Abstract
A variable geometry active suspension system is considered. Actuation is employed to vary the leverage ratio between spring/damper unit and road wheel assembly. Since actuation is substantially perpendicular to the main suspension unit forces, work is primarily done only against frictional resistances to motion and the systems have inherently low force and energy requirements. Mechanical design, control system design involving proportional/differential elements or neural networks, self-levelling, free vibrations and manoeuvring of the vehicle are discussed. Good control of roll angle and jacking responses are predicted and energy economy is confirmed by these trials. The results reinforce the notion that variable geometry schemes are worthy of further research effort.