Research Of Virtual Reality System Of Telerobotics System

This is a tele-operation system with master-slave robot at thecore. It is mostly used in uncertain or extreme environments with hightemperature, heavy pressure or high radiant. Such as the universeexploiting, under ground exploiting, seabed exploiting, and therushing to deal with an emergency in the fire, flood, earthquake, etc.In these environments, the quality of operation is correlation withthe ability of getting information (such as force, vision, etc.) aboutthe slave side. Based on the normal vision teleoperation system, weadded a virtual reality scene to improve the vision information thatcan be got by the operator, which make the operator accomplishcomplicated and exact operation. With the development of society andeconomy, higher quality and acute of teleoperation is required, So thistelerobot with the prompt of highly virtual reality system is gettingmore and more attention.The following is the theory of operation:A video system is fixed in the telerobot system, which transmitsthe images of the working spot to a screen in front of the operator.On the other hand, digiclops camera transform the information of theoperated object into digital signals, then a virtual scene with robotis built. The operator can do the controlling operation with forcefeedback joysticks at safe location, then the controlling informationis transported to the robot in the working spot via a wirelesscommunication tache. The force received by the robot is transportedto the joystick and the force feedback process is done. The movementof the robot is transported to the graphics robot in the virtual scene,which will move in response immediately. During the real operating course, the information data receivedfrom video system is only 30%～50% of that from direct operationfor the restricts of communicate technology and the amount and positionof videos. So the operate effection is not very good. Based on theformer vision feedback system, a visual scene is added, which canimprove the working efficiency for over 50%. The three dimensiongraphic simulation software is designed with Visual C++ and OpenGLgraphic interface using object oriented method, which conquers therestriction of most of the simulation software based on graphicworkstation, realizing the immediate simulation of the graphic robot,and we can own knowledge property right of ourself. With thedevelopment of society and economy, there are more and more demandsin the rescue area. So this tele-robot with the prompt of highly virtualreality system will be of unique superiority in the rescue area. Andit should have great effect on society and economy. As the command of the operator could be responded by the graphicrobot immediately without time delay, and the movement of the realrobot is the reappearance of the simulating robot, the introductionof the virtual reality technology into the teleoperation system helpsto solve the large time delay to some extent of the telecontrol system.At the same time, the operator could accomplish the operation easilywith the much more vivid visual telepresence information by changingthe viewpoint and view angle of the virtual environment, which can notachieved by the single video feedback. Also the system works well evenwhen the task is shut out by parts of the robot or when the vision isdim and blur because of the atrocious working condition. The telerobot system with telepresence in Yamada lab has thefollowing characters: A telerobot system with telepresence based on eletron hydraulicservo control system has been built, whose characteristics areteleoperation, high precision position control, force telepresence,video telepresence and wireless communication. If it is applied inextreme environment, the working efficiency can be raisedremarkablely; Aimed to the shortcomings of video feedback, video inspectinvolved visual reality technique is used, that is to add computergraphics robot and virtual scene. The introduction of the virtualreality technology into the teleoperation system helps to solve thelarge time delay to some extent of the telecontrol system. At the sametime, the operator could accomplish the operation easily with much morevivid visual telepresence information by changing the camera andviewpoint of the virtual environment, which can not be achieved by thesingle video feedback; The virtual reality world is built on the information of real robotand objects via digital graphics technology, which is able to reappearthe condition of working spot and improve operate and telepresence. Based on the analyze of the telerobot system in Yamada lab, we madea dissertation of the vision subsystem and force feedback subsystemat the part of struct and programming. On the hand of force feedbacksubsystem, we introduced the struct and mathematical model of themaster-slave system consists of joystick and hydraulic system. Thenwe discussed the master-slave controls used now and those improved byYamada lab. On the hand of vision system, we labored the build processand some important functions of the VR system now. Then we improve thesystem on the following: As the vision feedback of the system is mainly based on the VR world,the position of camera and viewpoint in the VR world is very importantto the working efficiency and security of robot. It has been testifiedby experience that the best project is the camera and viewpoint movewith the folkglove of the robot. We proposed two new algorithms basedon the former project, and made experiment on them to validate theircapability and analyzed the result to elect the best one. During the real working time, the movement of VR robot is mostlybased on the moving information from the robot in working spot. It hasbeen proved that the VR robot can't always catch up with the real robot.