Research On Key Technologies Of Internet-based Telerobot Control System

For the limits of artificial intelligence and other technologies, it is hard to realize autonomous robot task for a long distance. While, telerobot system combines the intelligence of human and robot, which extends human’s perception and operation ability. It can complete tasks in dangerous, hostile even extreme environment instead of human. So it has wide application prospect in many fields, and it is a frontier topic and a research focus needed to be researched at present.Recent years, with the fast developments of virtual reality and Internet, new vitality and power are injected into traditional teleoperation. But the communica-tion delay, delay jitter, bandwidth constraint and bandwidth change all have bad effect on teleoperation system. In addition, man-machine interaction, the improvement of robot intelligence and the rational distribution of the operator’s intelligence and robot intelligence are not resolved well. So, research on the key techniques of Internet-based telerobot system has significant practical meanings. The problems of friendly man-machine interaction technology, network time delay and predictive control technology of teleoperation, automatic obstacle avoidance of robot are studied in this paper. The main researches are as follows:The man-machine interaction mode with dual-virtual model overlapping display is proposed for telerobot and the operator centered interface is designed aim at the problem that the operator can’t obtain enough perception information of task state to determine the robot task state correctly for the lack of friendly man-machine interaction in the available interaction mode of the telerobot system. So the effect of video feedback delay can be effectively avoided, and the working performance and the operation efficiency of the system are improved.The time-delay of the telerobot system is tested; the reasons for network time-delay and the relationship of transmission protocol, distance, time quantum and packet size are researched. In order to guarantee the operator finish the task with safety and high precision, a time-delay predictive algorithm based on Smith predictor controller and RBFNN is proposed. It adopts time-delay predictor based on RBFNN to correct the parameters of Smith predictor controller real-time at local control end. It makes the system avoid the effects of variable time-delay and packet loss, and run steadily without the influence of time delay. Simulation results based on Matlab prove the effectiveness of the algorithm.The development of automatic obstacle-avoidance control algorithm is rather slow due to the limits of mechanical structure and strong coupling of the industry robot. Especially, the robot working in 3D space don’t have appropriate control algorithm to avoid obstacle automatically. In this paper, the RMRC control algorithm is further studied and a rather practical potential function is re-constructed, which is applied to avoid static obstacles and dynamic obstacles real time in the task space of Motoman robot. The obstacle-avoidance effect of the algorithm is simulated with Matlab. Adopting this algorithm, the automatic obstacle-avoidance of industrial teleoperation system in 3D space is resolved and the autonomous ability of remote robot is improved.A multi-control mode timely automatic switching strategy is proposed to solve the problems of present telerobot system, including poor man-machine interaction coordinated ability, single operation mode, low system efficiency, operator in the state of continuous and boring direct control, unstable caused by nimiety intervention of the operator, etc. Ii is done after a model built to test the response time of the operator and to analyze the effect of response time on system performance. This strategy improves the decision ability of the system and realizes coordinated working of the operator and the robot. The task process of telerobot system with multi-control mode automatic switching timely is simulated with CPN and the rationality of the control strategy is proved.At last, a telerobot system based on Motoman-SSF2000 robot, graphic workstation and other equipments is established. Related experiments are carried out based on this experiment platform and experimental results are analyzed to prove the above theory, method and control strategy.