Research On Teleoperation Control Of Mobile Manipulator Using Wave-based Method Through Internet

Operator can extend his intelligence to remote environment as well as improvingworking efficiency and guaranteeing his safety when interacting with the environmentvia teleoperation system. At present, teleoperation has been widely used in many fieldssuch as space exploration, telesurgery, deep sea exploration, nuclear industry, militarytraining, etc. Adding force feedback to teleoperation system could improve thetelepresence of environment and the ability to complete complex tasks. However, Timedelay incurred and influenced by transmission speed, distance and network load couldinduce the instability of system. Wave-based method could guarantee the passivestability of the system under the any fixed time delay, but will lead to transparencydecline. In this paper, a wave-based control method is studied to ensure the passivestability under varying time delay, and improve system transparency meanwhile. Withthe help of critical control methods studied in this paper, the six degrees of freedommaster hand can realize the control of redundant mobile manipulator.Firstly, analyze the forward and inverse kinematics of the manipulator according tothe robot configuration and present joint angles; put forward a redundant inversekinematics control algorithm based on joint analogy and joint optimization according tothe structural characteristics of the mobile manipulator. Conduct statics analysis of themanipulator and derive force Jacobian matrix. Propose a control strategy based onmanipulator singularity and the master workspace, by the use of which the control ofmobile manipulator by Phantom Desktop is realized. Experiments show that with thisstrategy master could manipulate the slave robot in real time.Analyze the passivity f the traditional wave variable method under varying timedelay and put forward a wave-based algorithm of three channel based on disturbanceobserver for mobile manipulator teleoperation system, which solve the passivityproblem of wave variable under varying time delay. To take advantage of the passivestability of the varying time delay control algorithm and the good transparency of waveprediction method, these two algorithms are combined so that the overall performanceof the system will be improved. Analyze and compare different control structures usingtransparency evaluation methods. Results show that the proposed algorithm has bettertransparency. Simulation results verify the effectiveness of wave prediction methodunder the position correction control on the slave based on varying time control.Finally, build experiment platform of mobile manipulator teleoperation system.Conduct experiment of redundant control algorithm, and results verify the effectivenessof it. Experiments conducted under fixed time-delay during which manipulator moves from free space to rigid environment verify the effectiveness of the algorithm of threechannel control structure.