Study For Building Modle Of The Polishing Process Of 5-dof Parallel Robot And Its Path Planning

Polishing is the final and one of key procedures in machining, which can not only increase surface finish and improve surface quality, but also positively affect the local stress concentration. Polishing workpieces with complicated surfaces is still preformed manually in present-day. This process is always time-consuming and labor-consuming and also demands for high-level polishing technology and rich polishing experience. Sometimes useless workpieces are produced due to mistakes made in the process of polishing. The 5-DOF polishing robot can solve the above problems caused by manual polishing, and thus satisfy the needs of high efficient machining with great quality for mordern industries. Compared to machine tool, robot has better polishing performance and capability of machining workpieces with more complex surfaces, due to the reason of a more dexterity, the robot can polish the free form surface in the direction which plumb to the surface. But because of the technology complexity of developing and applying robot-assisted polishing automatic system, including producing a polishing tool which is more similar to the ideal model, controling the polishing parameter during the polishing process, and holding the stable polishing force, designing efficient tool path, automatic implementation of polishing plan and avioding singularity points. So the abroad and home automatic polishing systems which put into market are rare. The purpose of our research is studying some problems confronted when designning a 5-DOF robot with the wool polishing block as the polishing tool, mainly containing the following aspects:After fully understanding the specialarity of the parallel mechanism, static analysis is done for the key part of the mechanism and as a result, the static equilibrium equations are gotten. Using Pro/MECHANICA for finite element analysis, the key components of polished robot is described for the entire analysis procedures, and the accuracy of the structure optimization is verified.After fully understanding the situation of using polishing tool made of wool block, the model of the polishing process and its qualifications was proposed. The data of the free surface under the workpiece coordinates was regarded as inputs, the position and orientation of the center point of the polishing tool was computed as the output data. The polishing process with the polishing tool vertical to the surface can be achieved.Using Hilbert curve as basic elements, a path planning method that can guarantee of high precision machining free surface was discussed. The solutions to the problem of non-square projection of the machined surface was given. The distance between the polishing trajectory was calculated. An analysis of avoiding singular based on the redundant motionality was given.This study plays a role in providing theoretical value for the 5-DOF polishing robot with the polishing tool made of wool. This study also plays a role in producing efficient processing and high-quality product to meet the modern industry.