Self-powered active suspension

In recent years there has been growing interest in alternative energy source that could satisfy the large demand for energy and guarantees a low environmental impact at the same time. In the automotive field, in particular, many devices to harvest energy has been developed such as regenerative braking systems or regenerative suspension. In this thesis a self-powered active suspension system is proposed in which a single actuator realizes active control of the chassis and regeneration of vibrational energy excited by the uneven road. The actuator is essentially a linear tubular permanent magnet motor that exploit Eddy currents, generated in the stator coils, by the relative motion between the magnets and the coil itself. The actuator is connected to a condenser through controllable relay switches which decide the direction of the current and a variable resistor which decide the amount of the electric current. The latter is proportional to the force provided by the actuator. Thus by controlling the variable resistance it is possible to track the desired force given by a skyhook control law.