Research On Control Strategy Of Magnetorheological Semi-Active Seat Suspension System For Both Shock And Vibration Mitigation

The impact caused by the detonation of landmines and improvised explosive devices may directly lead to spine fracture and injury of seated occupants on special vehicles.The vibration transmitted from the uneven road surface is another important factor affecting ride comfort/health,on the other hand.In order to solve this problem,firstly,a feedforward damping force tracking approach using a basic resistor-capacitor(RC)operator-based hysteresis model is presented,simulated and experimental researched,realizing to high-efficiently output desired damping force of the controller from the employed magnetorheological energy absorber(MREA).Secondly,a control algorithm for shock mitigation system based on MREA under drop-induced excitation is proposed,simulated and experimentally investigated,with the objective of “soft landing”(i.e.,the final velocity of the payload exactly reduces to zero when consuming the total piston stroke of the MREA).Finally,aiming at minimizing the injury to spine and “discomfort” due to the shock and vibration from the terrain or blast,a MREA-based semi-active seat suspension system for both shock and vibration mitigation is proposed and investigated in this article.The proposed MR semi-active seat suspension system consists of a coil spring supporting the seat and the occupant,a MREA and a fail-safe EA rod.The dynamic model of the MR semi-active seat suspension system with a 4-degree-of-freedom lumpedparameter model for seated occupant is established.A concept of integrated hybrid controller combining strategies for shock and vibration control is proposed and designed.The hybrid controller employs the skyhook control strategy to achieve vibration control and the “soft-landing” control strategy to achieve shock control,and it switches between the two control strategies according to the system dynamic states.Based on the real-time velocity of the seat,the motion process of the “vehicle-seat-human” system can be prejudged,and the critical point for switching the two control strategies can be determined.Sequentially,both ride comfort(i.e.,vibration control)and vertical safety(i.e.,shock control)of the MR semi-active seat suspension system are analyzed and evaluated under different excitations.