General motion planning method for manipulators with no impact

Abstract

Abstract-This paper proposes a general motion planning method for manipulators on the basis of polynomial interpolation. The impact suffered by manipulators during movement can be eliminated by using this method. And this reduces vibration of manipulators largely. In order to overcome the difficulties in realizing the algorithm, a method of quadratic interpolation is proposed. With the method, the computation amount of motion planning is reduced, while the result is still with no impact. The motion planning experiments driving the manipulator's end effector to run a three-dimensional arc are carried out with a self-developed 6-DOF manipulator system. Through the experiments, it is verified that the motion planning method proposed is feasible and has good effects. I. INTRODUCTIONanipulators have already been used very widely in automation in modern times. The structures of traditional industrial manipulators are all very bulky and heavy. And the ratio of the structural weight and the payload is very large. The purpose of this kind of design is to give manipulators sufficient rigidity to reduce vibration during movement. But the bulky, heavy design also results in low efficiency, high energy consumption and easy occurring of personal injury accidents. Currently, manipulators are experiencing a light-weight trend. Light-weight designs can enhance the ratio of the payload and the self-weight of manipulators, lower the driving power and the bulk of joint motors and greatly increase the safety of manipulator operation. Although there are many advantages of light-weight designs, the lighter weight will increase the flexibility of manipulators significantly, which will make vibration problems stand out. This raises new challenges of manipulator control to ensure operation accuracy. Peng Chen is with University of Chinese Academy of Sciences, Beijing, 100049, China. the conclusion that the joint vibration can be suppressed using vibration torque feedback PD controller to control the output torque of flexible joints. Shan et al [11], Cao et al [12] research active vibration control of flexible manipulators on the basis of piezoelectric materials. They control the piezoelectric actuators with fuzzy control methods. And the link vibration of 2-DOF flexible link manipulators is suppressed successfully.About the vibration control of manipulators, another straightforward idea is to minimize the introduction of vibration. This can be achieved through the motion planning method. The field of motion planning of manipulators has also been researched by many scholars. Zu et al [13], Yang et al [14], Chen et al [15] research the inverse kinematics optimization of redundant manipulators. These researches mainly focus on how to optimize manipulator trajectories, including singularity avoidance, joint limitation avoidance and obstacle avoidance. Fu et al [16], [17], Ju et al [18] research in the field of combining intelligent algorithms with the polynomial interpolation method. The purpose of their researches is to minimize the P-to-P ...