Modeling, simulation, and control of a hydraulic Stewart platform

This paper describes the modeling, simulation, and control of an inverted, ceiling-mounted Stewart platform, designed to be a one-person motion simulator. The dynamic equations of the Stewart platform are derived using the virtual work principle. It is shown by simulations that the leg dynamics can be neglected. A model of the electrohydraulic actuator is derived and then verified using experimental data. A linkspace pressure-feedback controller is proposed for high performance with good stability robustness. With the above controller, the small-motion position bandwidth of the platform can reach 9 Hz along the vertical axis for a payload of about 140 kg.