OPERATOR-IN-THE-LOOP SIMULATION OF A REDUNDANT MANIPULATOR UNDER TELEOPERATION

For an interactive simulation of 7 degree-of-freedom redundant manipul ator under teleoperation, this paper describes an iterative form of re solved-motion rate control in which the constraint Jacobian is constru cted on-line in real time and used in the pseudoinverse method as the manipulator's is teleoperated. The manipulator's tasks may involve tra jectory following in free space and frequent contact with the environm ent through pick-and-put operation. The operator's command is interpre ted as a series of increments in Cartesian space, and then the constra int Jacobian is developed between two successive increments by viewing the predecessor as the initial configuration and the successor as the target configuration. The pseudoinverse of the constraint Jacobian th en generates necessary changes in joint variables and subsequently joi nt torque. The Jacobian constructed in this way enables us to treat bo th free motion and environmental contact in the same way. The simulato r is built on a two-processor IRIS workstation, with one processor for graphics and the other for dynamics and control analysis. The simulat or has a potential for training the teleoperator, developing operation al scenarios through visualization of the simulation, and testing the design of operator-machine interface.