively. The proposed active and semi-active sliding mode control schemes for the sprung controllable damper in QC are applied for the decoupling half-car suspension robust control due to the uncertainty of vehicle load, and the semi-active control manner chooses the semi-active controllable magneto-rheological damper. As a result, the proposed both active versus active and semi-active versus active control manners could achieve the ideal multi-objective suspension performances for the half-car, and the proposed structural decoupling control method can be further extended to realize coordinated control of full-vehicle suspension system with multiple sub-suspension.更多还原