Abstract
This thesis presents a six-DOFs motion measurement device based on Linapod parallel kinematics, which composes of one top platform, one base platform and six link rods having constant length. The top platform is fixed with the main spindle and the base platform is mounted on the work table. The platforms are connected by six link rods with two ball joints at both ends of each link rod. When the work tables of the machine tool move, the platforms are driven by the main spindle or the work table. As a result, the ball bearing sockets on the linear guide way of the top platform are driven by the link rods. By measuring the position of the sockets, the relative position and orientation between the platforms can be derived, which also represent the relationship between the cutting tool and the work piece.