A New Kind of Measuring Tooling and Closed-loop Control for Gough-Stewart Parallel Robot

Due to the lack of reliable way to obtain its position/speed information, the closed-loop control in Gough-Stewart parallel robot’s workspace cannot be realized, therefore the application of Gough-Stewart parallel robot is restricted. In this paper, a peg-hole relative position and orientation measuring tooling for Gough Stewart parallel robot is designed. The kinematics model of the peg-hole relative position and orientation measuring tooling which establishes the relative pose relations between the readings of the measuring tooling and the through-holes is established. The relationship between the readings of the measuring tooling and the pose of the top plate is then obtained, based on which the velocity and acceleration of the top plate can be obtained and the closed-loop control of peg-in-hole assembly Gough-Stewart parallel robot in its workspace may be realized. The sliding mode controller and the super twisting controller is established for control this robot. Results of simulation can prove the validity of the dynamic model and the stability of two controllers. By compare this two controllers we can obtain the conclusion that the super twisting controller is better than the sliding mode controller especially used in peg in hole operations. The application range of Gough-Stewart parallel robot could be widen by this work.