Self tuning regulator

The architecture of the self-tuning regulator is shown in Fig. 7.99. It is similar to that of the Model Reference Adaptive Controller in that it also consists basically of two loops. The inner loop contains the process and a normal linear feedback controller. The outer loop is used to adjust the parameters of the feedback controller and comprises a recursive parameter estimator and an adjustment mechanism. 

Supervisory control and data acquisition Solid-state relay Self-tuning regulator Temperature recorder controller Transistor-transistor logic Zero order hold element... 

Borisson, U. and Wittenmark, B., "An Industrial Application of a Self-Tuning Regulator," 4th IFAC Conference on Digital Computer Applications to Process Control, Zurich, Switzerland, 1974. 

Wittenmark, B. "A Self-Tuning Regulator", 1973, Technical Report 7311, Division of Automatic Control, Lund, Inst, of Tech., Lund, Sweden. 

If the process is not known well, we need to evaluate the objective function on-line (while the process is operating) using the values of the controlled output. Then the adaptation mechanism will change the controller parameters in such a way as to optimize (maximize or minimize) the value of the objective function (criterion). In the following two examples we examine the logic of two special self-adaptive control systems model reference adaptive control (MRAC) and self-tuning regulators (STRs). 

VII.54 Derive the general expressions for the design of a self-tuning regulator which is to be used for the control of the following second-order process ... 

Self-adaptive control, 436-38, 662-67 Self-regulating systems, 7, 34, 180 Self-tuning regulator, 437-38, 662-67 references, 447, 673 Serial transmission, digital signals, 561 Servo problem (see Feedback control)... 

Consider the block diagram of Figure 22.5. It represents the structure of a self-tuning regulator, which constitutes another way of adjusting the parameters of a controller. 

Discuss the logic of model-reference adaptive control and self-tuning regulators. Find the similarities and differences between the two configurations. 

Show qualitatively that the structure of a self-tuning regulator can be derived from that of a model-reference adaptive control if the parameter estimation is done by updating the reference model. 

The self-tuning regulator was originally proposed by Kalman, who built a special-purpose computer to implement it. Subsequently, the STR received a lot of attention because it is flexible and easy to understand and implement it. In Section 31.2 the reader can find a very simplistic quantification of STR. The work of Astrdm and his coworkers represents the evolution of STR development, and the following two references would be very instructive for the motivated reader ... 

On Self-Tuning Regulators, by K. J. Astrom and B. Wittenmark, Automa-tica, 9,185 (1973). 

Self-Tuning Regulators—Design Principles and Applications, by K. J. Astrdm. This paper can be found in Ref. 19. 

In References for Part VII the reader can find additional entries on the applications of self-tuning regulators. A very good source for the problems and design of inferential control systems is the work of C. Brosilow and his coworkers ... 

Example 31.3 Designing a Self-Tuning Regulator for a Second-Order Process... 

The present example describes how a digital controller can adapt its parameters automatically on-line, during process operation. The resulting system can be called a self-tuning regulator. Assume that a poorly known process can be approximated by a second order model ... 

Application of Self-Tuning Regulator to the Control of Chemical Processes, by A. J. Morris, T. P. Fenton, andY. Nazer, in Digital Computer Applications to Process Control, H. R. VanNauta Lemke and H. B. Verbruggen (eds.), 5th IFAC/IFIP International Conference, The Hague (1977). 

Implicit in such a self-tuning regulator model is the assumption that afferent inputs may up- or down-regulate the RCPG by inducing synaptic potentiation or depression of neural transmission. Respiratory short- and long-term potentiation have been variously reported as indicated above. The possibility of synaptic depression was recently demonstrated in the nucleus tractus solitarius of the medulla (Zhou... 

Astrom, KJ. and Wittenmark, B. 1975. On self-tuning regulators. Automatica 9 185. 

Fig. 5.8 Schematic of a robust adaptive control scheme (a) Indirect adaptive control paradigm (b) diagram of robust self-tuning regulator. Reprinted from [Pang et al. (2008c)] with permission from IEEE, Copyright 2008.

To design a self-tuning regulator, we first choose a desired model for the closed-loop system ... 

Self-tuning regulator models, in respiratory control system structure, 11-12 Sellick, P.M., 63-9 Semantic compaction language representation methods, 72-3... 

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