Research On Trajectory Planning And Compliant Operation Of Economical Polishing Robot

Polishing is a common process in machining, which is also a kind of very important process and ultimately determines the surface quality of workpiece and also affects the service life time of the workpiece indirectly. With technology advances, many kinds of polishing method are provided, but mechanical polishing method is still the main method in polishing process, especially in the field of machinery manufacturing. Usually, traditional mechanical polishing methods mainly rely on artificial implementation, which not only heavily depend on labor resource,but also cause significant damage to operator’s health. Now, robots have replaced humans in many places of manufacturing, which save cost, improve the efficiency and the quality of product. Because of the characteristic of simple structure, low cost, convenience in development and maintenance, rectangular coordinate robots are used by a lot of automation equipment manufacturers. So this paper will try to explore the rectangular coordinate robot in polishing process, and to make the automatic polishing happen.This thesis established a kind of polishing control system prototype based on rectangular coordinate robot,by using PLC, servo drive and servo motor and polishing tool, pneumatic components, etc. Meanwhile, this thesis also set up a test system combining with Preston theory and the relationship between the relative movement of polishing tool and workpiece, and designed three kinds of polishing trajectory schema. Polishing trajectory is planned on the plane firstly, then projected to the three-dimensional space.And then, a kind of upper layer control system was developed, by using the Visual Studio software development platform and Visual C++ programming language, providing the functions of system initialization, selection of polishing mode, choice of polishing force control pattern. We also proposed a kind of flexible control scheme based on contact force control of robot, trying to achieve the axis position control through control the polishing force, so as to realize the three dimensional surface polishing.This thesis has achieved multi-axis control through the control structure of PC+PLC+sensor,then made a preliminary exploration and research in robot flexible control, putting forward an active protecting method based on the contact force of robot, and realized active escaption by driving each of axis in the control of PLC.Finally,some factors affecting polishing performance are discussed through physical experiments.Functions of the control system are validated with results of polishing surface, and future research emphasis and direction are presented.