Displacements that null forces

Experimental results indicate that the inner product defined by stiffness does in fact provide the correct force-error nulling directions along which to move a robotic end-effector. These directions, which are defined as the twists of compliance, form the (K)-orthogonal complement to the twists of freedom of a partially constrained gripper (where the matrix (K) describes the stiffness of the robot and not its task). This implementation of kinestatic control is accomplished via the synthesis of two scalar gains to effect the six-dimensional, simultaneous control of force and displacement.<<ETX>>