Phenomenological Model of a Magneto-rheological Damper for Semi-active Suspension Control Design and Simulation

Active and Semi-active Suspensions have been widely studied over the last 20 years, with hundreds of papers published. Most of the published results focus on the main-loop design, i.e., on the computation of the desired control force, as a function of vehicle states and the road disturbance. It is commonly assumed that the commanded force will be produced accurately, so simulations of these main-loop designs were frequently done without considering actuator dynamics, or with highly simplified sub-loop dynamics. In reality, actuator dynamics can be quite complicated, and interaction between the actuator and the vehicle suspension cannot be ignored. This is especially true for magneto-rheological dampers, which are semi-active force actuators that remain some force dependency with damper velocity and have hysteretic behavior when damper movement change the direction. This work presents a methodology to get a phenomenological model of magneto-rheological dampers from experimental data, using a Sequential Quadratic Programming (SQP) algorithm. This phenomenological model can be used in semi-active suspension control design and simulation.