Research On Autonomous Arc Welding Robot Control System And Welding Trajectory Planning

At present,with the continuous development of science and technology,robot technology is also in constant progress,and the demand for welding robots in industrial manufacturing is also increasing.However,there is still a big gap between the average use density of welding robots in China and the developed countries in the world,which is mainly due to the adaptability and ease of use of welding robots.In order to reduce the difficulty of using welding robot and improve the usability and adaptability of welding robot,we independently research and develop arc welding robot control system that integrates robot upper computer,teaching device,motion controller and digital welding machine.Therefore,from the aspect of improving the adaptability and ease of use of the arc welding robot,this paper studies the control system of the autonomous arc welding robot and the arc welding trajectory,mainly including the hardware system composition of the arc welding robot,the overall design of the upper computer software system and the arc welding trajectory algorithm.Firstly,the hardware system of arc welding robot is introduced and the hardware system platform of arc welding robot is built.The hardware system mainly includes robot body,upper computer,teaching device,motion controller,electrical control cabinet,digital welding machine,wire feeding machine,Welding torch,positioner and ground rail,etc.Secondly,according to the structure and functional requirements of the arc welding robot control system,the adaptability and usability of the arc welding robot are improved,and the overall design of the software system of the upper computer of the arc welding robot is carried out.The overall design of the upper computer software system is described in detail from six aspects:the man-machine interface of the upper computer,the data processing of the upper computer application program,the communication between the upper computer and the demonstrator,the communication between the upper computer and the digital welding machine,the communication between the upper computer and the absolute value encoder,and the welding process package.Then,in order to improve the welding precision of the arc welding robot,the end welding torch of the arc welding robot is calibrated by a six-point calibration method to determine the positional relationship of the welding gun relative to the end flange of the robot.In order to improve the welding quality and reduce the number of welding passes,space vector interpolation method is used to study the algorithm of generating 8-character swing arc trajectory for space line and space arc.In order to improve the adaptability and richness of welding,other arc trajectory algorithms of arc welding robot are studied.In order to solve the problem that the actual velocity of welding arc swing trajectory is not equal to the given terminal velocity of the robot,the velocity planning of arc swing path of arc welding robot is carried out,proposed an optimized extended line displacement method.Finally,in order to verify the effectiveness of the autonomous arc welding robot control system function and the swing arc trajectory algorithm,experiments were carried out on the platform of the autonomous arc welding robot control system.The actual position and posture relationship between the welding torch and the end flange of the robot is determined by the calibration experiment of the robot end welding torch.The validity of various arcing trajectory algorithms is verified by the arc trajectory drawing experiment and welding experiment.The validity of the linear velocity planning algorithm at the end of the arc trajectory is verified by the motion data of each joint during the arc swing motion of the arc welding robot observed by the autonomous arc welding robot control system.