Abstract: A method of on-demand energy delivery to an active suspension system is disclosed. The suspension system includes an actuator body, a hydraulic pump, an electric motor, a plurality of sensors, an energy storage facility, and a controller. The method includes disposing an active suspension system in a vehicle between a wheel mount and a vehicle body, detecting a wheel event requiring control of the active suspension; and sourcing energy from the energy storage facility and delivering it to the electric motor in response to the wheel event.

Abstract: A variable ride height vehicle suspension system in which the energy input is from ground impact includes a telescopic hydropneumatic strut with a liquid chamber separated from a gas chamber by a free piston. A reservoir external of the strut is connected to one of the chambers via a valve arrangement also external of the chambers. The valve arrangement is selectively operable to permit unidirectional fluid flow in one or the other direction between the reservoir and the strut chamber to which it is connected, the flow direction being selected to enable lengthening or shortening of the strut in response to pressure oscillations in the gas chamber.