Simulation Study on Vehicle Road Performance with Hydraulic Electromagnetic Energy-Regenerative Shock Absorber

This paper presents a novel application of hydraulic electromagnetic energy-regenerative shock absorber (HESA) into commercial vehicle suspension system and vehicle road performance are simulated by the evaluating indexes (e.g. root-mean-square values of vertical acceleration of sprung mass, dynamic tire-ground contact force, suspension deflection and harvested power; maximum values of pitch angle and roll angle). Firstly, the configuration and working principle of HESA are introduced. Then, the damping characteristics of HESA and the seven-degrees-of-freedom vehicle dynamics were modeled respectively before deriving the dynamic characteristics of a vehicle equipped with HESA. The control current is fixed at 7A to match the similar damping effect of traditional damper on the basis of energy conversion method of nonlinear shock absorber. Compared with the vehicle equipped with conventional shock absorber under the same excitation conditions of random road and vehicle speed, vehicle dynamics response and energy-regenerative potential of HESA suspension system are analyzed. Judging with the first three main evaluating indexes, the numerical differences between HESA equipped vehicle and conventional one in the vertical acceleration of sprung mass is within 9.2%, the dynamic tire-ground contact force is within 2.2%, and the suspension deflection is within 6.1%. The handling stability of fixed current control and failure mode of HESA is comparatively analyzed. Moreover, when offering reliable damping force for vehicle suspension system, HESA could regenerate power from 41.72 to 339.88 W (RMS) with vehicle speed ranging from 30 to 70 km/h on Class B and Class C random road.