Dynamic performance as a criterion for redundant manipulator control

Kinematically redundant manipulators have been proven to offer certain advantages over more heavily constrained systems. One such advantage is the extra degrees-of-freedom can be used for other tasks such as maintaining a posture which affords higher acceleration capability in the direction of the desired motion. However certain issues arise when considering the control of these mechanisms due to the lack of invertability of the rectangular Jacobian matrix. Here this issue is addressed by augmenting the rectangular Jacobian with a characterization of the null space motions. This approach allows for a gradient-based control scheme, based upon the dynamic capability equations, to increase or maintain the local performance capability of a manipulator as it performs some task. Simulation results of the application of this control scheme to a six degree-of-freedom (DOF) planar manipulator are given to illustrate the control's advantages on a highly redundant system.