Influence of inertial parameters on the positional accuracy of a robot

The need of accuracy in the knowledge of the values of inertial parameters of a robot for implementing a computed torque control method is appraised through a simulation analysis which investigates the influence of different inertial parameters on the positional accuracy. Various simulation runs have been performed on the model of a PUMA 562 manipulator with computed torque control, some deviations of the inertial parameter values being deliberately introduced in the implemented control law. Simulation results show that the parameters related to static moments (gravity effects) and to the diagonal terms of the inertia matrix are the most significant. Fortunately those parameters can be estimated with good accuracy by an external identification procedure which is described briefly.<>