Optimization of performance criteria with bounded joint velocities for robots with one degree of redundancy

Most kinematic control schemes for robots with redundant joints determine the joint motions for a desired end-effector trajectory such that a performance criterion is optimized. When the robot is in motion, it may reach a configuration in which the joint velocities required to optimize a performance criterion, while following a desired end-effector trajectory, may be extremely high. This problem is referred to as an algorithmic singularity. The control scheme presented in this paper avoids high joint velocities by compromising optimization of the performance criterion in the neighborhood of an algorithmic singularity. This scheme does not require the pseudoinverse of the Jacobian and thus, it is computationally efficient and well suited for real-time implementation. Unlike other control schemes, the robot is not required to be an optimum configuration at the starting point. The application of this scheme to a seven-degree-of-freedom manipulator at the Center for Engineering Systems Advanced Research (CESAR) is described. 11 refs., 6 figs., 1 tab.