[25 Years Ago]

The autonomous control technique described here allows a robot to generate its own sequence of optimal configurations during calibration. This algorithm attempts to tell the controller "where to go" in its configuration space such that the estimates of kinematic link parameters converge faster than for any other sequence of positions. It assumes that there is an external measuring device that can sense the position (but not necessarily the orientation) of a fixed point on the end effector. As the parameters are identified with a recursive estimation routine, a cost function is computed which embodies the covariance matrix of the parameter error estimates. The rate of decrease of this function is then maximized over all possible directions in the joint tangent space so that the next position chosen is automatically in the most "exciting" direction for the estimator. The technique is tested in a simple simulation and formulated for application to practical 6R robots. Using the technique, a robot could "calibrate itself" from an arbitrary initial condition without any operator input or supervision.