Integration Of MAS-Based Tele-Robotic Welding System

With the expanding of human activities, welding technology is widely applied to some assembly and maintenance work underwater, in space and nuclear environment. It is necessary to use robot to execute weld task instead of human in the extreme environment. Now relevant technologies do not yet permit a totally autonomous remote welding operation, tele-robotic welding with the help of operators have been paid more attentions.In an intelligent tele- robotic welding system, it is greatly necessary to monitor the quality of seam and track the path of robot real-time, and monitor the processing of welding remotely. So physical device resources with certain independence and automation are imported. Because of these physical resources tele-robotic welding system possesses some inherent distributed characteristics. Thus it is possible and necessary to control tele- robotic welding system with the distributed multi-agent cooperation technology.In the viewpoint of application, the basic hardware configuration of tele-robotic welding system has been firstly introduced. And then on the basis of analyzing the production process and control mode of tele-robotic welding, the multi-agent model of tele-robotic welding system has been presented.The communication and cooperation mechanism of tele-robotic welding system were studied. Message transmitting in point to point, message encapsulating in KQML, message contents described in KIF were selected for information exchanges. By analyzing negotiation based coordination methods and Contract Net Protocol, the cooperation model of"station based on requirement, mount guard through competition"is presented.We have constructed a tele-robotic welding multi-agent system, which contains welding robot, tele-operation system, laser scanning welding seam tracking sensor, force sensor and seam molten pool monitoring system. Based on the distributed control characteristics of multi-agent system, all subsystems are monitored, managed and coordinated through corresponding resource agent.At last tele-teaching experiments by the cooperating of laser scanning welding seam tracking agent, force agent, welding robot agent and operator were fulfilled.