Tuning of a multivariable controller for a robot manipulator

A linear multivariable PI-controller that can be designed based on step responses is presented. Choice of fine tuning parameters for the controller is discussed and solved as an optimization problem. Optimization results suggest that fine tuning can be chosen very simply. The problem of performing step response experiments with manipulators is brought up. Because of the unstability of the open loop system, step responses are best to carry out with manipulator simulators. Also a suggestion of how to deal with the positional variances of the manipulator dynamics is presented.