Friction Compensation Based Coprime Factorization for Nonlinear Systems

Friction is a powerful nonlinearity with discontinuity and uncertainty, and it is a significant obstacle to achieving high precision in control systems. In recent years, with the increasing demand for medical robots, high-precision positioning of robot arms is required. Since friction is an obstacle to high-precision control, friction compensation is essential. In this study, we propose a new approximation method for friction compensation and a method for compensating for uncertain friction based on coprime factorization. By using these two methods, we prove that the positioning error of the system is smaller than a finite user-set value λ.