A multiobjective H∞ control strategy for energy harvesting while damping for regenerative vehicle suspension systems

A significant amount of energy induced by road unevenness and vehicle roll and pitch motions is usually dissipated by conventional shock absorbers as they dampen their vertical motions. In this paper, a novel multiobjective H_∞ control design method is proposed. Besides the usual control objectives for performance, it includes the amount of energy to be harvested as a further conflicting objective and allows the designer to directly trade-off among them. An electromechanical regenerative vehicle suspension system is considered where the viscous damper is replaced by a linear electrical motor which is actively governed. It is shown that the proposed control law is able to achieve remarkable improvements on the amount of harvested energy with respect to passive or semipassive control strategies while maintaining the other objectives at good levels. Simulative studies undertaken via CarSim that confirm the potentiality and flexibility of the proposed control design strategy are also reported.