Increasing Energy Harvesting in Regenerative Suspension Systems via Multiobjective ℋ∞ Control

A novel multiobjective ℋ∞ state-feedback control design methodology is proposed which includes, besides the usual control objectives on ride comfort, road handling and suspension stroke, the amount of energy to be harvested as a further conflicting objective and allows the designer to directly trade-off among them depending on the application. 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 remarkably improvements on the amount of harvested energy with respect to passive or semi-passive control strategies while maintaining the other objectives at acceptable levels. It is also shown how the state-feedback design can be converted into a 2DOF dynamic output feedback control strategy by using a suitable state observer. Simulative studies undertaken via Simulink are finally reported that confirm the potentiality and flexibility of the proposed control design strategy.