Path Planning For 6R Spot Welding Robot Based On Collaboration Between Jointspace And Workspace

The way of welding manufacture is changing with the development of industrialization and the improvement of manufacturing industry.The Application of the spot welding robot has gradually replaced workers which greatly improved the welding quality.The output of the product is diversified and the working environment of the operator is optimized.Spot welding robot has been widely used in manufacturing industry especially in welding of automobile body,and it has become the mainstream of automobile manufacturing industry.Improving the overall performance of the robot is the key task in robot research and the important symbol of measuring the application of robot processes.When the spot welding robot is working,the speed should be fast and the position should be accurate to which it can reduce the impact and vibration produced when moving and keep the accuracy of the welding spot.The path planning problem for spot welding robot is a hot topic in the field of the research,When the robot moving between several welding spots and the welding gun moving according to order of the welding spot rules,it can get the good dynamic characteristics and the shortest path in the space.Research on the joint trajectory planning method and the the shortest path of welding regarding 6R spot welding robot as the research object,which for the robot arrived at each welding spot can accurately the position of the robot posture,from one welding spot to the another without shock and the total path length is shortest.First of all,according to the D-H method to establish the mathematical model of 6R spot welding robot,deducing the transformation matrix of the adjacent bars and the position equation of the welding gun on the end-effectors,and completing the graphics and animation analysis of 6R spot welding robot through three-dimensional software.Secondly,choosing the better method from 5 times polynomial and cycloid movement to plan the angle displacement in jointspace which dynamic characteristics of the robot are ensured when it moves from any welding point to the adjacent welding point.And then,the set of the possible ergodic paths of the spot welding robot passing all welding points are listed based on the principles of combinatorial mathematics and the optimal welding path sequence is given by combining with the relationship between jointspace and workspace mapping and all possible path length dynamic numerical.The planning method is verified by an example,which is discussed in the last part.At last,simulating the trajectory of robot in MATLAB Robotics toolbox which obtained the smooth trajectory graph of the end-effector and the continuous and smooth angle,angle velocity and angle acceleration curve of 6R spot welding robot.Through calculating comparative analysis coming to a conclusion is that using 5 times polynomial planning angle displacement in jointspace is better than cycloid movement which the welding path is shorter.It can be see the whole motion smoothly without severe vibration and shock,effectively maintaining the accuracy of the welding spot,making robot gets good dynamic characteristics,improving the stability of 6R spot welding robot,and prolonging the working life of the robot.