Study on kinematic optimization of a combined parallel-serial manipulator

This research develops the robot manipulator combined a parallel manipulator and wrist manipulator. The robot has a parallel manipulator with three linear actuators and a central axis for positional motions, i. e., x, y, and z and a wrist manipulator with two rotary actuators for rotational motions, i.e., yaw and pitch. The proposed parallel-serial typed manipulator which has between high stiffness of parallel manipulator and high flexibility of wrist manipulator is applied to in machining work such as cutting, milling, grilling, etc. This paper introduces the parallel-wrist typed robot as a machining center and an assembly robot for the complex shape. In order to achieve the optimal design, we define four parameters such as the radius of a base and a platform, the initial length of linear actuator, and the stroke of linear actuator. To determine the parameters, investigation is done i.e., kinematics, available workspace, and dexterity analysis. In results, we show four optimal design parameters of parallel manipulator meet a desired workspace including orientational work of wrist manipulator.