This book puts forward the concept of a virtual equivalent system (VES) based on theoretical analysis and simulation results. The new concept will facilitate the development of a unified framework for analyzing the stability and convergence of self-tuning control (STC) systems, and potentially, of all adaptive control systems. The book then shows that a time-varying STC system can be converted into a time-invariant system using a certain nonlinear compensation signal, which reduces the complexity and difficulty of stability and convergence analysis. In closing, the VES concept and methodology are used to assess the stability of multiple model adaptive control (MMAC) systems and T-S model-based fuzzy control systems.

Weicun ZHANG is an associate professor at the School of Automation and Electrical Engineering, University of Science and Technology Beijing. He obtained his Ph.D. degree in control theory and applications from Tsinghua University in 1993. His research interest covers adaptive control, multiple model adaptive control, intelligent control, and their applications, etc.

Qing Li is a professor at the School of Automation and Electrical Engineering, University of Science and Technology Beijing. He obtained his Ph.D. degree in control theory and applications from University of Science and Technology Beijing in 2000. His research interest covers intelligent control, navigation, path planning and their applications, etc