Control Algorithm Study For A Pneumatic Energy Regenerative Suspension

The active suspension technology has become one of the research hot points.It can adapt to the change of the road surface,enhance the handling stability and improve the comfort performances.However,the practical applications of the active suspension were limited due to its high energy consumption.As one of the potentional solutions,the energy-regenerative system could recollect the vibration energy so as to decrease the energy requirement for the suspension control.Therefore,a new type of pneumatic energy-regenerative active suspension was proposed in this paper.It can not only recover the vibration energy but also realize the active control of suspension systems.The pneumatic energy-regenerative suspension used a ball screw with an off-center mounted nut.This mechanism acted as the transmission mechanism,and a compressed cylinder was connected to it acting as an actuator.The mathematic model of the pneumatic energy-regenerative suspension was established after analyzing the structure and working principle.Then the dynamic analysis on the actuator was carried out.The mathematics model and its dyamcis analysis constructed the foundations of the control algorithm.For the control algorithm study,we used the LQG,the sliding mode and an improved LQG control based on the analytic hierarchy process respectively.In the Matlab/Simulink software,three models were built and simulated.Four indexes were chosen to evaluate the suspension performances.Besides the three traditional indexs,e.g.the body acceleration,the suspension working space and the dynamcs tire displacement,the energy-regenerative efficiency was added as a new one.The simulation results showed that the sliding mode control algorithm had obviously delay problems.The improved LQG control algorithm had better control effects on the vehicle comfort and suspension working space.