Research On Cooperative Welding Path Planning For Multiple Robots

Welding of Body-in-white (BIW) is one of the four major automobile manufacturing process, occupying an important position in the modern manufacturing industry. In order to meet the demand of mass production, high rhythm and high-efficiency BIW welding production, multiple welding robots are needed to perform the welding tasks. In the actual welding process, welding robots are required to complete a number of solder joints, as well as to avoid interference with other welding robots. Therefore, how to solve the plan planning problem of multiple welding robots are significance to reduce the welding time and increase efficiency of welding production.This paper mainly study the path planning method of single and multiple welding robots. Firstly, the composition of BIW and welding line process are researched, BIW modules and solder joints, spot welding, robots and fixtures which affect the results of multiple welding robots path planning were analyzed. Base on the analyze of overall welding mission planning, a math model (traveling salesman problem) for single robot welding path planning is obtained. After comparing the advantages and disadvantages of the traditional algorithms, intelligent algorithms and other three methods, the particle swarm optimization algorithm (PSO) is selected as the single welding robot path planning algorithm. And a welding robot path planning of a station was simulated in MATLAB.Secondly, the multiple welding robots path planning method was studied. The objectives and constraints of multiple welding robots path planning were analysed, and the multiple welding robot path planning process is obtained. Particle Swarm Optimization (PSO) algorithm based on coevolution algorithm was selected. Under the coevolution algorithm model, the multiple welding robots was divided into several single welding robots to solve the problem. The PSO algorithm was used to evolve the path planning of single welding robot. At the same time, the welding robots also communicate and coordinate with each other to compare the position and judge whether the interference occurs. This paper also build math model of backpack and anti interference between welding robots. A path planning model of two welding robots in a station was build and simulated by MATLAB program to verify PSO algorithm based on coevolution algorithm.Finally, simulating in ROBCAD and using the user interface language ROBUIL to write the interface. A ROBCAD application is developed in.NET programming environment, Using ROBAPI function to operate the ROBCAD object, and PSO algorithm application is integrated into ROBCAD.