Abstract
Non-linearity and uncertainty are two major issues which trouble the control system design. During past decades, many non-linear control approaches and robust control approaches have been developed to tackle these issues. This paper discusses an alternative approach for designing a control system for a dynamic process with some kind of non-linearity and uncertainties. This approach embeds fuzzy-logic-based inference mechanism into a linear robust control framework to achieve a robust property within the whole operating region of a dynamic process. In this paper, firstly, a T-S type global model of a non-linear process which engages the format suitable for robust system analysis and synthesis is presented. 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) show that robust stability and satisfactory performance have been reached.
