Roll plane analysis of a hydro-pneumatic suspension with twin-gas-chamber struts

A hydro-pneumatic strut comprising two gas chambers is proposed to realise nearly symmetric vertical stiffness properties in compression and rebound, and progressively hardening roll stiffness. The fundamental properties of the proposed struts are derived in terms of suspension rate and roll stiffness through formulations of strut forces in the roll plane of a vehicle. Dynamic responses are investigated under excitations arising from vehicle-road interactions and a steady centrifugal acceleration. The results demonstrate that the suspension with proposed struts could reduce ride height drift, and improve suspension topping, tyre deflection and roll response characteristics, with negligible influence on vertical and roll ride.