The Electromechanical Low-Power Active Suspension: Modeling, Control, and Prototype Testing

The high energy consumption of market-ready active suspension systems is the limiting factor in the competition with semi-active devices. The variable geometry active suspension is an alternative with a significantly lower power consumption. However, previous designs suffer from packaging problems, nonlinear stiffness characteristics, and failsafe issues. This paper discusses the feasibility of a recently presented, new design, variable geometry actuator, which has a fixed spring and constant stiffness. An actuator model is derived that includes the electric motor and friction characteristics. Using this model, a cascaded controller is developed and the steady-state and dynamic properties are evaluated. The simulation results are validated with prototype tests. The results show a good correspondence between simulations and measurements. Furthermore, a 10 Hz bandwidth can be easily obtained. It is concluded that the electromechanical low-power active suspension design is feasible and that the model gives a fairly accurate representation of both the steady-state and dynamic characteristics of the prototype.