Abstract: In order to realize low cost and multi-pose for a different fibers sorting robot, the robot structure and flexible was analyzed. The robot selected 5-DOF structure (PRRRP). This paper established the robot's D-H kinematics parameter table and worked out inverse kinematics solution of the position vector corresponding joint variables. The boundary constraints of joint variables were determined by graphic method. The concept of flexibility was defined. The evaluation function of flexible degree was established on the half-section of cotton pile. The joint variables parameters with most flexible points were obtained by optimization calculation. At last, this paper pointed out that the design criterion of the flexible to achieve multi-pose movement was a design method with low cost, easy to control on the low DOF robot.

Key words: robot, foexibility, D-H parameter table, service ball