Levelling Control of an Electro-pneumatic Stabilized Platform Driven by Pneumatic Muscles

An electro-pneumatic stabilized platform driven by pneumatic muscles (ESPDPM) was proposed to realize leveling of important devices for ship-borne application. An adaptive robust leveling control strategy based on the MIMO terminal plant dynamics was proposed to remain level with the horizon at all times for the electro-pneumatic stabilized platform system subject to various vibration or environmental disturbances. The resulting controller can effectively compensate various parameter uncertainties due to unknown parameters in the terminal plat dynamics through parameter adaptation, and simultaneously handle large amount of uncertain nonlinearities due to neglected hard-to-model nonlinearities and environmental disturbances such as time-varying friction forces of pneumatic muscles, modeling error from contraction force of pneumatic muscles, pressure differential and flow rate equations, and observation error of disturbance posture etc.. The simulation results demonstrated a maximum leveling error of 0.45d for the electro-pneumatic stabilized platform using the proposed leveling controller.