| Mold is the basic equipment in economic development and indispensable tool in machine building, chemical industry, electronics industry etc. Mold manufacturing and design level has become an important symbol to measure a country's industrial development level. Polishing is the last finishing process in mold processing with the main objective to reduce surface roughness. The working efficiency of mold polishing is greatly increased with the development of multi-degree of freedom polishing system. But for a long time, one of the key issues which perplex the breakthrough on the substantive effect on multi-degree of freedom polishing system are the location attitude control and polishing force control of polishing tool during polishing.In order to solve this problem, in this thesis, the ideal attitude control parameters and ideal line speed were obtained in the flexible polishing process by study on the key parameters of the polishing removal model with the combination of experimental data analysis. The interference-free polishing mathematical model was also established. Based on this, an attitude control algorithms for polishing tool was proposed in order to make sure that the polishing parameters of each contact point on free-form surfaces workpiece were same in the polishing process. The control algorithms for ideal attitude polishing head were realized on industrial robot Motoman-HP20. The main research contents are listed in the followed:1. A free-form surface polishing model was established based on in-depth study of equation Preston, then the mathematical model of theoretical removal function was obtained in this experiment. The ideal control parameters were obtained through series of attitude control parameters experiments.2. The ideal attitude control algorithms were realized on industrial robot Motoman-HP20. The path trajectory was planned used default CNC machining tool path generation algorithm on software Pro/E adopt Zig-Zag mode; Path equidistant planning algorithm was proposed in order to solve the problems such as trajectory too dense of numerical control isoline method, which impacts the polishing efficiency; Ideal linear speed control method was also proposed to avoid bottleneck interference in trajectory planning which caused by small radius of curvature on workpiece free surface.3. Pole parameters of Motoman-HP20 were analysed. And the correctness and feasibility of trajectory planning algorithm and kinematics algorithm were verified through ideal attitude control simulation program using GUIDE kinematics module of MATLAB.In this thesis, location attitude control and polishing force control of polishing tool during polishing were researched in detail which worth to actively explore and expand in the future. At the same time, the development of multi-degree of freedom flexible polishing system based on attitude control played a positive promoting role on industry development. |
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