Automation of control and safety of an industrial facility.

Automation of control and safety of an industrial facility.

Prerequisites

A comprehensive safety system for an industrial facility (hereinafter referred to as CSSF) is defined as a complex ergotechnical system designed to protect an industrial facility (PF) from the impact of external and internal sources of security threats, as well as to prevent offenses, the causes and conditions that give rise to them, and the emergence of prerequisites for causing damage to the PF.

The technical condition of the SKOB is understood as a set of SKOB properties subject to change during operation, characterized at a certain point in time by the degree of compliance of the actual values ​​of the indicators and/or qualitative characteristics of the SKOB (hereinafter referred to as parameters) established in the technical documentation for the SKOB.

Automated monitoring and diagnostics (AMD) of the technical condition of the SKOB, the contours of which are outlined within the framework of this article, allows for prompt assessment of the system's operability, and, if there are any faults, to issue a «not suitable» signal.

The procedure for structuring the problem of ACD of the technical condition of the SKOB (see diagram 1) provides for:

• a system-model description of the SKOB as an object of ACD of the technical condition;

• the formation of information support for the organization of ACD of the technical condition of the SKOB;

• the selection of contours for constructing functional subsystems of ACD of the technical condition of the SKOB;

• the selection of criteria and indicators of the effectiveness of ACD of the technical condition of the SKOB.

System-model description of the SKOB

The system-model description of the SKOB consists of forming the appearance of the SKOB subject to the ACD of the technical condition during the maintenance of the system.

The specified description contains, at a minimum, a list of types of technical condition of the SKOB and determines the operational requirements for the ACD means.

Types of technical condition of the SKOB.

Guided by the regulatory technical documents on reliability in technology, it is legitimate to consider three types of technical condition of the SKOB: serviceability, operability and correct functioning in the calculated external conditions.

Serviceability of the SKOB is defined as a state of the system in which it meets all the requirements of the regulatory technical and/or design documentation.

Operability of the SKOB is a state of the system in which the values ​​of all parameters characterizing the ability to perform specified functions meet the requirements of the above documentation.

The transition of the SCBS from one state to another usually occurs due to damage (while maintaining a working condition) or failure (in case of a malfunction).

To determine the type of technical condition of the SCBS, it is necessary to know the assessment of the actual state of the system and the requirements of the regulations for the technical maintenance of the SCBS, characterizing the serviceability, operability and correct functioning of the SCBS.

The task of assessing the technical condition of the SKOB is solved on the basis of the analysis of the results of the ACD obtained during the technical maintenance of the SKOB, during which the quality of the system's operation is restored.

Technical control of the SKOB consists of measuring the actual values ​​of the parameters characterizing the technical condition of the SKOB at the time of observation, and comparing these values ​​with the data contained in the regulations for the technical maintenance of the SKOB.

Technical diagnostics of the SCBS involves checking the serviceability, operability and correct functioning of the SCBS, and in the event of malfunctions, searching for the locations of system failures.

Detection of defects that cause the specified failures is achieved using an automated failure analysis subsystem.

It is assumed that the technical condition of the system can be determined in terms of the entire set of SCBS parameters that describe the behavior of the system at a given point in time.

Forecasting the technical condition of the SKOB at a given advance point in time is possible based on processing the results of technical diagnostics of the SKOB.

Diagram 1. Operational diagram of structuring the problem of ACD of the technical condition of the SKOB

Requirements for ACD tools.

In accordance with the regulatory technical documents of the State System for Ensuring the Uniformity of Measurements, the means of the AKD of the technical condition of the SKOB must correspond to the modern technical level of domestic and foreign instrument making and ensure:

• compliance with the requirements for the automation of technical control and diagnostics processes, the method and type of indication (registration) of control results; • compatibility in parameters with the SKOB as a whole and all functional subsystems included in it;

• the ability to measure (technical diagnostics) the standardized characteristics of the SKOB with the required accuracy and reliability;

• resistance to mechanical, climatic and other external influences under the operating conditions of the SKOB, including resistance to unauthorized actions;

• requirements for self-verification and verification of metrological characteristics. In addition, the ACD tools must meet the requirements for ensuring the safety of working with them, ergonomic indicators, readiness time, type and volume of operational documentation, and the personnel working with the specified tools must have skills in the technique of conducting and fully using the results of ACD of the technical condition of the SKOB.

Information support for the organization of ACD of the technical condition of the SKOB

The basis of this support is the lists of controlled parameters of the SKOB and the means of automation of the processes of control and diagnostics of the SKOB.

Controlled parameters of the SKOB.

The selection of the minimum required number of controlled parameters of the SKOB, carrying sufficient information about the state of the SKOB at any given time, is determined by the following factors:

• firstly, the technical documentation for the SKOB contains a list of controlled “delivery parameters” (established by the SKOB developer), which must be checked in order to maintain the SKOB in working condition when used for its intended purpose;

• secondly, when monitoring (measuring) electrical and other parameters of the SKOB that are not provided for in the technical documentation, the selection of parameters is carried out within the framework of the use by the SKOB service personnel of the methodology and mathematical apparatus that takes into account the specifics of the tasks of the ACD and the properties of the object of control.

When selecting the monitored parameters of the SKOB, the following practical considerations are also taken into account:

• parameters that have a mutual functional or correlation relationship should be excluded from consideration;

• operating parameters for which tolerances are established, the deviation from which is a manifestation of obvious defects, may, as a rule, have a low diagnostic resolution;

• parameters selected during the analysis of the causes of failures must have the maximum diagnostic resolution, which allows for the detection of hidden defects using non-destructive testing methods.

Means of automation of control and diagnostic processes.

To implement the ACD of the technical condition of the SCOB, in general, organizational, technical, informational, methodological, mathematical, software, linguistic and analytical support is required, the composition of which is given in the table.

Table of ACD Support Tools

Contours of constructing functional subsystems of the ACD of the technical condition of the SKOB

In the context of the above, it is logical to consider as possible options for functional subsystems of the ACD of the technical condition of the SKOB:

• automated subsystem for monitoring and diagnosing the technical condition of the SKOB (hereinafter — APCD);

• automated subsystem for analyzing the failures of the SKOB (hereinafter referred to as APAO). The preferred options for constructing the APKO and APAO from among the alternatives for software are subsystems that provide the established values ​​of the partial efficiency criteria.

Structural diagram of constructing the APKO.

In practice, the implementation of the AKD of the technical condition of the SKOB is, in principle, feasible within the framework of several options for solving the problem.

In methodological terms, it is possible to limit ourselves, without violating the generality of the reasoning, to considering only one of these options — the APCD with technical means of the AKD built into the structure of the SKOB, ensuring the implementation of non-destructive technical testing of the SKOB (meaning tolerance and measuring (quantitative) testing).

A version of the enlarged structural diagram of the construction of the APCD is shown in diagram 2.

The diagram includes the following components:

• a measuring device that ensures the determination of analog values ​​of the controlled parameters of the SKOB for a given point in time and the presentation of the results in digital form;

• an informational device that carries out joint processing of the available measurement and a priori information on the parameters of the SKOB for the purpose of individual forecasting of the assessment of the technical condition of the system and the formation on its basis of recommended measures of influence on the corresponding functional subsystems of the SKOB;

Diagram 2. Large-scale structural diagram of the built-in APCS:

1 — a set of physical analog signals of the FP;

2 — stimulating signals (if necessary);

3 — the moment of diagnosis;

4 — a priori information on the FP;

5 — measuring information on the FP, accumulated by a given moment of diagnosis;

6 — the given state of the FP for the moment of diagnosis;

7 — assessment of the predicted state of the FP;

8 — recommended measures of influence on the FP;

9 — the level of expenses for managing diagnostic processes;

10 — the target function, depending on the nature and characteristics of the problem being solved;

11 — recommendations for the technical maintenance of the SCBS of the measures of influence on the corresponding functional subsystems of the SCBS;

• a technological device that implements mathematical models for managing the state of each controlled functional subsystem, which allows one or another optimal decision to be made.

Measuring, informational and technological devices of the APCS should be universal, easily adaptable to various types of functional subsystems of the SKOB.

They should not only indicate (with an accuracy of a removable assembly unit) the location of the malfunction, but also issue the necessary recommendations for maintenance based on the results of diagnostics, while simultaneously reducing labor costs for maintenance to a minimum.

The task is to create algorithms for analyzing accumulated information for electronic computing equipment included in the APCD, as well as algorithms for analyzing the current and predicted state of the SKOB, which allows, as experience in operating a specific SKOB is accumulated, either to reduce or increase the tolerances for the operating characteristics of the specified system.

Structural diagram of the construction of the APAO.

The automated subsystem for analyzing failures of the SKOB is defined as a set of methods and means for analyzing failures, as well as methods for processing diagnostic information to form measures to prevent failures of the SKOB.

The specified subsystem implements diagnostic methods based on the development of:

• a special qualitative and quantitative model description that allows establishing a correspondence between failures of removable assembly units of the SKOB functional subsystems and the diagnostic features accompanying them;

• rules and procedures for the implementation of the primary analysis of failed removable assembly units for the purpose of their localization (dismantling) and subsequent replacement with conditioned ones. In-depth physical and technical analysis of the causes of failures of removable assembly units (RAU) is, in principle, possible only after their opening (disassembly).

A version of the enlarged structural diagram of the construction of the APAO is shown in diagram 3. This diagram includes the following components:

• a device for searching (diagnosing) a failed RAU, ensuring verification (confirmation) of the presence of a failure detected by the APCD;

• a device for assessing the reliability of detecting a failed SCE, establishing a correspondence between the results of the diagnostic device (a posteriori information) and the data of the prior information bank on SCE failures depending on the specific conditions of their operation;

Diagram 3. Large-scale structural diagram of the APAO:

1 — test signals supplied to the FP input;

2 — FP response to tests;

3 — a posteriori information issued by the diagnostic device on the localization of the failed SCE;

4 — a priori information on the FP (includes information on the probability of FP failures depending on operating conditions, failure modeling results, FP analogs, etc.);

5 — information on the level of assessment of the reliability of the SCE failure (sufficient or insufficient);

6 — a decision to repeat the analysis of the SCE, the assessment of the reliability of the analysis of which is recognized as insufficient;

7 — a decision to move to an in-depth physical and technical analysis of the SCE, the assessment of the reliability of which is recognized as sufficient. prior information on SCE failures depending on the specific conditions of their operation;

• a device for forming a conclusion on the results of the analysis, on the basis of which a decision is made either on achieving sufficient reliability of the analysis of the failed SSE, or on the need to move to a repeated analysis at the previous level of the hierarchy with the involvement of additional a priori information or other methods (means) of technical diagnostics. Identification of causes and establishment of the mechanism of failures with the help of APAO should be carried out in such a way that at each stage of the analysis the integrity and operability of the elements subject to analysis at the next stage are not violated.

Criteria and indicators of the effectiveness of the ACD of the technical condition of the SCOB

The selection of criteria and corresponding performance indicators of the technical condition of the SKOB is carried out based on the following requirements:

• compliance with the goals and objectives of maintaining the SKOB in working condition;

• completeness of accounting of significant factors reflecting the properties of the SKOB, and the possibility of calculating them;

• sensitivity, i.e. the criticality of the indicators to changes in the main parameters of the SKOB.

Criteria for the effectiveness of the AKD.

The following can be adopted as the named criteria and corresponding indicators:

• ensuring that the results of the ACD reflect the actual technical condition of the SKOB objectively (reliability of control). This criterion corresponds to the indicator — the probability of the absence of undetected failures after the ACD (determined by the calculation and instrumental method);

• ensuring that the completeness of the ACD corresponds to the specified scope of control (completeness of control). This criterion corresponds to the indicator — the ratio of the number of parameters subjected to the ACD to the total number of controlled parameters specified by the control plan;

• obtaining information about the technical condition of individual functional subsystems and the SKOB as a whole, which is provided by the ACD, within the specified timeframes (the efficiency of the ACD). This criterion corresponds to the indicator — the average time to obtain the results of the ACD in a specified volume (determined by timing).

SKOB failure criteria.

Depending on the purpose and design and technical implementation of the functional subsystems of the SKOB, the following signs are selected individually or in combination as failure criteria:

• cessation of operation or decrease in efficiency (degree of suitability for intended use) of the functional subsystems in the SKOB;

• deviation from the norm of the main and auxiliary parameters;

• failure of the components of the functional subsystems of the SKOB (removable assembly units, etc.);

• occurrence of unscheduled processes (modes) in operation;

• achievement of the specified service life (resource);

• technical and economic inexpediency of continuing work (for example, increased downtime due to frequent repairs).

The selected failure criteria must be consistent with the characteristics of the testability of the functional subsystems in the SCBS, allowing for the greatest simplicity (organoleptically or using technical means) to detect the fact of failure, have a minimum (acceptable) time between the moment of failure and its detection, ensure maximum reliability and unambiguity (full compliance of the feature with the fact of failure).

Conclusion

To summarize the above, we can conclude that the outlines of the systems approach to ensuring automated control and diagnostics of the technical condition of the SCBS during its operation outlined in the article allow:
• to increase the level of technical maintenance of the SCBS in places of its intended use;

• reduce the cost of maintaining the personnel servicing the SCOB;
• prevent possible failures in operation caused by the “human factor”.

Journal «Peace and Security» No. 3-2011