Nonlinear tracking control design of a robot arm using robust right coprime factorization and sliding mode approaches

In this paper, a nonlinear tracking control of a robot arm in the presence of uncertainties is proposed by using robust right coprime factorization and sliding mode approaches. In general, there exist unknown modeling errors in measuring structural parameters of the robot arm and external disturbances in real situations. In the present control system design, the effect of the modeling errors and disturbance on the system performance is considered to be uncertainties of the robot arm dynamics. Considering the uncertainties, a nonlinear tracking control to a robot arm in the presence of unknown uncertainties is studied. That is, firstly a nonlinear robust stable control system is designed based on robust right coprime factorization approach. Secondly, a tracking system using sliding mode control based on the improved exponential trending law is proposed to improve tracking performance. Finally, the effectiveness of the designed system is confirmed by simulation results.