Experimental identification of inertial parameters of a PUMA 560 industrial robot

The estimation of robot inertial parameters constitutes an issue of vital importance not only for those dynamical aspects related to control but also for movement simulation. Indeed, in such complex mechanical systems as robots are, precise information about those parameters is rarely available, what makes it necessary to proceed to their experimental determination. Among the various procedures that have been proposed until now to approach this problem, a differential robot model, which is based on the inverse dynamics equations, will be considered instead of an integral model based on the energy equations. A complete dynamic robot model will be used, including the effect of the rotors. Starting from the Gibbs-Appell equations, the inverse dynamics equations will be obtained in a suitable form for parameter identification. In order to diminish the influence of the measurement errors on the determination of the inertial parameters, the trajectory used for the experimental identification should be designed in such a way that the observation matrix presents some appropriate characteristics, fundamentally a low condition number and also a low equilibrium factor. Experimental results corresponding to a PUMA industrial robot are provided.