both measurement and nonmeasurement, carried out by the system [12]. This extends the ex- isting concepts of metrological provisions for measuring devices and calls for resolving the problem of ensuring reliability in carrying out information and logical functions. Regard- less of the nontraditional nature of the stated problem, it is the most significant among problems relating to metrological provisions for fourth generation IMS.

LITERATURE CITED

i. K. B. Karandeev, Vest. Akad. Nauk SSSR, No. i0, 24 (1961). 2. M. P. Tsapenko, Information Measuring Systems [in Russian], Energoatomizdat, Moscow

(1985). 3. A. D. Pinchevskii, Metrological Provisions for Information Measuring Systems, Metrolog-

ical and Organizational Principles [in Russian], VISM, Moscow (1990). 4. E. S. Brailov, Checking and Certification of Information Measuring and Control Systems

[in Russian], Izd.-vo Standartov, Moscow (1988). 5. M. F. Yudin, M. N. Selivanov, et al., Basic Terms in Metrology. Reference Dictionary

[in Russian], Izd.-vo Standartov, Moscow (1989). 6. GOST 8.437-81, SSM. Information Measuring Systems. Metrological Provisions. Basic

Positions. 7. GOST 16263-70, Metrology, Terms and Definitions. 8. GOST 8.009-84, SSM. Normalized Metrological Characteristics of Measuring Devices. 9. A. L. Semenyuk and A. M. Krichevets, Izmer. Tekh., No. 2, 58 (1989).

i0. N. P. Vostroknutov, et al., Izmer. Tekh., No. 7, 6 (1990). ii. V. A. Kovalevskii, Methods of Optimum Solutions in Image Recognition [in Russian],

Nauka, Moscow (1976). 12. A. N. Vinnichenko and V. A. Granovskii, Theses of Reports of the 3rd All-Union Conf.

on "Metrological provisions for IMS and APPCS," [in Russian], VNIIMIUS, L'vov (1990), p. 17.

CHARACTERISTICS OF METROLOGICAL PROVISIONS FOR APPCS

M. I. Kornyukhov and N. N. Rogachev UDC 389.14:658.512.6.011.56

In resolving questions connected w~th metrological provisions for automated production process control systems (APPCS), we have to account for a series of characteristics distin- guishing them from other systems which carry out measurement functions (information measuring systems, measuring and computing systems, technical diagnostic systems, etc.). In this case, it is not the individual characteristics, but their totality that makes it possible to speak of the APPCS as a specific object for which metrological provisions have to be made and a self-contained system of rules, conditions, requirements, and norms aimed at obtaining the required measurement accuracy has to be developed.

We can identify the following characteristics that are inherent to a larger or smaller extent in APPCS in relation to the nature of production and the production process:

i. Prolonged (months) and continuous (without stoppage) character of operation. This is indicated by the production process regimes and procedures. There are considerable eco- nomic losses due to production stoppage. This characteristic does not facilitate random disconnection of APPCS from the object in order to undertake metrological maintenance.

2. The unbroken link between the APPCS and controlled production object (CPO) along with which the former constitutes a unified automated production complex. In many cases, the location and method of installation of the primary sensing units in the production equipment do not provide for access for carrying out metrological maintenance of the corre- sponding measuring channels (MC) as a whole (including the sensing unit). This makes it necessary to metrologically service the sensing elements and electric circuit separately.

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Translated from Izmeritel'naya Tekhnika, No. 8, pp. 5-6, August, 1991.

0543-1972/91/3408-0744512.50 �9 1992 Plenum Publishing Corporation

Here, in most cases, the design of the sensing units is generally not conducive to metro- logical servicing even with the APPCS stopped.

3. A steady-state operating regime of the automated systems of continuous production process control (most of the CPO) when, for most of the time (more than 90%)~ V alues of the measured production process and equipment parameters are closeto the irated, while those of the external influence factors are close to some steady-state values characteristic for that process.

It follows from this that, firstly, there is a conditionality in extending the results of any metrological tests carried out with stoppage of the production process to the normal operating regimes of the APPCS due to differences in parameters of the external medium and, secondly, there is a redundancy in the checking of the MC over the entire measuring range set by the technical assignment for the APPCS.

4. In a series of cases, there is a lack of information and time surplus in the APPCS during its operation (in most cases, there is no possibility of disconnecting the sensing units for metrological servicing of corresponding MC without adversely affecting the produc- tion process, small time margin for metrological servicing of the MC in the periods between successive interrogations, and lack of machine time of the APPCS for solving problems of control and processing of results of the required metrological experiments since the pro- cessor is loaded with the solution of the system's own problems). This means that even if it is possible to connect the required test equipment to the MC inputs, it is impossible to interrogate these channels and process the results of the checking when the APPCS is oper- ating in the production process control regime.

5. The "open" character of the APPCS which does not exclude unauthorized access to the MC and unauthorized changes in the technical and software components (this is a charac- teristic inherent even in some other systems).

6. The spatially dispersed nature of the APPCS when individual technical devices oper- ate under different (as a rule) environmental conditions. The spatial extent of the lines of communication is a source of additional errors.

7. The system is an object of capital construction (it is not released by the manufac- turer) and is not a manufactured product. The procedure for design, assembly, adjustment, tests, and putting the APPCS into operation is determined by special documents (State Stan- dards and State System's documents) in accordance with which the system occurs as a finished product only in the industrial object. Metrological testing of measuring channels of the APPCS can be carried out only at the industrial-experimental and operating stages.

8. Requirements for the APPCS are drawn up in accordance with the Standards ESS ASU as requirements for the functions of the APPCS and requirements provisions for the control system to cover the technical, mathematical, programming, organization, information, legal, and metrological aspects. In accordance with these documents, the design of the APPCS should contain a description of the technical solutions for these types of provisions for the sys- tem (and it is not obligatory for the design to contain any other information).

In this context, metrological provisions for specific designs of APPCS can be made by working out concrete technical solutions for each of the above types of provisions and by describing these in the design documents. In accordance GOST 1.25-76, these provisions in- corporate a set of requirements, conditions, rules, and norms of a technical, organizational, and legal character.

This sort of approach facilitates the identification of the following groups of require- ments for metrologicalprovisions for the APPCS, i.e., requirements for:

- initial data (including requirements for the metrological characteristics of the MC or accuracy in the required measurements);

- structure of the MC and composition and metrological (or accuracy) characteristics of components of technical devices and software of the MC;

- technical devices (including measuring devices) necessary for metrological testing of the MC;

- the subscriber points and data transmission equipment;

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- - the development of new measuring devices;

- means of communication between locations (points) at which parts of the MC are fitted;

- controlled production process object (as part of the requirements for methods of in- stallation of sensing units in the production equipment);

- algorithms for obtaining the measurement results;

- programs for processing the measurement information;

- composition and forms of documents for the metrological provisions (including the pro- gram and method of metrological certification and checking of the MC);

- methods of metrological testing of the MC;

- legal rules laying down legal relations in regard to personnel during operation of the APPCS;

- organization and sequence of metrological certification and checking of the MC;

- juridical status of the obtained measurement information;

- measures to safeguard the measurement information from unauthorized access and chang- es on the part of the personnel and in the control system problems.

In working out the metrological provisions for the APPCS, it is advisable to account for the characteristics of the control systems andthe following principles:

- a systems approach to the metrological provisions in which requirements for the sci- entific, organizational, technical, and legal bases of these provisions for the APPCS are formed from common positions; questions of metrological provisions for the CPO which are re- lated for the APPCS (but have a basic character) are examined, in particular, those of organ- izing the activities of the Departmental Metrological Service in the organization using the APPCS; unified requirements are worked out for the metrological provisions for the various components of the APPCS;

- maximum (where this is possible) continuity in the metrological provisions for the APPCS with those for the traditional independent measuring devices. This consists in using the adopted procedures for ensuring unanimity in the measurements (metrological inspection, certification, checking, etc.);

- as far as possible, the technical nature of problems solved in the APPCS and the tech- nical potential of the control system should be most fully taken into account for construct- ing the most effective metrological provisions for the APPCS (determination of a rational composition of the MC subjected to metrological certification, automation of the checking, built-in control of the metrological adaptability of the MC, and automatic error correction);

- correlation of the questions relating to metrological provisions for the APPCS with the phases and stages of development of the system and with types and contents of the design documents released;

- breaking up of the problems of metrological provisions to match the procedure in which the technical structure is resolved into elements during development of the APPCS. As a result, problems relating to metrological provisions for the MC, progran~ned technical sys- tems of the APPCS, and technical devices and software of the system are solved.

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