A course of lectures on the discipline “Technical means of automation and. Classification of automation equipment for food production processes

The classification of technical automation equipment is not something too complicated and loaded. However, in general technological means automation have a fairly extensive classification structure. Let's try to figure it out.

Modern means automation are divided into two groups: switched and non-commutated (programmed) technical means of automation:

1) Switched automation equipment

Regulators

Relay circuits

2) Programmed automation tools

ADSP processors

ADSP processors are an automation tool that is used for complex mathematical analysis of processes in the system. These processors have high-speed input/output modules that can transmit data at high frequencies to the central processor, which uses complex mathematics to analyze the operation of the system. An example is vibration diagnostic systems that use Fourier series for analysis, spectral analysis and a pulse counter. As a rule, such processors are implemented in the form of a separate PCI card, which is mounted in the appropriate slot of the computer and uses the CPU for mathematical processing.

PLC (Programmable Logic Controller)

PLCs are the most common automation tools. They have their own power supply, central processor, RAM, network card, input/output modules. The advantage is high reliability of the system, adaptation to industrial conditions. In addition, programs are used that run cyclically and have a so-called Watch Dog, which is used to prevent the program from freezing. Also, the program runs sequentially and does not have parallel connections and processing steps that could lead to negative consequences.

PKK (Programmable Computer Controllers)

PKK - computer with input/output cards, network cards, which serve for input/output of information.

PACK

PAK ( programmed automated controllers) – PLC+PKK. They have a distributed network structure for data processing (several PLCs and PCs).

· Specialized controllers

Specialized controllers are not freely programmable automation tools, but use standard programs in which only some coefficients can be changed (PID controller parameters, actuator running time, delays, etc.). Such controllers are focused on a previously known control system (ventilation, heating, hot water supply). At the beginning of the new millennium, these technical means of automation became widespread.

A feature of ADSP and PKK is the use of standard programming languages: C, C++, Assembler, Pascal, since they are created on a PC. This feature of automation tools is both an advantage and a disadvantage.

The advantage is that a more complex and flexible algorithm can be written using standard programming languages. The disadvantage is that to work with them you need to create drivers and use a programming language, which is more complex. The advantage of PLCs and PACs is the use of engineering programming languages ​​that are standardized by IEC 61131-3. These languages ​​are not designed for a programmer, but for an electrical engineer.

Principle of information transformation

Management principles are based on the principle of information transformation.

Converters are devices used to convert quantities of one physical nature into another and vice versa.

Sensors are devices that produce a discrete signal depending on the code of the technological process or the impact of information on them.

Information and methods for converting it

The information must have the following properties:

1. Information must be understandable in accordance with the adopted coding system or its presentation.

2. Information transmission channels must be noise-proof and prevent the penetration of false information.

3. Information must be convenient for processing.

4. Information should be convenient for storing it.

To transmit information, communication channels are used, which can be artificial, natural, or mixed.

Rice. 3. Communication channels

We will talk in more detail about communication channels a little later.

Technical automation equipment (TAA) is designed to create systems that perform specified technological operations, in which humans are mainly assigned control and management functions.

Based on the type of energy used, technical automation equipment is classified into: electric, pneumatic, hydraulic And combined. Electronic automation tools are classified as a separate group, since they, using electrical energy, are designed to perform special computing and measuring functions.

By functional purpose, technical automation equipment can be divided according to standard circuit automatic control systems for actuators, amplifiers, correcting and measuring devices, converters, computing and interface devices.

Executive element - This is a device in an automatic regulation or control system that acts directly or through a matching device on a regulatory element or object of the system.

Regulating element carries out a change in the operating mode of the managed object.

Electrical actuator with mechanical output - electric motor- used as a terminal amplifier of mechanical power. The effect an object or mechanical load has on an actuator is equivalent to the action of internal, or natural, feedback. This approach is used in cases where a detailed structural analysis of the properties and dynamic features of the actuating elements is required, taking into account the action of the load. An electrical actuator with a mechanical output is integral part automatic drive.

Electric drive - This is an electrical actuator that converts the control signal into a mechanical action while simultaneously amplifying it in power due to an external energy source. The drive does not have a special main feedback link and is a combination of a power amplifier, an electrical actuator, a mechanical transmission, a power source and auxiliary elements, united by certain functional connections. The output quantities of the electric drive are linear or angular speed, traction force or torque, mechanical power etc. The electric drive must have the appropriate power reserve necessary to influence the controlled object in forced mode.

Electric servomechanism is a servo drive that processes the input control signal with amplification of its power. The elements of the electrical servomechanism are covered by special feedback elements and can have internal feedback due to the load.

Mechanical transmission The electric drive or servomechanism coordinates the internal mechanical resistance of the actuator with the mechanical load - the regulatory body or the control object. Mechanical transmissions include various gearboxes, crank, lever mechanisms and other kinematic elements, including transmissions with hydraulic, pneumatic and magnetic supports.

Electrical power supplies actuators, devices and servomechanisms are divided into sources with practically infinite power, with a value of their internal resistance close to zero, and sources with limited power with a value of internal resistance different from zero.

Pneumatic and hydraulic actuators are devices that use gas and liquid, respectively, under a certain pressure as an energy carrier. These systems occupy a strong place among other automation equipment due to their advantages, which, first of all, include reliability, resistance to mechanical and electromagnetic influences, a high ratio of the developed drive power to its own weight and fire and explosion safety.

The main task of the actuator is to amplify the signal arriving at its input to a power level sufficient to have the required effect on the object in accordance with the stated control goal.

An important factor when choosing an actuator is to ensure the specified system quality indicators with the available energy resources and permissible overloads.

The characteristics of the actuator must be determined from the analysis of the automated process. Such characteristics of actuators and servomechanisms are energy, static, dynamic characteristics, as well as technical, economic and operational characteristics.

A mandatory requirement for the actuator drive is to minimize engine power while ensuring the required speeds and torques. This leads to minimization of energy costs. Very important factors When choosing an actuator or servomechanism, there are restrictions on weight, overall dimensions and reliability.

Important components of automation systems are amplification and correction devices. Common tasks solved by correction and amplification devices of automation systems are the formation of the required static and frequency characteristics, synthesis of feedback, coordination with the load, ensuring high reliability and unification of devices.

Amplifier devices the power of the signal is amplified to the level necessary to control the actuator.

Special requirements for corrective elements of systems with variable parameters are the possibility and ease of restructuring the structure, program and parameters of corrective elements. Amplifier devices must satisfy certain technical specifications by specific and maximum output power.

The structure of an amplification device is, as a rule, a multistage amplifier with complex feedback connections, which are introduced to improve its static, dynamic and operational characteristics.

Amplification devices used in automation systems can be divided into two groups:

1) electrical amplifiers with electrical power sources;

2) hydraulic and pneumatic amplifiers, using liquid or gas, respectively, as the main energy carrier.

The power source or energy carrier determines the most essential features of automation amplification devices: static and dynamic characteristics, specific and maximum power, reliability, operational and technical and economic indicators.

Electrical amplifiers include electronic vacuum, ionic, semiconductor, dielectric, magnetic, magnetic-semiconductor, electric machine and electromechanical amplifiers.

Quantum amplifiers and generators constitute a special subgroup of devices used as amplifiers and converters of weak radio and other signals.

Corrective devices generate correction signals for the static and dynamic characteristics of the system.

Depending on the type of inclusion in the system, linear corrective devices are divided into three types: serial, parallel corrective elements and corrective feedback. The use of one or another type of correction devices is determined by the convenience of technical implementation and operational requirements.

It is advisable to use corrective elements of the sequential type if the signal, the value of which is functionally related to the error signal, is an unmodulated electrical signal. The synthesis of a sequential correction device in the process of designing a control system is the simplest.

Parallel type correction elements are convenient to use when forming a complex control law with the introduction of an integral and derivatives of the error signal.

Corrective feedback, covering amplifiers or actuators, is most widely used due to the simplicity of its technical implementation. In this case, the input of the feedback element receives a relatively high level signal, for example, from the output stage of an amplifier or motor. The use of corrective feedback makes it possible to reduce the influence of nonlinearities of those system devices that are covered by them; therefore, in some cases it is possible to improve the quality of the control process. Corrective feedback stabilizes the static coefficients of the covered devices in the presence of interference.

Automatic regulation and control systems use electrical, electromechanical, hydraulic and pneumatic corrective elements and devices. Electrical correction devices are most simply implemented using passive quadripoles, which consist of resistors, capacitors and inductances. Complex electrical correction devices also include separating and matching electronic elements.

Electromechanical correction devices, in addition to passive quadripoles, include tachogenerators, impellers, differentiating and integrating gyroscopes. In some cases, an electromechanical correction device can be implemented in the form of a bridge circuit, in one of the arms of which an electric motor of the actuator is connected.

Hydraulic and pneumatic correction devices can consist of special hydraulic and pneumatic filters included in the feedback loops of the main elements of the system, or in the form of flexible feedback loops for pressure (pressure difference), flow rate of working fluid, or air.

Corrective elements with tunable parameters ensure system adaptability. The implementation of such elements is carried out using relay and discrete devices, as well as computers. Such elements are usually referred to as logical corrective elements.

A computer operating in real time in a closed control loop has practically unlimited computing and logical capabilities. The main function of the control computer is to calculate optimal controls and laws that optimize the behavior of the system in accordance with one or another quality criterion during its process. normal use. The high speed of the control computer allows, along with the main function, to perform a number of auxiliary tasks, for example, with the implementation of a complex linear or nonlinear digital correction filter.

In the absence of computers in systems, it is most advisable to use nonlinear correcting devices as they have the greatest functional and logical capabilities.

Regulating devices They are a combination of actuators, amplifying and correcting devices, converters, as well as computing and interface units.

Information about the parameters of the control object and about possible external influences affecting it comes to the control device from the measuring device. Measuring devices in the general case, they consist of sensitive elements that perceive changes in the parameters by which the process is regulated or controlled, as well as additional converters that often perform signal amplification functions. Together with sensitive elements, these converters are designed to convert signals of one physical nature into another, corresponding to the type of energy used in the automatic regulation or control system.

In automation converting devices or converters These are elements that do not directly perform the functions of measuring regulated parameters, amplifying signals or correcting the properties of the system as a whole and do not have a direct impact on the regulatory body or the controlled object. Converting devices in this sense are intermediate and perform auxiliary functions associated with the equivalent transformation of a quantity of one physical nature into a form more convenient for the formation of a regulatory effect or for the purpose of coordinating devices that differ in the type of energy at the output of one and the input of another device.

Computer devices for automation equipment are, as a rule, built on the basis of microprocessor-based tools.

Microprocessor- a software-controlled tool that carries out the process of processing and managing digital information, built on one or more integrated circuits.

The main technical parameters of microprocessors are the bit depth, addressable memory capacity, versatility, the number of internal registers, the presence of microprogram control, the number of interrupt levels, the type of stack memory and the number of main registers, as well as the composition of the software. Based on their word width, microprocessors are divided into microprocessors with a fixed word width and modular microprocessors with variable word width.

By microprocessor means are structurally and functionally complete products of computer and control equipment, built in the form or on the basis of microprocessor integrated circuits, which, from the point of view of requirements for testing, acceptance and delivery, are considered as a single whole and are used in the construction of more complex microprocessor tools or microprocessor systems.

Structurally, microprocessor means are made in the form of a microcircuit, single-board product, monoblock or standard complex, and products of the lower level of the structural hierarchy can be used in products of the highest level.

Microprocessor systems - These are computing or control systems built on the basis of microprocessor-based tools that can be used autonomously or integrated into a controlled object. Structurally, microprocessor systems are made in the form of a microcircuit, a single-board product, a monoblock complex or several products of the indicated types, built into the equipment of the controlled object or made autonomously.

According to the scope of application, technical means of automation can be divided into technical means of automation of work in industrial production and technical means of automation of other work, the most important component of which is work in extreme conditions where human presence is life-threatening or impossible. In the latter case, automation is carried out on the basis of special stationary and mobile robots.

Technical means of automation of chemical production: Reference. ed./V.S.Balakirev, L.A.Barsky, A.V.Bugrov, etc. - M.: Chemistry, 1991. –272 p.

Management, consulting and entrepreneurship

Lecture 2. General information about technical means of automation. The need to study general issues related to technical automation equipment and state system industrial devices and automation equipment GSP is dictated by the fact that technical means

Lecture 2.

General information about technical means of automation.

The need to study general issues relating to technical automation equipment and the state system of industrial instruments and automation equipment (GSP) is dictated by the fact that technical automation equipment is an integral part of the GSP. Technical automation equipment represents the basis for the implementation of information and control systems in the industrial and non-industrial spheres of production. The principles of organizing the GSP largely determine the content of the design stage technical support automated process control systems (APCS). In turn, the basis of GSPs are problem-oriented aggregate complexes of technical means.

Typical automation tools can be technical, hardware, software and system-wide.

TO technical means of automation(TSA) include:

• sensors;
• actuators;
• regulatory authorities (RO);
• communication lines;
• secondary instruments (displaying and recording);
• analog and digital control devices;
• programming blocks;
• logic-command control devices;
• modules for collecting and primary processing of data and monitoring the state of a technological control object (TOU);
• modules for galvanic isolation and signal normalization;
• signal converters from one form to another;
• modules for data presentation, indication, recording and generation of control signals;
• buffer storage devices;
• programmable timers;
• specialized computing devices, pre-processor preparation devices.

TO software and hardware automation tools include:

• analog-to-digital and digital-to-analog converters;
• control means;
• multi-circuit analog and analog-to-digital control blocks;
• multi-connection program logic control devices;
• programmable microcontrollers;
• local area networks.

TO system-wide automation tools include:

• interface devices and communication adapters;
• shared memory blocks;
• highways (buses);
• general system diagnostic devices;
• direct access processors for storing information;
• operator consoles.

Technical means of automation in control systems

Any system control must perform the following functions:

• collecting information about current state technological control object (TOU);
• determination of quality criteria for TOU work;
• finding the optimal mode of operation of the TOU and optimal control actions that ensure the extremum of quality criteria;
• implementation of the found optimal mode at the TOU.

These functions may be performed by maintenance personnel or TCAs. There are fourtype of control systems(SU):

1) informational;

2) automatic control;

3) centralized control and regulation;

4) automated process control systems.

Information ( manual) control systems(Fig. 1.1) are rarely used, only for reliably functioning, simple technological objects of TOU control.

Rice. 1.1. Structure information system controls:

D - sensor (primary measuring transducer);

VP - secondary indicating device;

OPU - operator control center (boards, consoles, mnemonic diagrams, alarm devices);

Remote control devices remote control(buttons, keys, bypass control panels, etc.);

IM actuator;

RO - regulatory body;

C - alarm devices;

MS mnemonic diagrams.

In some cases, the information management system includes regulators direct action and regulators built into process equipment.

In automatic control systems(Fig. 1.2) all functions are performed automatically using appropriate technical means.

Operator functions include:

• technical diagnostics of the ACS condition and restoration of failed system elements;
• correction of regulatory laws;
• change of task;
• transition to manual control;
• equipment maintenance.

Rice. 1.2. Structure of the automatic control system (ACS):

KP - encoding converter;

LS - communication lines (wires, impulse tubes);

VU - computing devices

Centralized control and regulation systems(SCCR) (Fig. 1.3). ACS are used for simple technical equipment, the operating modes of which are characterized by a small number of coordinates, and the quality of work is characterized by one easily calculated criterion. A special case of self-propelled guns is automatic system regulation (ASR).

A control system that automatically maintains an extreme TOC value belongs to the class of extreme control systems.

Rice. 1.3. Structure of the centralized control and regulation system:

OPU - operator control center;

D - sensor;

NP normalizing converter;

KP - encoding and decoding converters;

CR - central regulators;

MP multi-channel registration tool (print);

C - pre-emergency signaling device;

MPP - multi-channel indicating devices (displays);

MS - mnemonic diagram;

IM - actuator;

RO - regulatory body;

K controller

ASRs that support the specified value of the output adjustable coordinate of the TOU are divided into:

• stabilizing;
• software;
• followers;
• adaptive.

Extreme regulators are used extremely rarely.

Technical structures of the SCCR can be of two types:

1) with individual TCAs;

2) with collective TCAs.

In the first type of system, each channel is constructed from TCA personal use. These include sensors, normalizing converters, regulators, secondary devices, actuators, and regulatory bodies.

Failure of one control channel does not lead to a shutdown of the process facility.

This design increases the cost of the system, but increases its reliability.

The second type system consists of TSA for individual and collective use. TSA for collective use includes: switch, CP (encoding and decoding converters), CR (central regulators), MR (multi-channel recording device (print)), MPP (multi-channel indicating devices (displays)).

The cost of a collective system is somewhat lower, but reliability largely depends on the reliability of collective TSAs.

When the communication line is long, individual encoding and decoding converters are used, located near the sensors and actuators. This increases the cost of the system, but improves the noise immunity of the communication line.

Automated process control systems(APCS) (Fig. 1.4) is a machine system in which TSA obtain information about the state of objects, calculate quality criteria, and find optimal control settings. The operator’s functions are reduced to analyzing the received information and implementing it using local automated control systems or remote control of the control room.

The following types of process control systems are distinguished:

• centralized automated process control system (all information processing and control functions are performed by one control computer UVM) (Fig. 1.4);

Rice. 1.4. Structure of a centralized automated process control system:

USO - communication device with an object;

DU - remote control;

SOI - information display tool

• supervisory automated process control system (has a number of local automatic control systems built on the basis of individual use TSA and a central computer computer (CUVM), which has an information line of communication with local systems) (Fig. 1.5);

Rice. 1.5. Structure of the supervisory control system: LR - local regulators

• distributed automated process control system - characterized by the division of information processing and management control functions between several geographically distributed objects and computers (Fig. 1.6).

Rice. 1.6. Hierarchical structure of technical means of SHG

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References 1. Kremlevsky P. P. - Flow meters and quantity counters of substances (2 books) - S. P.: Polytechnic, 2002 2. Ranev G. G., Tarasenko A. P., Methods and measuring instruments. – M.: Publishing center “Akkademia”, 2004 – 336 p. 3. Isakovich R. Ya., Kuchin B. L., Control and automation of oil and gas production. – M.: Nedra, 1976. – 343 p. 4. Movsumzade A. E., Soshchenko A. E., Development of automation and telemechanization systems in the oil and gas industry. – M.: Nedra, 2004 – 331 p. 5. Korshak A. A., Shammazov A. M., Fundamentals of oil and gas business, textbook for universities. – Ufa: LLC “Design. Polygraph. Service", 2005 – 528 p. : ill.

References 6. Logachev V. G., Development of means for automatic control of the dimensions of moving products with unstable and complex geometric shapes. – Tyumen: Vector Buk, 2001. – 311 p. 7. V. G. Domrachev, V. R. Matveevsky, Yu. S. Smirnov. Circuitry of digital displacement transducers. Reference Guide, M: Energoavtomizdat, 1987. 8. Samkharadze T. G. - Catalog. Instruments and automation equipment. Volume 6 - Secondary devices - M.: LLC Nauchtekhlitizdat, 2005 9. Samkharadze T. G. - Catalog. Instruments and automation equipment. Volume 7 – Regulating devices. Temperature, pressure, level alarms. Relay sensors. Actuators - M.: LLC Nauchtekhlitizdat, 2005 10. Samkharadze T. G. - Catalog. Instruments and automation equipment. Volume 8 – Program logic controllers (PLC) and software and hardware complexes (PTK) – M.: Nauchtekhlitizdat LLC, 2005.

Primary transducers A primary displacement transducer (PT) is a device that perceives a controlled input displacement (linear or angular) and converts it into an output signal (usually electrical), convenient for further processing, conversion and, if necessary, transmission via a communication channel to long distances. Being the most important component of digital converters, primary displacement converters largely predetermine the parameters of the digital processing unit as a whole, since it is the first stage of conversion, displacement - electrical parameter, that mainly determines such characteristics of the digital processing unit as accuracy, speed, linearity of control, etc. Basic requirements that requirements for the development and design of motion control devices: high accuracy of measurement (or control) of displacements, speed, reliability, noise immunity of the informative parameter, low nonlinear distortions, high manufacturability, low cost, low heat transfer, dimensions, weight, etc., which is quite important. in production conditions.

Classification of primary converters ¢ ¢ ¢ ¢ PP can be classified according to various signs, the main of which are: the nature of the measured movements, the physical principle of operation of the sensitive element, the structure of the structure, the type of output signal. Based on the nature of the measured movements, the PPs of linear and angular movements are distinguished. According to the physical principle of operation of the sensitive element, PPs can be divided into: photoelectric (optoelectronic), using the effect of periodic changes in illumination; electrostatic: l capacitive (based on the effect of periodic change in capacitance); l piezoelectric (based on the effect of the appearance electric charge on the surface of some materials at the time of deformation); electromagnetic (using, for example, the effect of periodic changes in inductance or mutual inductance); electroacoustic (based, for example, on the effect of changing the energy of a surface acoustic wave);

Classification of primary converters ¢ electromechanical: l electric contact (based on the effect of a sharp change in the resistance of paired electrical contacts when they are closed and opened); l rheostat (using the effect of linear change in resistance); l mechatronic (based on mechanical control of the electronic current of electrovacuum devices by direct mechanical movement of their electrodes). l According to the construction structure, depending on the method of connecting the elements of the PP, three main structural diagrams are distinguished: with sequential conversion, differential and compensation. l Based on the nature of the change in time of the output signal, continuous and discrete PPs are distinguished. l Depending on the type of the output signal parameter, which is linearly dependent on the measured displacement, PP continuous action are divided into amplitude, frequency and phase. Accordingly, discrete-action PPs can be amplitude-pulse, frequency-pulse, pulse-code, etc.

Classification of measurements ¢ ¢ ¢ Direct measurement - a measurement in which the desired value of a quantity is obtained directly. For example, measuring air temperature with a thermometer, pressure with a pressure gauge. Indirect measurement is a measurement in which the value of a physical quantity is determined based on the results of direct measurements of other physical quantities that are functionally related to the desired one. For example, finding the density of a body based on its mass and geometric dimensions. Joint measurements are simultaneous measurements of two or more heterogeneous quantities to establish the relationship between them. The accuracy of a measurement result is a characteristic of the quality of a measurement, reflecting the closeness to zero of the error of its result (the smaller the measurement error, the greater its accuracy). The error of a measurement result is the deviation of the measurement result from the true value of the measured value.

Measuring instruments A measuring instrument is a technical means (or a set of technical means) intended for measurements, having standardized metrological characteristics, reproducing or storing one or more units of physical quantities, the dimensions of which are assumed to be unchanged over a known period of time. ¢ Measuring device – a measuring instrument designed to obtain the values ​​of the measured quantity within a specified range. As a rule, a measuring device has devices for converting the measured quantity into a signal of measuring information and displaying it in a form that is most accessible to perception. The following types of instruments are distinguished: indicating, recording, summing, direct action, comparison. ¢ Accuracy class is a generalized characteristic of measuring instruments, determined by the limits of permissible basic and additional errors, as well as other properties of SI that affect its accuracy. ¢ The error of a measuring instrument is the difference between the SI readings and the true (actual) value of the measured quantity. ¢

Shut-off valves ¢ ¢ ¢ Pipeline accessories designed to control oil flows transported through pipelines. According to the principle of operation, valves are divided into three classes: shut-off, control and safety. Shut-off valves (valves) are used to completely shut off the cross-section of the pipeline, regulating valves (pressure regulators) - to change the pressure or flow rate of the pumped liquid, safety valves (check valves and safety valves) - to protect pipelines and equipment when the permissible pressure is exceeded, as well as to prevent backflows liquids. Gate valves are shut-off devices in which the flow area is closed by translational movement of the gate in the direction perpendicular to the direction of oil movement.

Shut-off valves Pressure regulators are devices used to automatically maintain pressure at the required level. In accordance with where the pressure is maintained before or after the regulator, there are regulators of the “before” and “after” types. ¢ Safety valves are devices that prevent pressure in a pipeline from increasing above a set value. On oil pipelines, low- and full-lift closed-type safety valves are used, which operate on the principle of discharging part of the liquid from the point where high pressure occurs into a special collection manifold. ¢ A non-return valve is a device for preventing the reverse movement of a medium in a pipeline. When pumping oil, rotary check valves with a shutter rotating about a horizontal axis are used. The valves of main oil pipelines are designed for operating pressure 6.4 MPa. ¢

Automation of production is a process in the development of machine production, in which management and control functions previously performed by humans are transferred to instruments and automatic devices. Automation of production is the basis for the development of modern industry, the general direction of technical progress. Its main goal is to increase labor efficiency, improve the quality of products, and create conditions for the optimal use of all production resources. A. p. is distinguished: partial, complex and complete.

Methods of production automation ¢ Firstly, they develop methods for effectively studying the patterns of control objects, their dynamics, stability, dependence of behavior on influence external factors. These problems are solved by researchers, designers and technologists, specialists in specific fields of science and production. Complex processes and objects are studied by methods of physical and mathematical modeling, operations research using analog and digital computers.

Production automation methods ¢ Secondly, they determine economically feasible management methods, carefully substantiate the purpose and evaluation function of management, and the choice of the most effective relationship between measured and control process parameters. On this basis, rules for making management decisions are established and a strategy for the behavior of production managers is chosen, taking into account the results of economic research aimed at identifying rational patterns of the management system. Specific management goals depend on technical, economic, social and other conditions. They consist of achieving maximum process productivity, stabilizing the high quality of products, the highest utilization rate of fuel, raw materials and equipment, the maximum volume of products sold and reducing costs per unit of product, etc.

Methods of production automation ¢ Thirdly, the task is to create engineering methods for the most simple, reliable and effective implementation of the structure and design of automation equipment that carries out specified functions measurement, processing of obtained results and management. When developing rational control structures and technical means for their implementation, the theory of algorithms, automata, mathematical logic and the theory of relay devices are used. With the help of computer technology, many processes of calculation, design and testing of control devices are automated. The selection of optimal solutions for collecting, transmitting and processing data is based on methods of information theory. If there is a need for multi-purpose use of large flows of information, centralized (integrated) methods of processing it are used.

Automation means Technical automation means instruments, devices and technical systems, intended for production automation. T.s. A. provide automatic receipt, transmission, transformation, comparison and use of information for control and management purposes production processes. Sensor is a primary transducer, an element of a measuring, signaling, regulating or control device of a system that converts a controlled quantity (pressure, temperature, frequency, speed, movement, voltage, electric current, etc.) into a signal convenient for measurement, transmission, conversion, storage and registration, as well as for their impact on managed processes.

Methods and instruments for measuring temperature Temperature refers to the degree of heating of a substance. The physical properties of oil (density, viscosity, amount of gas and paraffin dissolved in oil, and phase states of oil) largely depend on its temperature. The technology of the process of oil production, field collection and primary preparation in the fields, transportation of oil and petroleum products largely depend on the temperature factors at which these processes occur. Since temperature is an active quantity, it can only be measured indirectly, based on the temperature dependence of such physical properties of bodies that can be directly measured (thermo. EMF, electrical resistance, density, etc.). Temperature must be measured in pipelines with coolant, in water-bearing, oil-bearing and compressor stations to monitor the condition of bearings. Temperature measurements in tanks with oil and petroleum products are a necessary element of quantitative accounting.

Temperature sensor Metran - 274 The sensor consists of an electronic converter with an output signal of 4-20 m. A and thermal probes with different lengths of the immersed part. The measured temperature parameter is linearly converted into a proportional change in the ohmic resistance of the thermistor placed in the temperature probe. An electronic converter converts the voltage generated by the temperature-sensitive element into a current output signal. The temperature-sensitive element of the sensor is a thermistor with a nominal static conversion characteristic of 100 M, located in the hermetic shell of the temperature probe.

Temperature sensor TC 5008 The sensor is designed for continuous conversion of the temperature of liquids and gases into a unified current output signal in non-aggressive environments in automatic control, regulation and process control systems. An electronic converter converts the voltage generated by the temperature-sensitive element into a current output signal.

Temperature sensors TSMU 0104, TSPU 0104 Thermal converters with a unified output signal TSMU 0104, TSPU 0104 are designed for measuring and continuously converting temperature of solid, liquid, gaseous and granular substances. TSMU 0104, TSPU 0104 are designed to replace thermal converters with a unified output signal of the TSMU 205, TSPU 205 series. They are distinguished by the ability to change the temperature probe and select the lower and upper limits of the measured temperature range using switches. In accordance with GOST 14254 degree of protection against penetration solids, dust and water: IP 54, IP 65, IP 67 depending on the design of the terminal head and the type of connection.

Main technical characteristics of temperature sensors TS 5008, Metran-274, TSMU 0104 (TSPU 0104) Device name Parameters TS 5008 Metran 274 TSMU 0104, TSPU 0104 ± 0.5 ± 0.25 ± 0.1 50 to +350 50 to +180 50 to 550 Used output signal, m. A 4 20 Supply voltage, V 17 42 15 42 Explosion-proof protection. Service life, years 5 5 6 1, 5 1, 8 1, 08 Limit of permissible error, % Range of measured temperatures, ºС Price, thousand rubles

Classification of instruments for measuring pressure and vacuum All instruments for measuring pressure and vacuum can be divided into the following groups: 1. By the type of quantity being measured: barometers - for measuring atmospheric pressure; pressure gauges - for measuring excess pressure; vacuum gauges - to measure vacuum; pressure and vacuum gauges - for measuring pressure and vacuum; differential pressure gauges - for measuring the difference (difference) in pressure.

Classification of instruments for measuring pressure and vacuum 2. Based on the principle of operation: liquid - the measured pressure is balanced by a column of liquid; piston - the measured pressure acting on one side of the piston is balanced by the pressure created by the force applied on the opposite side. The direct load(s) is used as a balancing force; spring - the measured pressure deforms various types of springs. The deformation, increased by the transmission of a precision mechanism and converted into pointer movement, is a measure of the measured pressure; electrical, based on changes in the electrical properties of certain materials when pressure is applied to them; radioactive - the measured pressure causes a corresponding change in ionization produced by radiation and recombination of ions. Liquid instruments are used mainly in laboratory conditions, piston pressure gauges are used for calibrating instruments. On industrial facilities Spring and electric pressure gauges of various types are mainly used.

Pressure sensor Sapphire-22-DI-Ex Measuring transducers Sapphire-22-DI-Ex are designed for operation in systems of automatic monitoring, regulation and control of technological processes and provide continuous conversion of the value of the measured parameter - excess pressure - into a unified current output signal. The converters are designed to work with secondary recording and display equipment, regulators and other automation devices, control systems operating from a standard output signal of 4-20 mA DC. The operating principle of the Sapphire-22-DI-Ex converter is based on the use of strain gauges. Sapphire-22-DI-Ex converters have high accuracy, stable operation, and low inertia. Sensors are manufactured in the form of multi-range devices with the ability to adjust the measurement range.

Pressure sensor Metran-43 DI-Ex Sensors of this type are designed to work in a system of automatic monitoring, regulation and control of technological processes and provide continuous conversion of the value of the measured parameter - excess pressure - into a standard current output signal for remote transmission. The operation of Metran-43 DI-Ex measuring transducers is based on the strain-resistor effect. Converters of this model have high accuracy, stable operation, and low inertia. The sensors are manufactured in the form of multi-range devices with the ability to adjust the measurement range: each converter can be reconfigured to any upper measurement range. The sensitive element is protected from the measured medium by corrugated metal membranes made of anti-corrosion materials. The main advantages are increased accuracy; however, the use of this sensor in an automated process is complicated by its large dimensions and narrow operating temperature range.

Differential pressure measurement sensor SAPFIR - 22 -Ex-M-DD Differential pressure converters can be used to convert liquid level values, liquid or gas flow rates, hydrostatic pressure conversion to convert liquid level values ​​into a unified current signal. Each transducer has a measurement range adjustment and can be set to any upper measurement limit specified for that model. The limit of permissible basic error is up to 0.5%. Converters "SAPHIRE 22 Ex M DD" are made with the type of explosion protection "intrinsically safe electrical circuit" with the level of explosion protection "extra explosion-proof". Can work in explosive areas indoors and outdoors. The operating principle of converters is based on the properties of materials to change their electrical parameters (capacitance, resistance) when their geometry changes. As a sensitive element in the converters, a layer of strain resistance is used, deposited by vacuum diffusion onto a sapphire plate (the so-called “silicon on sapphire” SOS structure) connected to a metal plate. When the pressure exerted on the plate changes, the resistance of the strain gauges connected to one of the arms of the equalizing bridge changes, resulting in an imbalance in the bridge circuit. Thus, a change in pressure or differential pressure is converted into an output current signal of 4-20 mA. The maximum permissible operating overpressure is up to 40 MPa.

Main technical characteristics of pressure sensors Sapphire-22-DI-Ex, Metran-43 DI-Ex, Sapphire - 22-Ex-M-DD Device name Parameters Sapphire 22 DI Ex Metran 43 DI Ex Sapphire 22 Ex M DD ± 0.5 ± 0.25 ± 0.5 from 0 to 2.5 50 to +80 50 to +70 50 to 550 Used output signal, m. A 4 20 Supply voltage, V 15 42 explosion-proof. Service life, years 10 8 12 Price, thousand rubles. 13 8 17 Permissible error limit, % Measurement limit, MPa Range of measured temperatures, ºС Protection

Operating principle of ultrasonic level gauges Ultrasonic non-contact level gauges probe the working area with ultrasound waves, i.e. pressure waves with a frequency above 20 KHz. They use the property ultrasonic waves reflected when passing the boundary of two environments with different physical properties. Therefore, the sensitive element of an ultrasonic level gauge consists of an emitter and a vibration receiver, which, as a rule, are structurally combined and represent a quartz plate. When an alternating voltage is applied to the plate, deformations of the plate occur, transmitting vibrations to the air environment. The voltage is supplied in pulses and upon completion of the transfer, the plate turns into a receiver of reflected ultrasonic vibrations, causing vibrations of the plate and, as a result, the appearance of an output voltage (reverse piezoelectric effect). The distance to the interface between two media is calculated by the formula: H = V * t /2, where V is the speed of ultrasonic waves in a given medium, t is the time between the start of radiation and the arrival of the reflected signal, determined electronic unit level gauge.

Operating principle of ultrasonic level meters As a rule, the most common option is to install an ultrasonic sensor in the upper part of the tank. In this case, the signal passes through the air, reflecting from the boundary with the solid (liquid) medium. The level gauge in this case is called acoustic. There is also the option of installing the sensor in the bottom of the container. In this case, the signal is reflected from the boundary with a less dense medium. The speed of propagation of ultrasound depends on temperature about 0.18% per 1ºC. To eliminate this influence, temperature compensation is used in unit level gauges using a built-in temperature sensor. The operating range of ultrasonic level meters is up to 25 m, with an unmeasured level of about 1 m. Working environment temperature: 30. . +80(120) ºС, pressure – up to 4 MPa. Ultrasonic level meters can achieve a level measurement error of 1%. They can be used for aggressive media and for media with a wide variety of physical properties, with the exception of highly steaming, highly foaming liquids and fine and porous granular bulk products. At the same time, they are significantly cheaper than microwave radar level meters. Ultrasonic level meters are often used to measure flow in profiled channels. Examples of common ultrasonic level meters are: ECHO-5, ECHO-AS 01, Prosonic M.

Microwave radar level meters are the most complex and high-tech level measurement devices. To probe the working area and determine the distance to the test object, electromagnetic radiation of the microwave range is used here. Currently, two types of microwave level meters are widely used: pulse and FMCW (frequency modulated continuous wave). In FMCW level gauges, there is a constant continuous emission of a linearly frequency modulated signal and, at the same time, reception of the reflected signal using the same antenna. The result is a mixture of signals at the output, which is analyzed using special mathematics and software to isolate and most accurately determine the frequency of the useful echo signal. For each moment of time, the difference in frequencies of the forward and reverse signals is directly proportional to the distance to the controlled object. Pulsed microwave level meters emit a signal in a pulsed mode, and the reflected signal is received in the intervals between pulses of the original radiation. The device calculates the travel time of the forward and reverse signals and determines the distance to the controlled surface.

Microwave radar level gauges Radar level gauges are the most versatile means of level measurement. Without direct contact with the controlled environment, they can be used for aggressive, viscous, heterogeneous liquids and bulk materials. They are distinguished from ultrasonic non-contact level gauges by their much lower sensitivity to temperature and pressure in working capacity, to their changes, as well as greater resistance to such phenomena as dust, evaporation from the controlled surface, and foaming. Radar level gauges provide high accuracy (up to +/ 1 mm), which allows their use in commercial metering systems. At the same time, a significant limiting factor in the use of radar level meters remains high price these devices.

The principle of operation of displacer level gauges The method of determining the level by the buoyant force acting on a displacer immersed in the working fluid is used by displacer level gauges. A sinking buoy is subject to a buoyancy force in accordance with Archimedes' law, proportional to the degree of immersion and, accordingly, to the level of the liquid. The action of this force is perceived by a strain gauge transducer (level gauges of the Sapphire DU type), or an inductive transducer (UB EM), or a damper blocking the nozzle (pneumatic level gauges of the PIUP type). Displacer level gauges are designed to measure level in the range of up to 10 m at temperatures of - 50. +120ºС (in the range of +60... 120ºС in the presence of a heat-removing pipe; at temperatures of 120... 400°С the devices operate as level indicators) and pressure up to 20 MPa, providing an accuracy of 0.25. 15%. Density of the controlled liquid: 0, 4... 2 g/cm 3. Displacer level gauges are often used to measure the interface level of two liquids. It is also possible to use them to determine the density of the working environment at a constant level.

Technical characteristics of PIUP Symbol of modifications of the converter Maximum permissible operating excess pressure, MPa Upper Range of measurement density limit, m of measured liquid, g/cm³ Temperature range of measured medium, °C PIUP 11 10; 16 0.25 16.0 50 +100 0.5 1.2 or 1.0 2.0

Displacer pneumatic level transducer PIUP Purpose: the device is designed to control the liquid level or the interface level of two immiscible liquids in automatic control systems technological processes with increased fire safety requirements. The devices are used in the chemical, oil and gas industries in conjunction with recorders and actuators operating from a standard pneumatic signal of 20-100 kPa. The device includes: a displacer with a cable suspension, a set of spare parts, a bottle with damping liquid. For models PIUP 13 and PIUP 15 - a set of mounting parts with a heat-dissipating pipe.

Hydrostatic level gauges Hydrostatic level gauges measure the pressure of a liquid column and convert it into a level value, since hydrostatic pressure depends on the level and density of the liquid and does not depend on the shape and volume of the tank. They are differential pressure sensors. Medium pressure is supplied to one of the inputs connected to the tank. The other inlet is connected to the atmosphere in the case of an open container without excess pressure, or connected to the area of ​​excess pressure in the case of a closed container under pressure. Structurally, hydrostatic sensors are of two types: membrane and bell (submersible). In the first case, a strain-resistive or capacitive sensor is directly connected to the membrane and the entire device is located at the bottom of the container, usually on the side on the flange, while the location of the SE (membrane) corresponds to the minimum level. (Sapphire-DG, Metran 100 DG, 3051 L). In the case of a bell sensor, the sensitive element is immersed in the working medium and transmits fluid pressure to the strain-resistive sensor through an air column sealed in the supply tube.

Hydrostatic level gauges Hydrostatic level gauges are used for homogeneous liquids in containers without significant movement of the working medium. They allow measurements in the range of up to 250 kPa, which corresponds (for water) to 25 and meters, with an accuracy of 0.1% at an excess pressure of up to 10 MPa and a working medium temperature: - 40. . +120°С. Hydrostatic level transmitters can be used for viscous liquids and pastes. An important advantage of hydrostatic level meters is their high accuracy with relative cheapness and simplicity of design.

Smart Devices The term "smart" primary devices was coined for those primary devices that contain a microprocessor inside. This usually adds new functionality that was not present in similar devices without a microprocessor. For example, a smart sensor can provide more accurate readings by using numerical calculations to compensate for sensing element non-linearity or temperature dependence. A smart sensor has the ability to work with a wide variety of different types of sensing elements, as well as combine one or more measurements into one new measurement (for example, volume flow and temperature into gravimetric flow). Finally, the smart sensor allows for adjustment to a different measurement range or semi-automatic calibration, as well as internal self-diagnostic functions, which simplifies maintenance.

Controllers Currently, the automation market offers a huge number of different programmable logic controllers. They are produced by many well-known companies involved in the development of automation tools. Currently, PLC is produced by more than 50 manufacturers: Siemens, Allen Bradley, Octagon Systems, GE, Koyo, ABB, Advantech, etc.

Controllers A controller (English controller, regulator, control device) is an electrical device with the help of which in telemechanics and control systems they measure currents, voltages, temperatures and other physical parameters of an object, transmit and receive data via communication channels, transmit control actions to the object, use as a local automatic regulator. Currently, controllers are quite small-sized devices, so the name microcontrollers is often used. As a rule, controllers are equipped with microprocessor hardware that allows you to program the controller to solve a given range of tasks, hence other names: programmable controllers and programmable logic controllers, which are usually shortened to PLC in Russian descriptions and PLC in English. A modern controller may have a fairly powerful Pentium-class processor, usually with low power consumption. Controllers can be specialized, designed to effectively solve a specific task (for example, a relay protection controller) or universal, which can solve diverse tasks in accordance with an established set of blocks and software options - for example, the task of taking readings from metering devices.

Controllers SIMATIC S 7 400 controller from SIEMENS SIMATIC S 7 300 controller from SIEMENS Micro controller. Octagon Systems PC

Actuators An actuator is a servo drive, a device designed to move a regulating body (the regulating body can be made in the form of a valve, flap, gate valve, faucet, gate valve, damper, etc.) in automatic control or remote control systems, as well as as an auxiliary drive elements of tracking systems, steering devices of transport vehicles, etc.

The classification of actuator mechanisms usually consists of a motor, transmission, and control elements, as well as feedback, alarm, blocking, and shutdown elements. I. m. for regulating the flow of liquids and gases is a valve, valve or gate moved by a hydraulic, pneumatic or electric drive. In pneumatic actuators, the adjustment force is created by the action compressed air onto the diaphragm, piston or bellows. In accordance with this, mechanical pumps are structurally divided into membrane piston bellows

Classification of actuators In hydraulic actuators, the adjustment force is created by the action of fluid pressure on a membrane, piston or blade. In accordance with this, mechanical pumps are structurally divided into membrane piston bladed

Classification of actuators A separate subclass of hydraulic motors consists of hydraulic motors with fluid couplings. Diaphragm and piston pneumatic and hydraulic immobilizers are subdivided into springless immobilizers. In spring immobilizers, adjustment forces in one direction are created by the pressure in the working cavity of the immobilizer, and in the opposite direction, elastic layers of a compressed spring. In springless immobilizers, the working pressure on the piston or membrane acts on both sides of the piston or membrane. Electric motors are characterized by: a) a variety of types of electric motors; b) ease of nutrition in industrial conditions; c) ease of obtaining high speeds.

Classification of actuators Based on the principle of operation, electric motors are divided into electric motor electromagnetic and, based on the nature of the movement of the output organ, they are divided into linear (translational motion) rotary (rotational motion) rotary, in turn, divided into single-turn multi-turn

HART protocol Data exchange between the control system and intelligent primary sensors is easily accomplished using the standard HART® (Highway Addressable Remote Transducer) communication protocol. The HART protocol uses the principle of frequency modulation to exchange data at a speed of 1200 baud. To transmit a logical "1", HART uses one full period frequency 1200 Hz, and to transmit logical “0” two incomplete periods of 2200 Hz. The HART component is superimposed on the 4-20 mA current loop. Since the average value of the sine wave over the period is “0”, the HART signal does not affect the analog signal 4-20 mA. The HART protocol is built on the “master-slave” principle, that is The field device responds to the system request. The protocol allows for two control devices (control system and communicator).

HART Architecture The HART protocol can be used in two connection modes. One is a point-to-point connection, and is used in systems with one slave and a maximum of two masters. The master device can be a site communication device or a programmable logic controller. As a secondary one – a HART terminal or any other device with a HART modem. Information can be transferred in both directions, and the transfer of analog information over the same channel is not interrupted. The second type of connection – “bus” – involves connecting up to 15 slave devices with the same two master devices. In this case, only data is exchanged in digital form. Moreover, an additional current source is provided in the controller circuit, providing 4 mA for each consumer.

HART protocol commands Protocol commands are divided into three main groups: Universal – basic commands supported by slave devices. Used to read standard parameters common to all devices, such as device type, measurement range, current value, etc. Standard – commands used in almost all HART devices. Configure the operation of devices. For example, writing/reading standard and instrument parameters. Specific – commands for setting specific, individual parameters of a device, for example, calibrating an ultrasonic sensor or reading basic device data.

HART Commands 1. Universal ¢ Read Manufacturer and Device Type ¢ Read Main Variable (MV), Units ¢ Read Current Value and Percent of Range ¢ Read Up to Four Predefined Variables ¢ Read/Write 8 Character Identifier and 16 Character Description ¢ Read /write 32 character message ¢ Read device value range, units. measurements and sampling time ¢ Read serial number sensor and restrictions ¢ Read/write the last code of the device set ¢ Write the request address

HART Commands 2. Standard ¢ ¢ ¢ ¢ Read a sample of up to four dynamic variables Write a sample time constant Write the device range Calibrate (set zero, span) Set output current constant Perform self-test Perform restart Set GPU to zero Write GPU units Set the zero value of the DAC and coefficient. gain Write conversion function (square root, etc.) Write sensor serial number Read/write dynamic variable settings

Ethernet network technology Network technology is a coordinated set of standard protocols and hardware that implements them (for example, network adapters, drivers, cables and connectors), sufficient to build a computer network. Sometimes network technologies are called basic technologies, meaning that the basis of any network is built on their basis. Ethernet standard was adopted in 1980. The number of networks built on the basis of this technology is currently estimated at 5 million, and the number of computers working in such networks is 50 million. The basic principle underlying Ethernet is a random method of accessing a shared data transmission medium.

HART Commands 3. Device Specific Commands ¢ ¢ ¢ Read/Write Trim Level Start, Stop or Master Reset Read/Write Calibration Accuracy Factor Read/Write Materials and Construction Information Calibrate Sensor Enable PID Set PID Setpoint Characteristic Valve Setpoint Valve Motion Limits User Units Local Display Information

Advantages of Ethernet ¢ ¢ ¢ The main advantage of Ethernet networks that has made them so popular is their cost-effectiveness. In addition, Ethernet networks implement fairly simple algorithms for accessing the medium, addressing and transmitting data. The simplicity of the logic of network operation leads to simplification and, accordingly, cheaper network adapters and their drivers. For the same reason, Ethernet network adapters are highly reliable. And finally, another remarkable property of Ethernet networks is their good expandability, that is, the ease of connecting new nodes.

Production automation tools include technical automation equipment (TAA) - these are devices and instruments that can either themselves be automation tools or be part of a hardware and software complex. Security systems on modern enterprise include technical means of automation. Most often, TCA is the basic element of the system integrated security.

Technical automation equipment includes devices for recording, processing and transmitting information in automated production. With their help, automated production lines are monitored, regulated and controlled.

Safety systems monitor the production process using a variety of sensors. They include pressure sensors, photo sensors, inductive sensors, capacitive sensors, laser sensors, etc.

Sensors are used to automatically extract information and convert it initially. Sensors differ in their principles of operation and in their sensitivity to the parameters they monitor. Technical safety equipment includes the widest range of sensors. It is the integrated use of sensors that makes it possible to create comprehensive security systems that control many factors.

Technical means of information also include transmitting devices that provide communication between sensors and control equipment. Upon receiving a signal from the sensors, the control equipment pauses the production process and eliminates the cause of the accident. If it is impossible to eliminate the emergency situation, technical safety equipment gives a signal about the malfunction to the operator.

The most common sensors that are included in any integrated security system are capacitive sensors.

They allow contactless detection of the presence of objects at a distance of up to 25 mm. Capacitive sensors operate according to the following principle. The sensors are equipped with two electrodes, between which conductivity is recorded. If any object is present in the control zone, this causes a change in the oscillation amplitude of the generator included in the sensor. At the same time, capacitive sensors are triggered, which prevents unwanted objects from entering the equipment.

Capacitive sensors are distinguished by their simplicity of design and high reliability, which allows them to be used in a wide variety of production areas. The only drawback is the small control area of ​​such sensors.

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Industrial Safety
In most modern automated enterprises, industrial safety is ensured through the implementation complex systems safety and production control