Research On Auto-Programming System For Free-form Surfaces Belt Grinding Robot

In modern times, technology of machining and molding for free-form surfaces is holding the balance of modern manufacturing. In automobile industry, electronics industry, aeronautics and astronautics industry and some new high-tech industries, higher and higher requirements are made for quality and efficiency in machining die and mould with free-form surfaces. And the requirements on the die and mould technology for high quality,high efficiency and low cost have been the focus of the manufacturing. Industrial robots are used in free-form surfaces polishing because of their excellent characteristics which are different from other tools. An excellent auto-programming system can put robot in good use.Firstly a new robot grinding system which integrated robot and advanced processing method will be introduced. The system is composed of the Robot sand-belt Grinding system and PC machine.The abrasive tool is fixed on the flange of the robot arm. The finishing of the surface is realized by the motion of the arms.The whole system are shown in Fig.1 and Fig.2.Robot system works based on robotic grinding tool's trajectory planning in precision machining which determine the way and efficiency the robot complies. The free-form surfaces of space piece are cut in this paper by a series of some isometric parallel planes enable the grinding tool to feed along the space curve which is the intersect line of the cutting plane and the free-form surfaces and so finish the grinding for the free-form surfaces this method of grinding is called longitudinal movement programming as shown in Fig.3.Kinematics of robot by which can get variable of each joint with the tool's position and pose to drive the motor is the foundation of auto-programming systems. Applying homogeneous transformation for the coordinates frames, the robot's position and pose is depicted and found the kinematics model of robot in this paper.According to trajectory programming and specific constraint conditions, the robot's positive solution and negative solution are deduced (see formula 1) . The negative solution of each joint is simulated in this paper. And the results are shown in Fig. 4.The results of simulation indicate that the model of kinematics and joint positive and negative solutions are correct in grinding free-form surface. use the robot own languageare introduced. The Windows xp operating system and Object Oriented Visual C++ are used to develop the auto-programming system for robot according to the method provided by former paragraphs.The system interface is developed to reach the aim of understanding simply and easily operated and will solve the problem of manual programming. By selecting curve form and setting initial parameters, when the OK button is clicked the software can produce program for free-form surface grinding robot automatically.Then the program is introduced into grinding robot to do grind-processing experiments. The processing experiments verified that the system is stability and feasibility. When the workpiece is grinding, the experiments showed that the thinner of the belt particle size can get the better the processing effect when the belt velocity and other conditions are ascertained;and the higher velocity also can get the better processing effects when the belt particle size and other conditions are ascertained.