Бейханов Р.М.
AUTOMATIC INSTALLATION AND ADAPTATION *
Аннотация:
there is annalistic of automatic installation and adaptation
Ключевые слова:
automatic, installation, adaptation
The natural direction of development of commercial PID regulators is the development of methods to reduce the cost of human labor for their installation, configuration and maintenance. In spite of the fact that many methods of automatic tuning and adaptation of PID regulators used at present, were developed in the 1960s, in industrial controllers, adaptive technology began to be used only from the mid-1980s. This is due to the technical complexity of implementing adaptive algorithms on the element base, which existed before the appearance of microcontrollers. Setup can be done manually or automatically, without human intervention (autotune). Autotune can be performed fully automatically and "on demand" when the person is the initiator of the setting. Fully automatic tuning can be initiated when a predetermined condition occurs, for example, when the load changes, when external influences change, when the control error changes, or continuously in time. Automatic configuration initiated without human intervention is called adaptation. An example of adaptation is autotune when the number of eggs in an incubator changes or the load on the motor shaft. Sometimes the term "adaptation" is interpreted more broadly as the adaptation of a regulator to a real object at the stage of commissioning a system. A variation of adaptation is the open control of the controller parameters (table auto-tuning), when the previously found controller parameters for different operating conditions of the system are entered into a table from which they are extracted when the conditions under which the adaptation is initiated occur. Adaptation is in principle a slow process, so it cannot be considered as continuous monitoring of the controller's parameters for the changing parameters of the object. Note that regulators that are configured in automatic mode are more often configured worse than those configured in manual mode [O'Dwyer]. This is explained by a philosophical argument that a computer cannot perform complex and poorly formalized tasks better than a person. At the moment, there are no simple, reliable and generally accepted methods of automatic configuration. All types of automatic settings use three fundamentally important steps: identification, calculation of controller parameters, setting [Iserman]. Often the final stage includes the adjustment phase (final tuning optimization). Optimization of settings is necessary due to the fact that the methods for calculating controller parameters by the formulas are simplified, do not take into account the nonlinearity of the object, in particular, the always-present non-linearity of the "constraint" type, and the identification of the parameters of the object is performed with some error. The adjustment of the regulator can be a search engine (without identifying the object, by finding the optimal parameters) and non-searching (with identification). Search identification is usually based on rules (see the section “Manual adjustment based on rules”) or on iterative algorithms for finding the minimum of a criterial function. The most common search for optimal parameters using the gradient search method. To do this, find the derivatives of the criterial function by the parameters of the PID controller, which are components of the gradient vector. Next, change the parameters in accordance with the direction of the gradient. It is important to emphasize that despite the presence of an “automatic” adjustment, the controller may not provide the required quality of regulation for reasons beyond the quality of the algorithms embedded in it. For example, a control object may be poorly designed (dependent control loops, high latency, high object order); the object may be non-linear; the sensors may be located in the wrong place where it is necessary and have poor contact with the object, the level of interference in the measurement channel may be unacceptably large; the resolution of the sensor may not be high enough; the source of input to the object may have too much inertia or hysteresis; there may also be errors in the installation of the system, poor grounding, wire breaks, etc. Therefore, before starting the automatic configuration, you need to make sure that these problems are absent. For example, if due to the wear of the mechanical system an unexpected hysteresis appeared and the system is therefore in oscillation mode, adjusting the controller may not give the desired result until the cause of the problem has been eliminated
Номер журнала Вестник науки №5 (14) том 4
Ссылка для цитирования:
Бейханов Р.М. AUTOMATIC INSTALLATION AND ADAPTATION // Вестник науки №5 (14) том 4. С. 450 - 453. 2019 г. ISSN 2712-8849 // Электронный ресурс: https://www.вестник-науки.рф/article/1447 (дата обращения: 23.04.2024 г.)
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