Self-Tuning Control Systems: A Review of Developments

Background: Technical Review Of Self-Tuning Control

This chapter on ‘Self-tuning Control Systems: A Review of Developments’ aims to inform the reader of the major developments and historical landmarks in the topic up to the present day. The earliest reference dates back to the first International Symposium on Self-Adaptive Flight Control in 1959 which was held at what is now the Wright-Patterson Air Force Base, Dayton, Ohio, USA (Gregory, 1959), where the concept of ‘self learning’ control was first proposed. However, due to the lack of available technology at that time, in terms of reliable computer hardware and software, it was a decade before this concept was to re-emerge. In fact it re-emerged under the name of self-tuning control (STC) in the 1970s and was notably driven in those earlier years by Kalman (1960), Peterka (1970), and Astrom and Wittenmark (1973), who are now recognized as the early pioneers in this field. The major breakthrough by Astrom and Wittenmark (1973) with the optimal d-step ahead minimum variance (MV) self-tuning regulator/controller (STR)/STC in which convergence was proved for the simplest case was perhaps the first landmark which led to a positive resurgence and increased interest in the subject. This was followed in 1975 by the development due to Clarke and Gawthrop (1975) with the generalised minimum variance (GMV) STC in which constraints on control effort could be implemented to achieve a realizable control system. This led naturally to the incremental forms of MV and GMV STC, in which inherent integral action is automatically achieved.