Active Struts With Variable Spring Stiffness and Damping

Controllable active struts that would function as linear actuators with variable spring stiffness and damping have been proposed as components of advanced suspension systems of future wheeled ground vehicles. The contemplated advanced suspension systems would include computer-based control subsystems that would continually adjust the actuator responses to obtain optimal combinations of safety and comfort under operating conditions ranging from low speeds over smooth roads to high speeds over rough, unpaved ground. The proposed struts and suspension systems were originally intended for use in military vehicles, but there could also be a broad commercial market for them in trucks and sport utility vehicles.