Analysis of 6-DOF motion with PI controller in electrohydraulic stewart platform

Abstract

A Stewart platform that is a 6-DOF parallel manipulator with a moveable frame for three linear and three angular motions has been designed with electrohydraulic actuation for achieving maneuverability of heavy load. A popular application is the motion simulator for an aircraft or a ship that could be used for training by generating specific motions within the confine of a laboratory. The main contribution of this work is the design and realization of a high-precision simulator with low-cost proportional valves using a simple PI controller for achieving basic motions. A pose-feedback controller has been conceived for the system constructed on the basis of the feedback of the leg lengths and a linearized inverse kinematic model about the neutral position. A number of real-time experiments have shown the design to be quite satisfactory.