车辆电磁直线式自供能混合主动悬架工作机理与协调控制研究

Vehicle active suspension achieves good damping properties, while it consumes a lot of energy. A new kind of self-powered active suspension with electro-magnetic linear hybrid actuator (EMLHA) is proposed to improve the reliability and damping force of active suspension with an electro-magnetic linear actuator, as well as to reduce the suspension cost and demands for the motor rated capacity. Such system consists of EMLHA and variable voltage source system. The EMLHA is composed of an electro-magnetic linear actuator and an adjustable shock absorber with electromagnetic valves. The designed variable voltage source system mainly includes AC-DC synchronous rectifier, bidirectional DC-DC voltage converter and ultra capacitor. The ultra capacitor is used as the electric source to store and release power energy because of some natural advantages such as fast charge and discharge, long life, small size, maintenance-free, easy installation, and so on. When the electro-magnetic linear actuator works as a generator, the induced three-phase AC is transformed into DC through the bridge rectifier. Similarly, when the electro-magnetic linear actuator works as an electric motor, the DC is transformed into the AC through the bridge rectifier again. The DC-DC converter can work in boost and buck modes by means of controlling the power switches. And it overcomes the problem which is that the regenerative suspension doesn’t produce any damping force and the energy isn’t regenerated during low speed motion because of back electro motive voltage being smaller than the power source voltage. As a result, energy regenerative efficiency of the active suspension is improved and bidirectional power flow control is realized. Aiming at the EMLHA active suspension, suspension dynamics models, EMLHA models and control circuit models are separately established. The analyses of the suspension parameter sensitivity are done. By using the multi-objective parameter optimization method, the coordinate optimization for synthetical performance of the EMLHA active suspension is carried out. When the voltage source accepts more energy than it releases, average electric power consumption becomes negative. This is the necessary condition for the proposed self-powered active suspension with EMLHA. Through analyzing the power flow in the EMLHA, the mode switch rules of the EMLHA active suspension are designed. When both actuator output power and electric source power become negative, the electro-magnetic linear actuator acts as a generator, which is regeneration mode. When both actuator output power and electric source power are greater than or equal to zero, the actuator transfers the energy to the suspension from the electric source as active mode. When electric source power is greater than or equal to zero, while actuator output power is less than or equal to zero, the EMLHA accepts energy from the suspension and the electric source. Then，the energy is dissipated in the resistance of the armature and the actuator produces a variable damping force as semi-active mode. The hierarchical coordinated switching controller of the active suspension, which includes inner-loop controller and outer-loop controller, is designed and the coordinated switching control simulations are done. Based on the bench tests and real vehicle tests for the EMLHA active suspension, an integrated and practical prototype of the EMLHA active suspension is developed. It provides a new approach to solving the contradiction between vibration isolation and energy consumption.

车辆主动悬架在获得良好减振性能的同时，却消耗大量能量。将电磁直线作动器与电磁阀可调减振器集成，提出基于EMLHA（electro-magnetic linear hybrid actuator）电磁直线混合作动器的自供能主动悬架结构。在系统精确建模和参数敏感性分析基础上，利用多目标参数优化法对EMLHA悬架减振与馈能进行协调性优化；设计包含AC-DC同步整流器、双向DC-DC电压变换器、超级电容的可变电压源系统，解决低速时馈能电压较小无法充电问题，提高悬架馈能效率，在控制器作用下实现EMLHA悬架充放电流的双向流动；开展基于功率流分析的EMLHA悬架主动、馈能、半主动、容错模式分层协调切换控制；基于悬架能量平衡条件，实现EMLHA悬架能量自供给。在EMLHA悬架台架试验和实车道路试验基础上，研制集成化、实用化的EMLHA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发展的方向。本项目提出了基于EMLHA（electro-magnetic linear hybrid actuator）电磁直线混合作动器的自供能主动悬架结构。在对电磁直线混合作动器数学建模和有限元建模的基础上，进行了悬架作动器参数敏感性分析和多目标粒子群优化；基于不同行车速度与路面等级构成的行驶工况进行了悬架工作模式划分，开展了不同行驶工况下的天地棚阻尼参数协调性优化分析。进行了超级电容储能装置的参数匹配与测试，设计一种包含AC-DC同步整流器、双向DC-DC电压变换器和超级电容的可变电压源系统，在控制器作用下实现EMLHA悬架充放电流的双向流动，解决低速时无法充电的问题，一定的程度上能够提升了车辆动态性能。当直线电磁作动器出现故障时，可实现EMLHA主动悬架的多模式容错控制；设计了EMLHA主动悬架主动模式、馈能模式、半主动模式分层协调切换控制策略；根据悬架能量平衡条件，可实现EMLHA主动悬架的能量自供给。设计开发了EMLHA主动悬架控制系统和样机，进行了台架试验和实车道路试验，验证了控制策略的有效性，悬架的安全性与舒适性得到提高，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。