Research On Off-line Programming For Industrial Robot Based Cutting Process

With more and more applications of industrial robots in many fields, such as handling, welding, painting, assembly etc, the traditional on-line teaching programming method gradually exposes disadvantages, such as inefficient programming and low teaching precision, which have direct influence on the production efficiency and the usage of industrial robot.This thesis studied the off-line programming techonologies of industrial robot for cutting machining, so that the APT source file of cutting location outputed by CAD/CAM system can be transformed to RAPED instructions of ABB IRB6600 industrial robot, and the trajectories of cutting machining can be tested and checked through the kinematics simulation.The main contents of this research and the chapters arranged for this thesis are as follows:Chapter one overviewed industrial robots and its application in the field of cutting machining, subsequently introduced the concept of industrial robot off-line programming and the research status and developing trend of this technology. Also, the major contents and the general structure of this thesis were given.In chapter two, the basic kinematics theories of robot were introduced. Using homogeneous transformation theory, the kinematics model of ABB IRB6600 industrial robot was established, and the forward and inverse kinematics equations were obtained. The results of the Matlab simulation show that the kinematics model and the forward and inverse kinematics equations are correct. Moreover, the solutions of the inverse kinematics equations are not unique.The feasibility of the transformation from APT source file of cutting location to RAPID instructions was analyzed in chapter three. The characteristics and related concepts of APT source file and RAPID programming were presented. The APT source file includes infomations of cutting location, axis vector of cutter and cutting velocity, while the RAPID instructions need informations of position, orientation, axis configuration and moving speed of TCP (tool center point). Fortunately, there are relationships between the informations of them. The analysis results show that the transformation from APT source file to RAPID instructions is feasible.In chapter four, the key technologies in off-line programming of industrial robot were studied, including the computation method of TCP position and orientation, the estimation method of axis configuration parameters, the coordinate transformation, the cutter radius and length compensation, and the linear&circular interpolation algorithm for cutting machining simulation.In chapter five, the implementation and applications of the off-line programming for cutting machining by industrial robot was introduced. Based on the transformation algorithms of RAPID instructions, the data structure was designed, and the off-line programming software which includes the code transformation module and kinematics simulation module was developed, using Visual C++ and OpenGL. Also, the calibration method for trajectories of cutting machining generated by the off-line programming software was studied. Both function modules of the software and the off-line programming methods were tested through the example of the arc tooth-like workpiece machining.In the last chapter, the conclusions of this research were drawn, and the further research work was suggested.