The derivation of the Jacobian matrix for a novel six degree of freedom parallel manipulator is presented in this paper. A force decomposition approach is used to compute the Jacobian. The parallel manipulator consists of a base plate, a top plate, and three connecting legs with all revolute joints. The key to the Jacobian formulation presented here is the derivation of a mapping from the applied end-effector force and torque to two force components at each spherical joint. Each leg of the manipulator can then be treated separately and the actuated joint torques can easily be computed from these spherical joint forces.>

The effect of the joint bandwidth of the slave arm on telerobot system performance was investigated experimentally. Three bandwidth values, 0.5, 1.0, and 2.0 Hz, were used to perform peg-in-hole insertion and removal tests. The system performance was assessed by measuring the task completion time and the sum-of-squares of the contact forces and moments applied on the peg. The experimental results indicate significant performance improvement when the bandwidth was increased from 0.5 to 1.0 Hz. No change in performance is shown, however, between the 1.0 and 2.0 Hz cases.>

The authors examine the computed torque control problem for a robot arm with flexible, geared, joint drive systems which are typical in many industrial robots. The standard computed torque algorithm is not directly applicable to this class of manipulators due to the dynamics introduced by the joint drive systems. The proposed approach overcomes this problem by combining a novel computed torque algorithm with simple torque controllers at each joint of the robot. The control scheme is applied to a seven degree-of-freedom industrial manipulator, and the system performance in standard tasks is evaluated using both dynamic simulation and actual experiments. The results show that the proposed controller leads to improved tracking performance over a conventional PD (proportional plus derivative) controller.>