Study On Control Of Energy-regenerative Active Suspension Based On Differential Geometry Method

Suspension has the function of alleviating the road impact and improving the ride comfort of the vehicle.Active suspension adjusts the performance of the suspension by changing its nominal stiffness and damping,and improves its ability to suppress vibration.The energy regenerator can recover the vibration energy of the suspension.The combination of the two can improve the ride comfort of the vehicle and reduce the energy consumed by suspension control.A vehicle virtual prototype simulation platform including energy regenerative suspension system was established.Based on the consideration of spatial and temporal correlation,the white noise method is used to establish a double-rut four-wheel road random excitation timedomain model,and the series elliptical cam method is used to construct its equivalent road model as the excitation input of the vehicle model,and introduces the vehicle ride comfort evaluation method and the calculation of the evaluation index,which used as an evaluation standard of vehicle simulation results.Secondly,the vibration nonlinear model of the vehicle with seven-degrees-of-freedom is established by the concentrated mass method,which includes the theoretical model of the energy regenerator,and considers the nonlinearity of the suspension stiffness and damping.Formulate and verify the control strategy of energy regenerative active suspension.Based on the differential geometry accurate feedback linearization theory,the input and output of the nonlinear model of the vehicle are decoupled,and a linearized model with independent input and output is obtained.Based on the result of the optimal poles configuration of the linearized system,the active suspension control strategy is designed;and based on the suspension motion state and active control requirements,the energy recovery control strategy is designed.Finally,the two together constituted the energy regenerative active suspension control strategy.In the vehicle virtual simulation platform,it is verified that the differential geometry method has better suspension control performance,and the energy regenerative active suspension can improve the ride comfort of the vehicle and reduce the energy consumption of active control.Establish a controller hardware-in-the-loop test platform.An electronic control unit(ECU)was designed to control the regenerative active suspension,and a software-in-loop test platform for the active suspension control strategy was built on the real-time target machine to verify the effectiveness of the C code,which generated by the controller model and used in the ECU.Through the connection between the real-time target machine and the ECU,a hardware-in-loop test platform of the regenerative active suspension was built,which verified that the designed ECU could effectively control the active suspension and improve the ride comfort of the vehicle.