Research On Active Seat Suspension Of Commercial Vehicle With Energy Recovery

Seat suspension plays a role in reducing the driver’s vibration and improving ride comfort,which is widely used in the commercial vehicles.The active seat suspension uses the actuator to output controlled force to the seat through consuming external power supply,which greatly improves ride comfort compared to the passive seat suspension.In order to solve the problem of high energy consumption of active seat suspension,an energy-feedback active seat suspension with energy recovery function is designed in this paper,when its dynamic model and controller are established.Besides,prototype of the energy-feedback active seat suspension is manufactured for bench test.Through bench test,the ride comfort and economy of the seat suspension are analyzed.(1)The dynamic model of active seat suspension with active actuating system is established based on the four-degree-of-freedom dynamic model of commercial vehicle.By analyzing the transmissibility of seat suspension,the stiffness is matched and the damping coefficient is optimized.The friction model of the seat suspension is established and the friction force of the system is measured and identified by the friction experiment of the whole seat.Besides,the mathematical model of DC motor actuator and fork scissors drive mechanism is established.(2)The control algorithm and hardware circuit structure of the active seat suspension are designed and the simulation is completed.In terms of algorithmic control,the active control algorithm model of seat suspension is established by use of drive status of DC motor actuator based on LQR algorithms and H-infinity algorithms.The energy recovery control algorithm model is established by use of energy-feedback status of DC motor actuator based on Skyhook damping control theory.The mode of controller is chosen between the active control mode and energy recovery mode according to the feedback signal.In terms of hardware control,the current hysteresis control model of DC motor actuator is established,and the topology structure of the hardware circuit is designed which satisfy the dual mode switching control.Then the improvement of ride comfort and economy of the integrated control strategy is verified by system control simulation.(3)The active seat suspension prototype is designed and manufactured,and software in loop(SIL)simulation is carried out.Based on the energy-feedback active seat suspension designed in this paper,the mechanical structure of the prototype is designed and manufactured,the hardware of the circuit is built,and the selection of sensors and controller are completed.The control algorithm is written into C language through embedded code generator,and the actual controller is simulated to control the digital model.The comparison and analysis between the SIL simulation and pure digital simulation are carried out to verify the effectiveness of the hardware implementation of the control algorithm.