OPERATOR-BASED ROBUST CONTROL FOR NONLINEAR PLANTS WITH UNCERTAIN NON-SYMMETRIC BACKLASH

This paper presents an operator-based robust nonlinear control method for nonlinear plants with uncertain non-symmetric backlash. The control design is achieved by introducing operator-based robust right coprime factorization. In more detail, using an operator-theoretic approach, the uncertain non-symmetric backlash is described as a generalized Lipschitz operator and a bounded parasitic term. Since the generalized Lipschitz operator is unknown, a new robust condition using robust right coprime factorization is proposed to guarantee robust stability of the controlled plant with the uncertain backlash. As a result, based on the proposed robust condition, a stabilized plant is obtained. For eliminating the effect from the parasitic term to ensure the output tracking performance, a nonlinear tracking controller is designed. Simulation results are presented to validate the effectiveness of the proposed control design method.