Research on Energy-Regenerative Performance of Suspension System with Semi-active Control

Background If the vibration energy of traditional vehicle shock absorber is harvested and reused, the vehicle fuel consumption and exhaust emission will be further reduced. Various transducers of energy-regenerative suspension have been proposed. Semi-active control is applied to coordinate the energy-regenerative performance and the vehicle vibration isolation performance. To realize semi-active control, it is important to design appropriate strategies and energy-regenerative circuit for practical use. Method The unidirectional boost-buck converter is introduced. The steady characteristics of the converter are revealed through the establishment of dynamic differential equations in different operation modes, and thus, the theoretical basis for the mode switch strategy of the converter is provided. Then, the direct current controller including a mode decision module and a sliding mode controller is designed, where the sliding mode strategy is designed based on the average models of the converter under continuous conduction mode. The semi-active control force is derived according to sky-hook and ground-hook control. The relations between semi-active control force and the maximum electromagnetic damping force in frequency domain is theoretically analyzed to increase the effective bandwidth of controllable semi-active force. Results and conclusions Simulation results demonstrate that the energy-regenerative suspension with proposed circuit and semi-active control strategy improves the vehicle ride comfort obviously on random excitation road while slightly deteriorates road-holding performance. The energy-regenerative suspension ensures a 20.53 W of energy that charges the battery on D-class road when the vehicle velocity is 60 km/h.