Electromagnetic hybrid active-passive vehicle suspension system

The suspension systems currently in use can be classified as passive, semi-active and active. The passive suspension systems are the most commonly used due to their low price and high reliability. However, this system can not assure the desired performance from a modern suspension system. An important improvement of the suspension performance is achieved by active systems. Nevertheless, they are only used in a very reduced number of automobile models because they are expensive and complex. Another disadvantage of active systems is the relatively high energy consumption. The use of electromagnetic linear actuators is an alternative for the implementation of active suspensions. Moreover, this solution has the advantage of suspension energy recovery. In spite of the materials development, the electromagnetic actuators are still expensive to produce. In this paper a hybrid suspension system is proposed which combines the simplicity of the passive dampers with the performance of an electromagnetic active suspension. With a passive damper, it is possible to keep the performance of the active suspension, but using a smaller electromagnetic actuator.