Technical means used in automated systems of enterprises. Systems and means of production automation. Technical means of automation. Automated control systems

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 manual, 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 integral part digital converters, primary displacement converters largely predetermine the parameters of the digital processing unit as a whole, since it is the first stage of the conversion, displacement - electrical parameter, that mainly determines such characteristics of the digital processing unit as accuracy, speed, linearity of control, etc. The main requirements that are presented during development and design to PP displacements: 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 of an electric charge on the surface of some materials at the moment 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 parameter of the output signal located in linear dependence depending on the measured displacement, continuous-action PPs 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. Distinguish following types instruments: indicating, recording, summing, direct action, comparisons. ¢ Accuracy class is a generalized characteristic of an SI, determined by the limits of permissible main and additional errors, as well as other properties of the 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 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. ¢ Check valve called 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 a working pressure of 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. AP is distinguished: partial, complex and complete.

Production automation methods ¢ First, they develop methods for effectively studying the patterns of control objects, their dynamics, stability, and the dependence of behavior on the influence of 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.

Production automation methods ¢ Thirdly, the task is to create engineering methods for the simplest, most reliable and effective implementation of the structure and design of automation equipment that performs the specified functions of measurement, processing of results and control. 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. Choice 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 designed for production automation. T.s. A. provide automatic receipt, transmission, transformation, comparison and use of information for the purpose of monitoring and managing 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 (thermal. 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 indicating equipment, regulators and other automation devices, control systems operating from a standard output signal of 4-20 m. A direct current. 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 devices is used, deposited by vacuum diffusion onto a sapphire plate (the so-called “silicon-on-sapphire” SOS structure) connected to 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 media 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: Н= 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 air environment, reflected from the boundary with a 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. As a result, the output is a mixture of signals, which is analyzed using special mathematical and software to highlight and maximize precise definition 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 the working tank, 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 inductive converter(UB EM), or a valve that blocks 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 process control systems 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 ones functionality, which were 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. The smart sensor has the ability to work with a wide variety of different types sensors, and also combine one or more measurements into one new measurement (for example, volume flow and temperature into weight 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 of compressed air on a membrane, 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 cycle of 1200 Hz, and to transmit a logical "0" two partial cycles 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 any 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 sensor serial number and restrictions ¢ Read/write latest device set code ¢ Write 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. The 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.

General information about process automation

Food production processes

Basic concepts and definitions of automation

Machine(Greek automatos - self-acting) is a device (a set of devices) that functions without human intervention.

Automation 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.

Goal of automation– increasing labor productivity, improving product quality, optimizing planning and management, eliminating people from working in conditions hazardous to health.

Automation is one of the main directions of scientific and technological progress.

Automation as an academic discipline, it is an area of ​​theoretical and applied knowledge about automatically operating devices and systems.

The history of automation as a branch of technology is closely connected with the development of automatic machines, automatic devices and automated complexes. In its infancy, automation relied on theoretical mechanics and the theory of electrical circuits and systems and solved problems related to regulating pressure in steam boilers, steam piston stroke and rotation speed electric machines, control the operation of automatic machines, automatic telephone exchanges, relay protection devices. Accordingly, technical means of automation during this period were developed and used in relation to automatic control systems. The intensive development of all branches of science and technology at the end of the first half of the 20th century also caused the rapid growth of automatic control technology, the use of which is becoming universal.

The second half of the 20th century was marked by further improvement of technical means of automation and wide, although uneven for different industries National economy, the spread of automatic control devices with the transition to more complex automatic systems, in particular in industry - from the automation of individual units to the complex automation of workshops and factories. A special feature is the use of automation at facilities that are geographically distant from each other, for example, large industrial and energy complexes, agricultural facilities for the production and processing of agricultural products, etc. For communication between individual devices in such systems, telemechanics are used, which, together with control devices and controlled objects, form teleautomatic systems. In this case, technical (including telemechanical) means of collecting and automatically processing information become of great importance, since many problems in complex automatic control systems can only be solved with the help of computer technology. Finally, the theory of automatic control gives way to a generalized theory of automatic control, which unites all theoretical aspects of automation and forms the basis general theory management.

The introduction of automation in production has significantly increased labor productivity and reduced the share of workers employed in various areas of production. Before the introduction of automation, the replacement of physical labor occurred through the mechanization of the main and auxiliary operations of the production process. Intellectual work remained non-mechanized for a long time. Currently, intellectual labor operations are becoming the object of mechanization and automation.

There are different types of automation.

1. Automatic control includes automatic alarm, measurement, collection and sorting of information.

2. Automatic alarm is intended to notify about limit or emergency values ​​of any physical parameters, about the location and nature of technical violations.

3. Automatic measurement provides measurement and transmission to special recording devices of the values ​​of controlled physical quantities.

4. Automatic sorting carries out control and separation of products and raw materials by size, viscosity and other indicators.

5. Automatic protection This is a set of technical means that ensure the termination of a controlled technological process when abnormal or emergency conditions occur.

6. Automatic control includes a set of technical means and methods for managing the optimal progress of technological processes.

7. Automatic regulation maintains the values ​​of physical quantities at a certain level or changes them according to the required law without direct human participation.

These and other concepts related to automation and control are united by cybernetics– the science of managing complex developing systems and processes, studying the general mathematical laws of controlling objects of various natures (kibernetas (Greek) – manager, helmsman, helmsman).

Automatic control system(ACS) is a set of control object ( OU) and control devices ( UU), interacting with each other without human participation, the action of which is aimed at achieving a specific goal.

Automatic control system(SAR) – totality OU and an automatic controller, interacting with each other, ensures that the TP parameters are maintained at a given level or changed according to the required law, and also operates without human intervention. ATS is a type of self-propelled gun.

Management, consulting and entrepreneurship

Lecture 2. General information about technical means of automation. Need to study general issues concerning technical means of automation 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 of technical support for 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(TCA) 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:

• collection of information about the current state of the technological control object (TOU);
• determination of quality criteria for TOU work;
• finding optimal mode functioning of the technical control system 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. Management information system structure:

D - sensor (primary measuring transducer);

VP - secondary indicating device;

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

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

IM actuator;

RO - regulatory body;

C - alarm devices;

MS mnemonic diagrams.

In some cases, the information control system includes direct-acting regulators 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 ACS is the automatic control system (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 automated control systems built on the basis of individual use TSA and a central computer computer (CUVM), which has an information communication line 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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The means of generating and primary processing of information include keyboard devices for applying data to cards, tapes or other information carriers by mechanical (punching) or magnetic methods; the accumulated information is transferred for subsequent processing or reproduction. Keyboard devices, punching or magnetic blocks and transmitters are used to make up production recorders for local and system purposes, which generate primary information in workshops, warehouses and other places of production.

Sensors (primary transducers) are used to automatically extract information. They are very diverse devices in terms of operating principles that sense changes in the controlled parameters of technological processes. Modern measuring technology can directly evaluate more than 300 different physical, chemical and other quantities, but this is not enough to automate a number of new areas of human activity. An economically feasible expansion of the range of sensors in the GPS is achieved by unifying the sensitive elements. Sensitive elements that respond to pressure, force, weight, speed, acceleration, sound, light, thermal and radioactive radiation are used in sensors to control the loading of equipment and its operating modes, the quality of processing, accounting for the release of products, monitoring their movements on conveyors, stocks and consumption of materials, workpieces, tools, etc. The output signals of all these sensors are converted into standard electrical or pneumatic signals, which are transmitted by other devices.

Devices for transmitting information include signal converters into forms of energy convenient for broadcasting, telemechanics equipment for transmitting signals via communication channels over long distances, switches for distributing signals to places where information is processed or presented. These devices connect all peripheral sources of information (keyboard devices, sensors) with the central part of the control system. Their purpose is to effectively use communication channels, eliminate signal distortion and the influence of possible interference during transmission over wired and wireless lines.

Devices for logical and mathematical information processing include functional converters that change the nature, shape or combination of information signals, as well as devices for processing information according to given algorithms (including computers) in order to implement laws and control (regulation) modes.

Computers for communication with other parts of the control system are equipped with information input and output devices, as well as storage devices for temporary storage of source data, intermediate and final results of calculations, etc. (see Data input. Data output, Storage device).

Devices for presenting information show the human operator the state of production processes and record it the most important parameters. Such devices are signal boards, mnemonic diagrams with visual symbols on boards or control panels, secondary pointer and digital indicating and recording instruments, cathode ray tubes, alphabetic and digital typewriters.

Devices for generating control actions convert weak information signals into more powerful energy pulses of the required shape, necessary to activate protection, regulation or control actuators.

Ensuring high quality of products is associated with automation of control at all main stages of production. Subjective human assessments are replaced by objective indicators from automatic measuring stations linked to central points where the source of defects is determined and from where commands are sent to prevent deviations outside of tolerances. Of particular importance is automatic control using computers in the production of radio-technical and radio-electronic products due to their mass production and a significant number of controlled parameters. No less important are final reliability tests of finished products (see Reliability of technical devices). Automated stands for functional, strength, climatic, energy and specialized tests allow you to quickly and identically check the technical and economic characteristics of products (products).

Actuating devices consist of starting equipment, actuating hydraulic, pneumatic or electrical mechanisms (servomotors) and regulatory bodies that act directly on the automated process. It is important that their operation does not cause unnecessary energy losses and reduce the efficiency of the process. So, for example, throttling, which is usually used to regulate the flow of steam and liquids, based on increasing the hydraulic resistance in pipelines, is replaced by influencing the flow-forming machines or other, more advanced methods of changing the speed of flows without loss of pressure. Of great importance is the economical and reliable control of an alternating current electric drive, the use of gearless electric actuators, and contactless ballasts for controlling electric motors.

The idea of ​​constructing instruments for monitoring, regulation and control in the form of units consisting of independent blocks that perform certain functions, implemented in GSP, made it possible to various combinations using these blocks to obtain a wide range of devices for solving diverse problems using the same means. Unification of input and output signals ensures a combination of blocks with various functions and their interchangeability.

The GSP includes pneumatic, hydraulic and electrical devices and devices. Electrical devices designed to receive, transmit and reproduce information are the most versatile.

The use of a universal system of industrial pneumatic automation elements (USEPPA) made it possible to reduce the development of pneumatic devices mainly to assembling them from standard units and parts with a small number of connections. Pneumatic devices are widely used for control and regulation in many fire and explosion hazardous industries.

GSP hydraulic devices are also assembled from blocks. Hydraulic instruments and devices control equipment that requires high speeds to move control elements with significant effort and high precision, which is especially important in machine tools and automatic lines.

In order to most rationally systematize GSP facilities and to increase the efficiency of their production, as well as to simplify the design and configuration of automated control systems, GSP devices are combined into aggregate complexes during development. Aggregate complexes, thanks to the standardization of input-output parameters and block design of devices, most conveniently, reliably and economically combine various technical means in automated control systems and allow the assembly of a variety of specialized installations from general-purpose automation units.

Targeted aggregation of analytical equipment, testing machines, mass dosing mechanisms with unified measuring, computing and office equipment facilitates and accelerates the creation of basic designs of this equipment and the specialization of factories for their production.

Question 1 Basic concepts and definitions of A&C

Automation- one of the areas of scientific and technological progress that uses self-regulating technical means and mathematical methods with the aim of freeing people from participation in the processes of obtaining, converting, transferring and using energy, materials or information, or significantly reducing the degree of this participation or the complexity of the operations performed. Automation makes it possible to increase labor productivity, improve product quality, optimize management processes, and remove people from production processes that are hazardous to health. Automation, with the exception of the simplest cases, requires an integrated, systematic approach to solving a problem. Automation systems include sensors (sensors), input devices, control devices (controllers), actuators, output devices, and computers. The computational methods used sometimes copy the nervous and mental functions of humans. This entire complex of tools is usually called automation and control systems.

All automation and control systems are based on such concepts as a control object, a communication device with a control object, control and regulation of technological parameters, measurement and conversion of signals.

The control object is understood as a technological apparatus or a set of them in which standard technological operations of mixing, separation or their mutual combination with simple operations are carried out (or with the help of which are carried out). Such a technological apparatus, together with the technological process that takes place in it and for which an automatic control system is developed, is called a control object or an automation object. From the set of input and output quantities of a controlled object, controlled quantities, control and disturbing influences and interference can be distinguished. Controlled value is an output physical quantity or parameter of a controlled object, which during the operation of the object must be maintained at a certain specified level or changed according to a given law. Control action is a material or energy input flow, by changing which, it is possible to maintain the controlled value at a given level or change it according to a given law. An automatic device or regulator is a technical device that allows, without human intervention, to maintain the value of a technological parameter or change it according to a given law. An automatic control device includes a set of technical means that perform certain functions in the system. The automatic control system includes: Sensing element or sensor, which serves to convert the output value of the controlled object into a proportional electrical or pneumatic signal, Comparison element- to determine the magnitude of the discrepancy between the current and specified values ​​of the output value. Setting element serves to set the value of the process parameter, which must be maintained at a constant level. Amplifying-converting the element serves to generate a regulatory effect depending on the magnitude and sign of the mismatch due to an external energy source. Actuator element serves to implement regulatory influence. produced by UPE. Regulating element– to change the material or energy flow in order to maintain the output value at a given level. In automation practice During production processes, automatic control systems are equipped with standard general industrial devices that perform the functions of the above elements. The main element of such systems is a computer that receives information from analog and discrete sensors of technological parameters. The same information can be sent to analog or digital information presentation devices (secondary devices). The process operator accesses this machine using a remote control to enter information not received from automatic sensors, request necessary information and advice on process control. The work of the automated control system is based on the receipt and processing of information.

Main types of automation and control systems:

· automated planning system (APS),

· automated system of scientific research (ASNI),

· computer-aided design system (CAD),

· automated experimental complex (AEC),

· flexible automated production (GAP) and automated process control system (APCS),

· automated operation control system (ACS)

· automatic control system (ACS).

Question 2 Composition of technical means of automation and control of automated control systems.

Technical means of automation and control are devices and instruments that can either be automation tools themselves or be part of a hardware and software complex.

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

Technical means of automation and control 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.

Technical means of automation and control can be systematized as follows:

CS – control system.
Memory – Master device (buttons, screens, toggle switches).

UIO – Information display device.
UIO – Information processing device.

USPU – Converter / Amplifier device.
CS – Communication channel.
OU – Control object.
IM – Actuators.

RO – Working bodies (Manipulators).

D – Sensors.
VP – Secondary converters.

According to their functional purpose, they are divided into the following 5 groups:

Input devices. These include - ZU, VP, D;

Output devices. These include - IM, USPI, RO;

Devices of the central part. These include - UPI;

Industrial network tools. These include - KS;

Information display devices – UIO.

TSAiU perform the following functions: 1. collection and transformation of information about the state of the process; 2. transmission of information via communication channels; 3. transformation, storage and processing of information; 4. formation of management teams in accordance with the selected goals (criteria for the functioning of systems); 5. use and presentation of command information to influence the process and communicate with the operator using actuators. Therefore, all industrial means of automation of technological processes, based on their relationship to the system, are combined in accordance with the standard into the following functional groups: 1. means at the system input (sensors); 2. means at the output of the system (output converters, means for displaying information and process control commands, up to speech); 3. intra-system control systems (providing interconnection between devices with different signals and different machine languages), for example, have relay or open-collector outputs; 4. means of transmission, storage and processing of information.
Such a variety of groups, types and configurations of automated control systems leads to a multi-alternative problem of designing technical support for automated process control systems in each specific case. One of the most important criteria for choosing TSAiU can be their cost.

Thus, technical means of automation and control include devices for recording, processing and transmitting information in automated production. With their help, automated production lines are monitored, regulated and controlled.