Robust system control with fuzzy logic fusion: Stability analysis and controller synthesis

Abstract

For most practical dynamic processes, non-linearity and uncertainty are two major factors which trouble the control system design. Approaches embedding fuzzy-logic-based inference mechanism have paved an alternative way to tackle these problems. In this paper, a T-S type global model of a non-linear process which engages the format suitable for robust system analysis and synthesis is presented, and a hybrid process control structure recommended. Based on the assumption that the control system developed hires the same fuzzy logic inference mechanism for controller fusion, a stability condition for the fuzzy-logic-based control system has been achieved and an approach of robust stability synthesis via linear matrix inequalities (LMI) discussed. The simulation results of a design example (an end milling process control) shows that robust stability and satisfactory performance have been reached.