Chapter 12 – Identification of the dynamic parameters

This chapter addresses the problem of identification of the dynamic parameters of robots. It proposes several methods that are linear in these parameters and have the same set of base dynamic parameters. Most advanced control schemes formulated in the recent literature for robots require dynamic models. The precision, performance, stability, and robustness of these schemes depend, to a large extent, on the accuracy of the parameters that describe the dynamic model. Adaptive and robust schemes can tolerate some errors in the dynamic parameters, while other schemes aimed at achieving perfect feedback linearization, such as the computed torque technique, assume precise knowledge of the dynamic parameters. In view of this, a priori precise determination of the dynamic parameters is useful to most schemes and is crucial to some others. Furthermore, these values are necessary to simulate the dynamic equations. Accurate values of the dynamic parameters are typically unknown, even to the robot manufacturers. This chapter also presents different criteria to measure the excitation of a given trajectory pointing out that the dynamic and filtered dynamic models are basically more exciting than the energy and power models.