Technical Research Of Robot Offline Automatic Programming For Complex Curve Machining

In the age of Industry 4.0 and "Made in China 2025",the manufacturing industry is booming,the use of robots is more and more widely,and its operation scenes are more and more complex and changeable,which puts forward higher requirements for robot programming technology accordingly.In the generation of complex curve processing program,the existing teaching programming and off-line programming are cumbersome and difficult to use,hence this thesis studies the off-line automatic programming technology of robot to solve these problems and improve the programming efficiency and programming quality.Pipe intersecting line is one of the main forms of complex curve,which is widely used in nuclear power,pipeline engineering,petrochemical engineering and other fields with a large number.Therefore,in this thesis,pipe intersecting is taken as the application scenario of offline automatic programming technology,and complex curve modeling,cutting planning,welding planning and automatic program generation problems in pipe intersecting scene are studied.The main work of this thesis is as follows:(1)Analyze the "guide rail+robot+positioner" processing platform,with the robot,positioner,tool and workpiece coordinate transformation to decouple the robot joint angle and workpiece work trajectory;Establish MDH model of ABB 2600-20/1.65 arc robot and provide complete inverse kinematics analysis process based on geometric method.(2)Propose calculation steps of intersecting line and complex curve translation and projection line under the dihedral frame.Propose generating methods for establishing intersecting models in type of branch pipe insert,branch pipe external,two docking,master pipe groove and branch pipe groove based on complex curve.Besides,combine these steps or methods with MATLAB to verify by model visualization.(3)Based on the pipe cutting model,provide cutting path planning method with cutting radius compensation and calculation method of cutting path transition arcs,including piercing(or cutting)transition and stopping transition.Based on the cutting path,a cutting trajectory planning method adapting to cutting thickness and cutting trajectory shape is proposed.The trajectory shape interpolation method is realized based on S-type speed curve,which can strictly constrain the trajectory shape and calculate the cutting direction.(4)The welding path planning models based on the dihedral frame for the single-layer swing welding and multi-layer swing welding are proposed,in which the welding spots and welding direction were calculated automatically.Based on the path planning of welding,the methods of welding strip operation and the methods of welding path planning point by point operation are proposed.(5)For the realization of machining trajectory of processing platform,the transformation methods of workpiece machining trajectory to robot operation trajectory and positioner trajectory is provided,and the methods of welding torch attitude adjustment and automatic generation of tool coordinate system are provided.(6)For ABB robot,the automatic generation flow of joint angles trajectory and the RAPID program generation based on joint angles and positioner angle are provided and the program is verified by RobotStudio.