Назад в библиотеку

---

The study of the dynamics of the system control the technical condition of equipment

Авторы: В. А. Резников, Е. М. Сорокина

Перевод: Сорокина Е.М.

Описание: It is suggested to examine the technical systems of the state, as systems of automatic control, by the formed chart of service of technical service and repair, as a managing device.

Источник: Журнал "Искусственый интеллект"

УДК 658.3

 

V.A. Reznikov, K. M. Sorokina

                 Research of dynamics of control system by the technical state of equipment
                 It is suggested to examine the technical systems of the state, as systems of automatic control, by the formed chart of service of technical service and repair, as a managing device.

Statement of the Problem

The effectiveness of the equipment in the respective estimated using objective or subjective indicators (called performance indicators [1]), which are observed either directly by staff or special technical means. The defects that occur in equipment during its operation, lead to changes in the parameters of efficiency, and as a consequence, the deviation from the values ​​of performance indicators established by the normative and technical documentation. Depending on the magnitude of these deviations are recorded failure of the object or its pre-crash (predotkaznoe) technical condition, and thus determined by the work already accomplished to eliminate the failure or the various preventive maintenance and repairs to prevent the occurrence of failures when the equipment is intended. All these works are carried out service maintenance and repair service (TOR). And, as in the first, that in the second case the problem is actually the TOP service is to eliminate these variations, that is, the "return" performance at the limits of the established tolerances for them.

Consequently, the service can be regarded as the TOP management system technical condition of equipment (SUTS), whose mission is, by definition [2], is to stabilize the performance parameters set at the level prescribed by the normative and technical documentation for the entire period of use of the equipment as intended by purposeful human action (a group of people) and instruments of labor, that is, by the government. Moreover, a feature of this control system is that there are intra-driven variable properties of machines and mechanisms, which maintain the required level ensures efficient use of equipment for other purposes.

At the same time, considering the equipment as a dynamic system (a dynamic object management), in [3] indicated that the failure object to transition from one state to another technical accompanied by a transient whose duration depends on the type of violation and the dynamic properties of the object. It is clear that the dynamic nature of the process is and disaster recovery. Thus, there is reason to study the control system technical condition of equipment, such as the stabilization system, using the methods adopted in control theory.

This paper focuses on the formation of the block diagrams of control of the technical condition of the equipment as a system of automatic stabilization performance at a given level.

 

The structure of the facility maintenance

In accordance with the approach we assume that the object of maintenance is generally described by the transfer function of the form:

                              (1)

where Yt (s) - Output (controlled) process variable object, UT (s) - the control action, provided the technology of the object.

Defects of the object, by definition [4], are the outputs of its own (structural) parameters beyond tolerances established for them. In the framework of the model (1), this means changing the coefficients b0, ..., bm, and a0, ..., an. When a certain character of the change of control action UT (s) specified changes in the coefficients of the model (1), of course, warrant a change as most Yt output variable (s), and its characteristics (eg quality of the transition process), ie, in the end , performance of the object to its destination.

At the same time, we know that the dynamic object described by the transfer function of the general form (1) can be represented as a corresponding block diagram. For example, suppose an object is described by the transfer function

As a result, the necessary transformations, we obtain that this object can be represented as the block diagram shown in Figure 1. Such a structural representation of the mathematical model (2) suggests that in the restored object parameters a0, a1, a2 and a3 "represent" the appropriate functional-structural elements A 0, A 1, A-2 and A-3. In this case, the output values ​​of these parameters outside the specified tolerances on them (ie, defect) can be equated with the refusal of the corresponding functional-structural component. For example, the parameter a3 can be formulated as the following defect: "Refusal of A-3."

 

Such a structural representation of object maintenance (control object, the object of stabilizing the technical conditions) makes it possible to carry out further transformations, which consist of the following.

Each i-th parameter of the object (1) can be written as:

                                                            (3)

where - the nominal value of the i-th parameter (working-state of the Ai); - changes in the i-th parameter, due to the fault element of Ai.

This, in turn, allows us to represent the object of control, in which there are single defects in the form of the block diagram shown in Figure 2, and - the transfer functions of the object at the nominal parameter values.

Figure 2 - Modified block diagram of the control object

           Note also that such structural representation of an object management system controls allow you to explore the technical state of objects of any complexity, if by any mean structural complexity, which is determined by the order of the transfer function [5].

 

The structure of the control device

Figure 3 - Block diagram of the stabilization system in case of failure of i-th element

Every single object with parametric perturbations can be represented as a set of objects. For example, if an object is described by the model (1), for m = 0 we have N = (0, 1, ..., n) objects, which are block diagrams of the form shown in Figure 2. At the same time, the principle of adaptation, in fact, lies in the fact that as a result of self-tuning control parameters of the base is formed by the set of non-adaptive controllers, each of which is intended to stabilize the quality "of his» i-th object (see Figure 3).

On the other hand the service of TOR as some organizational and structural unit of the enterprise, can be represented in a simplified form: Head + repair personnel. The task manager is to determine the technical state of the object and the direction of "appropriate" repairman to eliminate the causes of technical change in the state. The task of each repairman is in immediate removal causes changes in the technical state of the object. Consequently, the language of the concepts adopted in control theory, the service can be regarded as the TOP control unit consisting of a logical block (head) and a set of regulators (repairers), that is, the control device formed on the basis of structural adaptation [8] and has structure shown in Figure 4, where indicated: LB - logical block; S (t) - the set of input variables that contain information about the technical state of the object of control, 1 - identifier, designed to determine the reasons for the refusal of the object (object identity of the failed element), 2 - decision-making unit, 3 - a modifier that produces a control signal switching power supply unit; Pk - k-th control; uik (t) - management of the technical state of the i-th element of the object formed by the k-th controller.