为了回收车辆悬架系统在行驶过程中产生的振动能量,提出了一种液电式馈能半主动悬架(hydraulic-electrical energy regenerative semi-active suspension,HERSS)系统方案,并深入研究了HERSS半主动控制特性及馈能特性.根据HERSS系统原理,明确了其独特的单行程可控特点,推导了HERSS四分之一悬架系统方程,设计了线性最优LQG (linear quadratic Gaussian)控制器,利用MATLAB/Simulink搭建了基于LQG控制的HERSS仿真模型,通过仿真试验对比分析了HERSS、被动悬架、传统半主动悬架的性能差异.最后,进行了HERSS的馈能特性台架试验.研究结果表明:针对簧载质量加速度、悬架动行程、车轮动位移3个指标而言,由于HERSS仅伸张行程阻尼力可调的特点,其综合性能介于被动悬架、传统半主动悬架之间.针对馈能特性,当控制电流达到30A时,HERSS回收能量功率最高为51.94 W,对应的能量回收效率为12.86％,并且试验数据整体呈现出HERSS回收到的振动能量及能量回收效率随着控制电流的升高而增大的规律.其他悬架形式无法回收振动能量,因此,HERSS在馈能特性指标上具有明显优势.综上所述,HERSS能够满足汽车对半主动悬架系统的功能要求,并具有能量回收功能,在新能源汽车领域具有一定应用价值.该文研究成果可为液电式馈能悬架的实际应用提供参考.%To recycle the vibration energy of vehicles over rough roads,a vehicular hydraulic-electrical energy regenerative semi-active suspension (HERSS) was designed in this work.Simulations and bench tests were performed with focus on its suspension performance and energy harvesting characteristic,respectively.The key component in the HERSS was the hydraulic-electrical energy regenerative absorber (HERA),and the HERA was composed of a hydraulic cylinder,three check valves,two accumulators,a hydraulic motor,a generator,and hydraulic lines.Firstly,on the basis of the HERSS principle,the system configuration and working principle were described.The test bench was constructed according to the HERA theory,and the speed characteristic curve of HERA was obtained through bench test.Secondly,the two degrees of freedom HERSS dynamic model was constructed.From the model equation,damping force of HERSS contained viscous damping force and motor control force.The viscous force was the inherent damping characteristic of HERSS caused by throttle resistance of check valves,frictional resistance of pipe lines,throttle resistance of hydraulic motor.The motor control force can be adjusted according to the control strategy.According to the HERSS principle,the motor control force can be adjusted in the extension stroke only and as such,the control strategy can be used to identify suspension motion state.When the suspension in the compression stroke,the motor control force could not affect the HERSS,but in the extension stroke,the motor control force was variable according to the control strategy.In order to evaluate the HERSS performance,sprung mass acceleration,suspension deflection and tire dynamical displacement were chosen as assessing index.Then,the Linear Quadratic Gaussian (LQG) controller was designed for HERSS.In the processing of LQG design,the weighting coefficient of HERSS performance index was determined by Analytic Hierarchy Process (AHP).Thirdly,the performance of HERSS with LQG control was compared with passive suspension (PS),traditional semi-active suspension (TSS) with LQG control through simulation tests.The frequency results indicated that:(i) in the resonance frequency of sprung mass,the amplitude of suspension index parameters ranked in a descend order,PS,HERSS and TSS.The results reflected that LQG strategy could reduce the sprung mass vibration effectively.And because HERSS could not change its damping force during compression stroke,its effect of vibration elimination was better than the PS,but worse than the TSS;(ii) in the resonance frequency of unsprung mass,the amplitudes of sprung mass acceleration calculated by three models were similar.The amplitudes of suspension deflection were too small to display as frequency of peak.And the amplitudes of tire dynamical displacement ranked in a descend order,PS,HERSS,TSS.In general,in the resonance frequency of unsprung mass,the differences of amplitude of suspension index parameters were very small;(iii) in the transition frequency band,which was between the resonance frequency of sprung mass and the resonance frequency of unsprung mass,the amplitudes of sprung mass acceleration and tire dynamical displacement ranked in a descend order,TSS,HERSS,PS.The differences of amplitudes of suspension deflection were small.Lastly,the absorber dynamical displacement data was collected through road test.The acquisition data used in energy harvesting bench test as input signal.The bench test results showed that the HERSS was feasible,and the harvested energy power and energy harvesting efficiency of HERA were increasing with the rise of the control current.
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