车辆电动静液压自供能量式主动悬架工作机理与协调控制研究

Vehicle active suspension gets a good vibration isolation performance, but it consumes a lot of energy.In this study, self-powered active suspension with Electro-Hydrostatic Actuator (EHA) is put forward. According to the regenerative braking principle of direct current motor,energy regeneration and regenerative braking are realized and recovered energy is used to produce an active control force again.The comprehensive performance evaluation system of energy-regenerative suspension is established by using analytic hierarchy process and entropy value method.In addition,the structure of EHA active suspension is simplified and dynamics models of EHA active suspension are built. The coordinated analysis for suspension dynamic performance and energy-regenerative effect is carried out and the parameters of EHA active suspension are optimized by MATLAB tools. To increase the energy reclaiming efficiency of EHA active suspension, super capacitor and battery are adopted simultaneously and lower energy regenerative voltage is pumped by the boost chopper circuit with Pulse-Width Modulation.Through the analysis of energy flow, layered coordination control strategies are employed to switch the different control modes of EHA active suspension,which refer to energy regeneration mode, regenerative braking mode and drive mode. Under the condition of energy balance, EHA active suspension is powered oneself. Because the delays of controller and actuator are larger in high frequency domain,the control effect of active suspension is not very good.As a result, active mode and semi-active mode should be transformed according to the frequency of disturbance. If suspension system vibrates at low frequency, active control is adopted. At high frequency, semi-active control with regenerative braking is adopted. The application of frequency-dependent control strategies, such as robust control, meets this requirement. For EHA active suspension, time delay is an objective reality.Smith predictor compensation strategy is applied to reduce time delay of EHA active suspension. On the basis of bench tests and real vehicle tests for EHA active suspension, an integrated and practical prototype of EHA active suspension is developed.It provides a new approach to solving the contradictions between vibration isolation and energy consumption.

车辆主动悬架在获得良好减振性能的同时，却消耗了大量能量。本研究提出基于EHA（Electro-Hydrostatic Actuator）电动静液压作动器的车辆自供能量式主动悬架结构。在建立馈能悬架综合性能评价体系和EHA主动悬架模型的基础上，对EHA主动悬架的减振性能与馈能效果进行协调性优化；对较低馈能电压进行泵升，采用复合蓄能装置，解决低速时无法充电的问题，提高悬架馈能效率；在对EHA主动悬架能量流动分析的基础上，采用分层协调控制策略，对EHA主动悬架主动模式、馈能模式、半主动模式进行协调切换控制，根据悬架能量平衡条件，实现EHA主动悬架的能量自供给；采用鲁棒控制策略和Smith 预估补偿策略，有效减小控制时滞对EHA主动悬架的影响。在对EHA主动悬架进行台架试验和实车道路试验研究的基础上，研制出集成化、实用化的EHA主动悬架样机，为车辆减振性能与能量消耗之间的矛盾问题解决提供新的途径。

馈能型主动悬架是汽车悬架技术的发展方向。本项目提出了基于 EHA（Electro-Hydrostatic Actuator）电动静液压作动器的车辆自供能量式主动悬架结构。采用层次分析法、熵权法、组合赋权法以及TOPSIS评价方法，建立了EHA主动悬架评价体系，并开展了基于综合评价的EHA主动悬架参数优化。为了提高悬架馈能效率，对较低馈能电压进行泵升，采用超级电容复合蓄能装置，解决低速时无法充电的问题，振动能量回收效率达到40%。设计了悬架能量管理策略，兼顾悬架减振与馈能性能。采用分层协调控制策略，对 EHA 主动悬架主动模式、馈能模式、半主动模式进行协调切换控制，基于悬架能量平衡条件，实现 EHA 主动悬架的能量自供给。采用Smith预估补偿控制策略，开展了EHA 电动静液压自供能量式主动悬架模糊时滞补偿控制，EHA主动悬架的簧载质量加速度下降约30%，轮胎动载荷下降约20%。研制开发了EHA主动悬架控制器和悬架样机，进行了台架试验和实车道路试验。结果表明，EHA主动悬架簧载质量加速度降幅30%左右，低频输入下的悬架馈能功率均值为10 W~35 W，为车辆减振性能与能量消耗之间的矛盾问题解决提供新的途径。