A Method for Online Identification of Oscillatory Type Machine Model Including Nonlinear Friction

Abstract

The linear actuator driven by a ball screw mechanism is widely used in the machine tools, since it can raise the machine speed higher. For the purpose of the stability in continuous path control of this type mechanism, it is important to identify the machine parameters, such as inertia, spring stiffness and dominant nonlinear friction. In this paper, we present a practical method to identify the nonlinear parameters of the table driven by a ball screw mechanism. The mechanical parameters are identified by using the steepest descent method with a dead band. This paper confirms effect of the proposed method from the results of the experimentation.