Research On Construction Telerobotic System With Telepresence Based On Virtual Reality

Teleoperation system with master-slave robot can work under uncertain or extreme environment instead of men. The telerobotic system with telepresence can provide the operators the visual and force feedback, which can make the operator make the right decision when taking the operation, enhance the efficiency and quanlity of the operation. The researches on the technology related with telepresence are being paid more and more attentions.This paper has set up a telerobot system with force telepresence and visual telepresence based on the analysis of many telerobot systems with telepresence in home and abroad. The system is mainly composed by manual controller with force feedback, 4-DOF construction robot, bilateral servo control subsystem including position servo subsystem and force telepresence subsystem, video telepresence subsystem, and the Internet communication subsystem. Also, the structures and functions of all subsystems are being discussed in great details.The telepresence telerobotic system based on Virtual Reality works like this: The length sensors and press sensors fitted on the robot used to measure positions of the robot joints and the resistance. These messages will be send to the virtual reality workspace to form the visual telepresence. In the meantime, the resistance will be transmitted to the manual control device and formed the force telepresence. Compared with operating with the prompt by image only, the massages are transmitted easier and quicker than the image, and the working efficiency will be improved greatly, the quality of the teleroperate will improves too. The operator can get the information on time and operator the robot on different view points. Compared with the pre-operate strategy, the visual feedback can show the real state of the robot.The experiments was taken in the LAN of JilinUniversity. And using the immediate force feedback control strategy, the results of the experiments show that this system has a good performance in force feedback effect and the position control, which prove that this system is efficacious and workable.Combining the research of theory and experiments, we have accomplished main research work as follow:1. Based on the research on the time delay features of telerobot systems, this paper designed a new kind of telerobot system based on Virtual Reality, and make the concept come true. The experiment shows that this system haves a good ability to control.2. The control information and the feedback information are transmitted by Internet based on TCP/IP protocol, which can make the stability and reliability of the data in transitions better. In the process of comunication, we set some restrain of of sending the control information, which can send only by receiving the feedback information.3. Analyze the kinematics formulation for 4DOF hydraulic construction robot, and established mathematics model for the relationship between hydraulic rod length and joint angle of the manipulator. These make the foundation of the 3D graphic simulation and high precision position control of the telerobot system.4. Build the visual feedback subsystem. The model of the robot and the scene of the work spot is build by Multigen Creator, and the information of the operating object is get by Stereo Visual System and rebuild by OpenGL, all the movements of the Virtual Reality units are driven by OpenGVS.5. Based on the analysis of the image feedback and virtual pre-operate telerobot system, we designed the experiment to test the time delay of the Internet and test the time delay of these teleoperate system. Through the experiment it can be see that the teleoperate system built in this paper has obvious advantages on saving the problem of time delay.The construction telerobotic system with telepresencebased on virtual reality gives the operator telepresence timely and effectively by the force feedback joystick and the visual feedback system, and decrease the impact of timedely on the telerobotic system efficiently. The strategy of the Internet communication and the visual feedback system has a big significance for solving the problem of the timedelay and improving the performance of telerobot system.