A Hardware-in-the-Loop Approach to Test Rotary Electromagnetic Shock Absorbers

Electromagnetic shock absorbers are mechatronic actuators designed to improve ride comfort and road holding in ground vehicles by introducing variable active and damping forces in the suspension. This feature difficults their testing, as the characterization test bench must adapt to this variable load feature. Moreover there is interest in testing them under realistic use scenarios. In this context, this work focuses on a hardware-in-the-loop implementation on a custom damper test bench to characterize rotary electromagnetic shock absorbers. First, the entire test bench is presented and described. The model of the plant is obtained together with a quarter car model of the target vehicle. Test bench bandwidth and instability issues are discussed. Then, a model following compensation method is proposed and simulated. Finally, the resulting approach is used to control a testbed, where the quarter car model is used to produce a realistic load duty cycle in real time. Experiments highlight the tracking performance of the test rig and its robustness against load variations.