A Generalized Model to Describe Electromagnetic Shock Absorbers

The development of chassis technologies has pushed significant focus towards electrification for enhanced vehicle efficiency, flexibility, safety, and performance. In this context, the suspension represents a key system, as it strongly influences both vehicle dynamics and comfort. The trend is to replace the usual hydraulic damper with mechatronic actuators. Rotary electromagnetic shock absorbers are among these solutions, featuring a rotary electric machine and a proper rotary-to-linear transmission stage. Far from being ideal force sources, these actuators may introduce inertial, compliance, and friction phenomena to the suspension. This paper proposes a generalized equivalent model to reproduce the mechanical behavior of electromagnetic shock absorbers. The formulation of this tool helps compare different shock absorber technologies in terms of their dynamic response. Furthermore, it can be used to synthesize control strategies that account for intrinsic limitations of chassis actuators.