A Position-Based Friction Error Model and Its Application to Parameter Identification

Most existing methods rely on the torque information of a servo drive to predict the tracking error caused by the friction force (friction error), but the torque information is not available in certain systems. This paper proposes a position-based modeling method for the friction error. Two examples are given to verify the practicality of the proposed friction error model on the systems when torque information is not available. The experimental results show that the proposed method can predict the friction error accurately and the proposed online parameter identification method exhibits better performance. The proposed position-based friction error model can also be easily applied to commercial CNC systems because only the position information is required.