Control of nonlinear plants with a guarantee for the controlled signal to stay within a given set under disturbances and high-frequency measurement noises

Abstract

A new control algorithm for nonlinear plants is proposed, ensuring the controlled variable stays within a given set under conditions of parametric uncertainties, external disturbances and high-frequency noises in measurements. The problem is solved in two stages. In the first stage, a low-pass filter is applied to eliminate high-frequency components in the measured controlled signal. In the second stage, a coordinate transformation represents the initial problem with given restrictions as an input-state stability analysis problem of a new system without constraints. An output feedback algorithm has been developed for uncertain nonlinear systems under conditions of parametric uncertainties, external disturbances, and high-frequency noise in measurements. Simulations in MATLAB/Simulink are given. The simulation results show the efficiency of the proposed algorithm. The proposed algorithm can effectively solve control problems for power systems or electromechanical systems in the presence of measurement noises.

Keywords

• nonlinear system
• disturbance
• noise
• the change of coordinates
• stability
• robust control