ABSTRACT
This chapter deals with variable-structure schemes and discusses the reduced order schemes and adaptive predictive control systems. In variable-structure systems (VSS) changes can occur in the system structure during the transient periods, unlike conventional control systems. Variable-structure controllers are characterized by a discontinuous control action which changes structure upon reaching a set of switching surfaces. The chapter provides fuzzy logic adaptive control methods, applicable to very complex processes which have been difficult to control automatically. It considers adaptation using the internal model principle and also discusses adaptive control by inverse modeling. Adaptive predictive control systems (APCS) have been developed according to a methodology which is different from that of model reference adaptive control (MRAC) systems and self-tuning regulators (STRs). J. M. Martin-Sanchez works out the proof for global stability of APCS for discrete linear processes with pure time delays in the presence of bounded noise and unmeasured disturbances.
