Research On Robot-assisted Gasbag Polishing Motion Control And Trajectory Planning For Mould

In order to solve the problems of manual polishing on free-form surface of mould, such as shortage in skilled labor, low efficiency in polishing, variance in polishing quality, large time-consuming and the monotonous of working procedures, many researchs have been done. However, the only feasible way is to realize an automatic system of polishing the free-form surface of mould.In this paper, a robot-assisted gasbag polishing experimental system is built on the basis of a novel Spinning-Bulged-Complaint Tool and an industrial robot MOTOMAN-HP20. Besides, the kinematics of industrial robot and the gasbag polishing trajectory planning of mould also have been throughly analyzed and discussed.In the first part of the paper, an experimental platform of the robot-assisted gasbag polishing system is built as the free-form surface polishing technology has required. Then the paper moves on to study the gasbag polishing technology and its principles, which is applied in the novel Spinning-Bulged-Complaint Tool. These priciples include polishing parameters which affect the gasbag polishing effect, contact control and contact area, stress analysis of gasbag polishing area and so on.Later, the paper gives a comprehensive analysis of MOTOMAN-HP20's kinematics. Beginning with a general review kinematic theory of robots, the paper discusses ways to decribe robot pose, deduces a robot-link transformation matrix, and sets up equations for robot kinematics. Based on these steps mentioned above and a further combination with the MOTOMAN-HP20's structural parameters and joint variables, the equations are worked out for forward and reverse solutions.Furthermore, the paper includes a deep discussion about the trajectory planning of robot gasbag polishing. According to different robot motion controls, the trajectory planning falls into two catogories: online teaching programming trajectory planning and off-line programming trajectory planning. Although their perspective advantages and disadvantages are both raised, it is the realization of off-line programming trajectory planning that gains more focus.Last but not the least, the single-factor comparative experiments are done on the basis of the orthogonal experiment, to plan for three different polishing trajectories to polish the free-form surface of mould. Finally, with the resultes attained from experiments the paper will sum up rules about the influence of the polishing trajectories over polishing quality and give these rules a reasonable analysis and explanation.