A parameter identification method of horizontal robot arms

Abstract

In order to develop an advanced control system and a simulation system for a robot arm, it is necessary to establish an accurate identification method for a dynamical model. The parameters of the dynamical model of a robot arm consist of the link length, the position of the centre of mass, the mass of the link, viscous damping, and Coulomb friction. However, it is not necessary to estimate these parameters independently because if several combined constants appearing in the equation of motion are obtained, then the control and simulation can be done using only these combined constants. In this paper, first we show that viscous damping and Coulomb friction are obtained by measuring the relation between the current and angular velocity. Then we propose an effective identification method of inertial terms using the mechanical resonance occurring due to the stiffness of the joints.