Kinematics Identification and Control of R-Cube Parallel Robots Only with Revolute Joints

Due to their simplicity in manufacture and high load capacity, the revolute parallel manipulators come to front in the recent years. But the large number of links and passive joints often limit the performance of revolute parallel manipulator in terms of accuracy, therefore, the kinematic parameters of such mechanisms have to be identified by the kinematic identification. R-Cube is a 3-DOF translational parallel manipulator and has decoupled motion in x, y, and z axes, and employs only revolute joints. The structure and kinematics properties of the manipulator are studied in this paper using screw theory. The forward and backward kinematic model is introduced in inverse-implicit form by using invariant geometry theory of screws. In order to realizing the kinematic identification, the vision-based control model is established and the image depth evaluation system for such a manipulator is introduced for the first time. Finally, an inverse-implicit kinematic identification mothod is proposed.