Precise Disturbance Modeling for Improvement of Positioning Performance

Abstract

This paper presents a modeling methodology for unknown disturbances in mechatronics systems, based on a disturbance estimation using an iterative learning process. In the disturbance modeling, the nonlinear friction is especially handled as the disturbance in mechanisms, which mainly deteriorates the trajectory control performance. The friction can be mathematically modeled by using the learned estimation data, as a function of displacement, velocity, acceleration, and jerk of the actuator. This model has a distinguished feature that the friction compensation can be achieved with a generalization capability for different conditions. The proposed positioning control approach with the disturbance modeling and compensation has been verified by experiments using a table drive system on machine stand.