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Створити нову тему Відповісти  [ 17 повідомлень ]  На сторінку Поперед.  1, 2
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 Тема повідомлення: A practical tuning methodology for event-based PI control
ПовідомленняДодано: 24 вересня 2014, 10:46 
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Викладач

З нами з: 29 листопада 2013, 17:11
Повідомлення: 4992
A practical tuning methodology for event-based PI control
Journal of Process Control 24 (2014) 278–295
link
Цитата:
This paper is focused on the tuning of an event-based PI controller for first-order plus time delay systems (FOPTD). In this work, a novel design and combination of a controller and event generator with an easy-to-use tuning methodology is presented. The event generator combines the Smith predictor structure with the symmetric send-on-delta (SSOD) sampling scheme to compensate the delay and trigger the events. The controller has an adaptive structure with the purpose of improving the set-point tracking and guaranteeing stability under conditions of uncertainty. The approach is focused on FOPTD systems but can be easily extended to higher order systems. Stability and robustness analyses are conducted, and the experimental results verify the effectiveness of the approach.


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 Тема повідомлення: Real-Time Optimization Framework for the Iterative Controll
ПовідомленняДодано: 25 січня 2015, 17:42 
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З нами з: 29 листопада 2013, 17:11
Повідомлення: 4992
A Real-Time Optimization Framework for the Iterative Controller Tuning Problem
http://www.mdpi.com/2227-9717/1/2/203
Цитата:
Abstract: We investigate the general iterative controller tuning (ICT) problem, where the task is to find a set of controller parameters that optimize some user-defined performance metric when the same control task is to be carried out repeatedly. Following a repeatability assumption on the system, we show that the ICT problem may be formulated as a real-time optimization (RTO) problem, thus allowing for the ICT problem to be solved in the RTO framework, which is both very flexible and comes with strong theoretical guarantees. In particular, we propose the use of a recently released RTO solver and outline a simple procedure for how this solver may be configured to solve ICT problems. The effectiveness of the proposed method is illustrated by successfully applying it to four case studies—two experimental and two simulated—that cover the tuning of model-predictive, general fixed-order and PID controllers, as well as a system of controllers working in parallel.


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 Тема повідомлення: Rasmussen H. Automatic tuning of PID-regulators
ПовідомленняДодано: 25 січня 2015, 18:41 
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З нами з: 29 листопада 2013, 17:11
Повідомлення: 4992
Rasmussen H. Automatic tuning of PID-regulators
http://ece.ut.ac.ir/classpages/S84/Mech ... ID_REG.pdf
This text summarizes digital PID control and methods for automatic tuning based on relay feedback. The text is intended for use as a part of a graduate course in Adaptive Control and the topics are selected from the references with this in mind.
Цитата:
Many process control problems can be adequately and routinely solved by conventional PID-control strategies. The overriding reason that the PID controller is so widely accepted is its simple structure which has proved to be very robust with regard to many commonly met process control problems as for instance disturbances and nonlinearities. Tuning of the PID settings is quite a subjective procedure, relying heavily on the knowledge and skill of the control engineer or even plant operator. Although tuning guidelines are available, the process of controller tuning can still be time consuming with the result that many plant control loops are often poorly tuned and full potential of the control system is not achieved. One way of deriving a self-tuning control law with the structure of a PID controller is to approximate the system with a parameterized model of order  or  and calculate the controller coefficients using a design method as e.g. pole placement, generalized predictive control or LQG.
These methods are easily extended to a higher order with possibility of better control performance. They require a fair amount of a priori knowledge as for instance sampling period, dead time, model order, and desired response time. This knowledge may either be given by a skilled engineer or may be acquired automatically by some kind of experimentation. The latter alternative is preferable, not nly to simplify the task of the operator, but also for the sake of robustness.
A key method for auto-tuning (A° stro¨m and Ha¨gglund 1988) is to use relay feedback.
Processes with the dynamics typically encountered in process control will then exhibit limit cycle oscillations and the auto tuner identifies one point on the Nyquist curve of the process from the experiment. When the operator decides to tune the controller, he simply presses a button starting a relay experiment. The relay feedback causes the process to oscillate with a controlled amplitude. The frequency of the limit cycle is approximately the ultimate frequency where the process has a phase lag of The ratio of the amplitude of limit cycle and the relay amplitude is approximately the process gain at that frequency. Thus a point on the Nyquist curve of the open loop dynamics close to the ultimate point is determined. A reasonable PID controller based on this point may then be calculated.


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 Тема повідомлення: Адаптивные регуляторы нового поколения
ПовідомленняДодано: 25 січня 2015, 18:49 
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З нами з: 29 листопада 2013, 17:11
Повідомлення: 4992
Адаптивные регуляторы нового поколения (частотные адаптивные регуляторы)
http://www.adaplab.ru/
http://www.adaplab.ru/publications


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 Тема повідомлення: Адаптивные автоматически настраивающиеся ПИД-регуляторы
ПовідомленняДодано: 25 січня 2015, 19:16 
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З нами з: 29 листопада 2013, 17:11
Повідомлення: 4992
Шубладзе А.М., Гуляев С.В., Шубладзе А.А. Адаптивные автоматически настраивающиеся ПИД-регуляторы // Промышленные АСУ и контроллеры. 2003. № 6.
http://avtprom.ru/sites/default/files/32-38_0.pdf
на примере Омрона


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 Тема повідомлення: Autotuning of a PID-controller
ПовідомленняДодано: 25 січня 2015, 19:27 
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З нами з: 29 листопада 2013, 17:11
Повідомлення: 4992
Autotuning of a PID-controller
Camilla Andersson, Mirjam Lindberg
http://www.control.lth.se/documents/2004/5728.pdf


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 Тема повідомлення: A remote laboratory on PID autotuning
ПовідомленняДодано: 25 січня 2015, 19:37 
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Викладач

З нами з: 29 листопада 2013, 17:11
Повідомлення: 4992
A remote laboratory on PID autotuning
http://www.nt.ntnu.no/users/skoge/prost ... s/0532.pdf
Abstract: This manuscript presents a remote, web-enabled laboratory devoted to PID autotuning—a subject of significant importance from both the theoretical and the application-oriented point of view, but seldom available in remote laboratories. In detail, the manuscript presents two PI/PID autotuning experiments on physical control systems; the experiments are accessible by means of a browser, and the code is available as free software. Some pedagogical issues are also briefly discussed.
Цитата:
A huge number of automatic control experiments is nowadays offered by remote laboratories, as witnessed by works such as Aktan et al. (1996); Valera et al. (2005); Aliane et al. (2006), and many others; such resources are nowadays very important for control education at all levels (Dormido Bencomo, 2004).
However, a very small minority of experiments available from remote laboratories is relative to the domain of autotuning, a
notable exception being e.g. Balda et al. (2004).
This is a lack to be filled, for at least three reasons. First, there is a vast literature on autotuning, with particular reference to the PI/PID controller structure (A° stro¨m and Ha¨gglund, 1995; Leva et al., 2002; O’Dwyer, 2003). When a subject is so extensively
investigated, also the availability of well designed laboratories on that subject becomes a necessity, both for research and for education purposes. Second, autotuning capabilities are now included in many industrial regulators, see e.g. Li et al. (february 2006), and users tend more and more to rely on them. This fact is of particular importance in process control, for example, where a systematic application of autotuning to the hundreds of low- or mid- level loops involved in the typical plant allows to shorten commissioning and maintenance time significantly, and also to focus attention on the top-level plant controls. Also in motion control, to quote a somehow complementary field with respect to process control, autotuning yields significant benefits, as witnessed by the numerous products that nowadays offer such a feature. In synthesis, then, mastering not only the practical the use, but also (which is even more important) the
theory of operation of an autotuner is important for the control engineer—and is not as easy a task as one may think at a first glance, as will appear later on. Third, constructing an autotuner is a challenging and fascinating activity, and probably the core of the competencies to induce when educating engineers. Turning a method to (auto)tune a regulator from the form it takes in the scientific literature to that of a complete procedure capable of running autonomously on a control computer involves a large amount of design choices, which can be taken consciously only if the designer possesses an adequate mix of control-theoretical and software engineering capabilities.


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Створити нову тему Відповісти  [ 17 повідомлень ]  На сторінку Поперед.  1, 2

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