Load levelling control for an hydro-pneumatic suspension of a tractor cabin: Modelling, identification and control

This paper deals with the load levelling control of a tractor cabin equipped with an hydro-pneumatic suspension, controlled with on-off actuators. A model-based approach for the controller design is proposed. A dynamic physical model of the hydro-pneumatic suspension is developed and identified through a grey-box approach and a linear continuous controller is then designed, where actuation delays and model uncertainties are considered. The continuous-time controller requests are then converted into actual on-off switching valves commands through a duty-cycle modulation. Experimental results validate the overall approach showing effective closed-loop performances.