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Development of a project for numerical simulation of the technological process. Process modeling

MINISTRY OF EDUCATION AND SCIENCE OF RUSSIA

Federal State Budgetary Educational Institution

NIZHNEVARTOVSK OIL COLLEGE (branch)

federal state budget educational institution

higher education

MDK 04.01 " Theoretical basis development and modeling of simple automation systems, taking into account the specifics of technological processes"

Guidelines on a course project

for students educational institutions

secondary vocational education

all forms of education (full-time, part-time)

by specialty 15.02.07. Automation of technological processes and production

Nizhnevartovsk 2016

Considered

At a meeting of the PCC ETD

Minutes No. 5 dated 24.05.2016

Chairman of the PCC

M. B. Ten

APPROVE

Deputy director for water resources management

NNT (branch) FGBOU VO "YUGU"

R.I. Khaibulina

« » 2016

Corresponds to:

1. Federal state standard (FSES) in the specialty 15.02.07. Automation of technological processes and production (by industry) approved on April 18, 2014 (Order No. 349)

Developer:

Ten Marina Borisovna, higher qualification category, teacher of the Nizhnevartovsk Oil College (branch) FGBOU VO "South State University".

INTRODUCTION

Guidelines for the course project on MDK 04.01 "Theoretical foundations for the development and modeling of simple automation systems, taking into account the specifics of technological processes" for full-time and part-time students are developed in accordance withrequirements of the Federal state standard(FGOS) in the specialty 15.02.07. Automation of technological processes and production (by industry), work program professional module PM 04Development and modeling of simple automation systems, taking into account the specifics of technological processes

The course project aims to consolidate and systematize the knowledge of students, develop skills in independent work and teach them to practically apply their theoretical knowledge in solving problems. production and technical character.

Didactic goals course design are: student learning professional skills; deepening, generalization, systematization and consolidation of knowledge on MDT; formation of skills and abilities of independent mental work; comprehensive verification of the development of professional and general competencies.

This manual aims to assist students in the implementation of the course project on MDK 04.01 "Theoretical foundations for the development and modeling of simple automation systems, taking into account the specifics of technological processes"

The course project is carried out after studying the theoretical part of the MDK 04.01 "Theoretical foundations for the development and modeling of simple automation systems, taking into account the specifics of technological processes"

The purpose of the course project is to master the methods of developing and modeling automatic control systems, plotting time and frequency characteristics and researching automatic control systems, as well as acquiring skills in using technical literature, reference books, normative documents. Work on a course project contributes to the systematization, consolidation, deepening of the knowledge gained by students in the course of theoretical training, the application of this knowledge for a comprehensive solution of the tasks. As a result of the course project, students should master professional competencies:

PC 4.1 Analyze automatic control systems, taking into account the specifics of technological processes.

PC 4.2 Select devices and automation tools, taking into account the specifics of technological processes.

PC4.3 Draw up diagrams of specialized units, blocks, devices and automatic control systems.

PC 4.4 Calculate the parameters of typical circuits and devices

The subject of the course project is selected in accordance with the place of internship

2 STRUCTURE of the course project

The course project consists of two parts: explanatory note and graphic part.

The structure of the explanatory note:

title page;

list of sheets of the graphic part;

scroll symbols and accepted abbreviations;

introduction;

Chapter 1;

chapter 2;

chapter 3;

conclusion;

bibliographic list;

applications.

The graphic part consists of two sheets of A1 format, while drawings and diagrams can be developed on A1 or A2 format, a specific set of graphic part is determined in an individual assignment and may include the following diagrams and drawings:

functional automation scheme;

external wiring diagram;

circuit diagrams;

wiring diagrams;

block diagram of the controller.

3 CONTENT OF THE COURSE PROJECT

Introduction

Introductioncontains the following sections:

A.Relevance of the project topic(justification of the need to study issues related to the subject of research), for exampleThe relevance of creating automated control systems has increased significantly, due tocthe cost of maintaining maintenance personnel and maintaining the environment environment ;

b.An object -(a set of connections and relations of properties that exists objectively in theory and practice and serves as a source of information necessary for the researcher). The object of research is the phenomenon or process of objective reality, to which the research activities subject, for example, for the topic “Development of a systemautomation of ESP, SRP and AGZU wells on a well cluster”, the object will be a well cluster;

V.Itemresearch (more specific and includes only those connections and relationships that are subject to direct study in this project, sets the boundaries of scientific research). In each object, several subjects of study can be distinguished, but one subject of study must be indicated in the work. The subject of the study is determined by the specific properties of the object, for example, for the topic “Development of a systemautomation of ESP, SRP and AGZU wells on a well cluster”, the subject will be ESP, SRP and AGZU wells;

From the subject of the study, its purpose and objectives follow.

G.Target (is formulated briefly and extremely precisely, in a semantic sense expressing the main thing that the researcher intends to do).

Examples: 1.The goal of the project is to develop an automation system based on optimally suitable automation tools. Modeling a sustainable and high-quality automatic control system

The purpose concretizes and develops in the tasks of the study.

The task must be formulated using an infinitive verb, for example: develop, analyze, identify, etc.

First task, as a rule, is associated with the identification, clarification, deepening, methodological justification of the essence, nature, structure of the object under study. For example, analyze the purpose of objects and develop a block diagram of a well cluster

Second- with an analysis of the real state of the subject of research, dynamics, internal contradictions of development. For example, to analyze the technology of work and the main technical characteristics of the AGZU, to determine the parameters of automation and the operating conditions of automation equipment.

Third and fourth- with methods of transformation, modeling, verification, or with the identification of ways and means to increase the efficiency of improving the phenomenon, process under study, i.e. with practical aspects of work, with the problem of managing the object under study. For example, develop an automation scheme, determine ways external connections automation equipment, explore methods of installation, repair, verification of automation equipment, determine economic efficiency

Research methodsinclude the use of specific theoretical and empirical research methods, for example: analysis of scientific and methodological literature, documentary sources, etc.

Structure and scope of work(indicate from which structural

The work consists of elements: introduction, number of chapters, paragraphs, conclusion, bibliographic list, indicating the number of titles, as well as the amount of work in pages, etc.).

The volume of the introduction is 2-3 pages.

2 CHARACTERISTICS OF THE ELEMENTS OF THE AUTOMATIC REGULATION SYSTEM (ACS)

2.1 Technological characteristics of the object of regulation

In this subsection of the course project, it is necessary to briefly outline the technology and the main technological characteristics the considered object of regulation.

2.2 Mathematical model object of regulation

It is necessary to draw the transient response of the regulated object according to the variant on a given scale.

According to the type of transient response, it is necessary to determine which typical dynamic links the object of regulation corresponds to by dynamic properties. Write down the transfer function of these links and determine the numerical values of the coefficients from the graph.

For example:

According to the experimentally taken transient response (Figure 2.1), we determine the transfer function of the control object.

The object of regulation corresponds to the serial connection of several aperiodic links and the delay link, so its transfer function

Рτ , (2.1)

To determine the numerical values of the coefficientsK 1 , T 1 , τ 1 according to the graph we find the steady value of the adjustable parameterh mouth, h mouth = 14. Let's switch to relative units, taking the valueh mouth for 1, divide the resulting segment into ten equal parts, mark the points a = 0.7,i=0.3. Determine the time corresponding to these points according to the schedulet i=9.8 and t A =11.8. Accept valuem=3.

According to table 7.8, we determine the value of the constant coefficients T a *, A ia, IN ia, for a=0.7 and i=0.3 depending on the degreemtransfer function

m = 3,

T 7 * = 0.277,

A 37 \u003d 1.125,

B 37 = 1.889.

Determine the delay time of the regulated object

, (2.2)

Determine the time constant of the regulated object

(2.3)

T 1 = 0,277 (11,8 – 9,8) = 1,19

Determine the gain of the regulated object

in
(2.4)

Whereh mouth - the steady value of the regulated value.

Since we are given a transient response, then X in = 1, so

K 1 = h mouth , (2.5)

K 1 =14

As a result, we obtain the OR transfer function in the form

-7.5r

2.3 Determination of optimal controller settings

In accordance with the given control law (initial data), it is necessary to determine the transfer function of the automatic controller and calculate the settings.

For example:

According to the initial data, the regulation law is proportional.

The equation of the regulation law has the form:

y = Kε (2.6)

Wherey - output value;

K - gain;

ε is the mismatch.

Let us write the regulation law in general view:

X out = K 2 X in (2.7)

Let's define the transfer function of the automatic controllerW 2 (p)

X out (p) \u003d K 2 X in (p)

W 2 (p) = K 2 (2.8)

We determine the controller settings according to the VTI formulas (table 7.13):

Object characteristic:

(2.9)

We define the limit of proportionality:

δ = 2 K 1 , (2.10)

δ \u003d 2 * 14 \u003d 28

Determine the gain of the automatic controllerK 2 :

(2.11)

As a result, we obtain the transfer function AR in the form

W 2 (p)=0,035

2.4 Mathematical model of the actuator and measuring transducer

AC electric motors are widely used as actuators in ACS. In systems where speed control of the actuator is required, three-phase asynchronous electric motors with a phase rotor are used. If speed control is not required, then electric motors with a squirrel-cage rotor are used. Two-phase asynchronous motors are widely used as low power actuators. The dynamic properties of asynchronous electric motors are determined by the differential equation

(2.12)

where T m – electromechanical time constant of the electric motor, s;

TO R - the transmission coefficient of the electric motor;

U R – voltage on the rotor, V;

Q is the angular velocity of the rotor, rad/s.

Electromechanical time constant T m depending on the inertia OR can be within T m =0.006÷2 s. In a course project, for example, we take T m = 2s.

According to the initial data, for example, K R =4, thus the IM transfer function:

(2.13)

The measuring transducer in terms of dynamic properties corresponds to the amplifying link. His equation:

X out \u003d KX in (2.14)

Gain K = 1, hence the transfer function of the IP:

W 5 (p)=1 (2.15)

3 STRUCTURAL DIAGRAM OF THE AUTOMATIC REGULATION SYSTEM

3.1 Regulation technological process

It is necessary to select the types of ATS elements, provide a description of their principle of operation, specifications. Describe the operation of the automatic control system.

3.2 Structural diagram of an open automatic control system for master and disturbing influences

It is necessary to develop a block diagram of the automatic control system for the driving and disturbing influences. Determine the transfer function of the open system.

For example.

Figure 3.1 - Block diagram

We calculate the transfer function of series-connected elements

Transfer function of the open ACS according to the master action

(3.1)

Transfer function of an open ACS for disturbing action

(3.2)

3.3 Structural diagram of a closed system of automatic control by master and disturbing influences

Let's determine the transfer function of a closed ACS according to the driving influence (Figure 3.1):

(3.3)

Let us determine the transfer function of a closed ACS according to the perturbing effect (Figure 3.1):

(3.4)

4 STABILITY OF THE AUTOMATIC REGULATION SYSTEM

4.1 Stability according to the Hurwitz criterion. Critical Gain

According to the Hurwitz criterion, the system is stable if for a 0 >0 the Hurwitz determinants are positive. Let the characteristic equation of the considered system

3.36r 4 +10.14r 3 +11.37r 2 +5.57r+2.17=0

We calculate the Hurwitz determinants

Δ 1 \u003d 10.14

Conclusion: The system is stable.

We determine the boundary gain by the Hurwitz criterion.

We replace the gain factors with letter designations.

W 2 (p)= K 2

W 3 (p)= K 3

W 5 (p)= K 5

We calculate the transfer function of the ACS.

Thus, the characteristic equation of the system has the form:

K 2 K 1-5 =0

Let's make a replacement K 2 K 1-5 = K gr.

3.36r 4 +10.14r 3 +11.37r 2 +5.57r+1+ K gr =0

We compose the Hurwitz determinant:

The system is on the stability boundary if one of the Hurwitz determinants is equal to 0.

From the resulting expression, we determineK gr.

642,17-102,81-102,81 K gr -104.24=0

102,81 K gr = -435.12

K gr = 4.23

Thus the critical gainK gr = 4.23.

4.2 Stability according to the Mikhailov criterion. Critical Gain

According to the Mikhailov criterion, the system is stable if the Mikhailov hodograph passes sequentially counterclockwisen-quarters of the complex plane when changing ω=0 ÷ +
. Let the characteristic equation of the system:

3.36r 4 +10.14r 3 +11.37r 2 +5.57r+2.176=0

Polinom Mikhailova:

Given the values ω=0 ÷ +
building a Mikhailov hodograph.

The calculation must be done programmatically. For example usingEXEL. Let's create a program for this example.

B2=3.36*B1^4-11.37*B1^2+2.176

B3=-10.14*B1^3+5.57*B1

Table 4.1 - Calculation results

The hodograph must be built using the software environment.

Figure 4.1 - Mikhailov's hodograph

Conclusion: the system is stable.

We determine the boundary coefficient according to the Mikhailov criterion.

The characteristic equation for unknown gains has the form:

3.36r 4 +10.14r 3 +11.37r 2 +5.57r+1+ K gr =0

The Mikhailov polynomial is equal to:

F(jω)

The system is on the stability boundary if the Mikhailov hodograph passes through the origin at a frequency ω≠0. Therefore, the system is on the stability boundary if the real and imaginary parts are equal to 0.

4.3 Stability according to the Nyquist criterion. Amplitude and phase stability margin

In order for the system to be stable in a closed form, it is necessary and sufficient that the AFC hodograph of a stable open system does not cover a point on the complex plane with coordinates

(-1;0) when changing ω=0 ÷ +0. An open system is considered stable if it consists of stable standard links.

Let the transfer function of the open system.

We define AFC:

Asking for values
we build the AFC of an open system usingexcel:

Table 4.2 - Calculation results

Figure 4.3 - Hodograph AFC

Conclusion: the system is stable

The margin of stability in amplitude and phase is determined by the hodograph of the AFC of an open system

Amplitude stability margin ΔА=0.74

Phase stability margin Δφ=130 0

5 QUALITY ACS

5.1 Transition graph

The graph of the transient process can be constructed using the trapezoid method. To do this, it is necessary to determine the AFC of a closed system, highlight the actual frequency response, plot the DFC. Then perform the operations in the following sequence.

Let's consider the construction of a graph of the transient process using an example.

We determine the AFC of a closed system:

Building a DCH graph

Table 5.1 - Results of DFC calculation

We divide the DFC into trapezoids so that two sides of each trapezoid are parallel to the ω axis, the third coincides with the P axis.

Figure 5.1 - Actual frequency response

We determine for each trapezoid ω 0 , ω d , h 0.

For example, 1 trapezoid: ω 0 =0,54.

ω d =0 ,31

h 0 =45,5

We calculate the X value for each trapezoid:

According to the X value, we find the values \u200b\u200bin the tableh x functions, given by the values of τ, for each trapezoid.

Automation and control systems are often complex and expensive. Therefore, carrying out physical experiments on them is impossible or impractical. In research existing systems have to rely on the results of observations of their behavior, and when creating new system- use analogies or supposed data about its functioning.

An output that allows you to get quantitative estimates, is the implementation of modeling, that is, the development and study of such models that, in terms of basic parameters, reflect the behavior of real systems.

To develop a control algorithm, instead of a real control object, its model is used. A model is an object of any physical nature that is capable of replacing any original object under study so that the study of the model (a more accessible object) provides new knowledge about the original. The meaning of the model is that it is always simpler in one way or another, more accessible than the original. The model should reflect only some of the features and properties of the original, essential for obtaining an answer to the question of interest to researchers.

The study of any properties of the original by building a model and studying its properties is called modeling. Simulation is one of the most common ways to study various processes and phenomena. The success of the study, the reliability of the result obtained with its help, depends on how well the model is chosen.

Modeling is physical and mathematical. In physical modeling, the model reproduces the process under study (original) while preserving its physical nature (for example, military exercises, a model of a hydroelectric power station, a business game, a laboratory installation). Between the original and the model, some similarity relationships are preserved, which are studied by the theory of similarity.

Mathematical modeling is understood as the development of mathematical models and the study of some properties of the original with their help. A mathematical model is a system of mathematical relationships that describe the object under study.

Mathematical modeling has found wide application in control theory.

The created mathematical model can become the subject of objective study. Knowing its properties, we thereby learn the properties of the real system reflected by the model.

With the help of the model, problems related to the behavior of the real system under study are sequentially considered and solved:

- description of system behavior,
- explanation of system behavior,
- prediction (forecast) of the behavior of the system.

Based on the solution of these problems, recommendations are developed for managing the system or for creating systems with a certain behavior.

In control theory, methods of statistical modeling of systems are widely used, especially in cases where the system is influenced by a very large number of random factors.

Obtaining solutions with the help of models is associated, as a rule, with a significant amount of calculations. These difficulties are resolved with the widespread use of computer technology, software and special methods.

The methods of control theory synthesize the achievements of mathematics (especially those sections of it, such as the theory differential equations, operational calculus, stability theory, mathematical programming, game theory, probability theory and mathematical statistics, etc.) and informal methods in the practice of designing and creating automatic control systems.

The practice of automation and control stimulates the development and improvement of various branches of mathematics. At the same time, the improvement of mathematical methods has a great influence on the practice of automation and control. At the same time, the well-known limitations of formal methods stimulate the development of various informal methods and procedures (for example, the method expert assessments, simulation, operation games, etc.).

When formulating the goal (strategy) of management, the characteristics of the technological process or object must first be studied and taken into account. often on her own automated system control is used as a tool for studying the course of the process and its reactions to control actions. Based on the theoretical and experimental data obtained as a result of such a study, a model of the technological process can be developed. It describes the process mathematically, allowing, with the help of computational tools, to obtain a fairly complete picture of the process as a whole. Based on the new process model, the required optimal control actions can be determined.

From the model of the process or control system, you can determine the parameters in the control algorithms.

Automation and simulation of the technological process

1 PROCESS AUTOMATION

Automation is a direction in the development of production, characterized by the liberation of a person not only from muscular efforts to perform certain movements, but also from the operational control of the mechanisms that perform these movements. Automation can be partial or complex.

Integrated automation is characterized by the automatic execution of all functions for the implementation of the production process without direct human intervention in the operation of the equipment. The responsibilities of a person include setting up a machine or group of machines, turning it on and controlling it. Automation is the highest form of mechanization, but at the same time it is new form production, not a simple replacement manual labor mechanical.

With the development of automation, industrial robots (IR) are increasingly being used, replacing a person (or helping him) in areas with dangerous, unhealthy, difficult or monotonous working conditions.

An industrial robot is a reprogrammable automatic manipulator for industrial applications. Characteristic features PRs are automatic control; the ability to quickly and relatively easy reprogramming, the ability to perform labor actions.

It is especially important that PR can be used to perform work that cannot be mechanized or automated by traditional means. However, PR is just one of many possible means of automating and simplifying production processes. They create the prerequisites for the transition to a qualitatively new level of automation - the creation of automatic production systems working with minimal human intervention.

One of the main advantages of PR is the ability to quickly change over to perform tasks that differ in the sequence and nature of manipulation actions. Therefore, the use of PR is most effective in conditions of frequent change of production facilities, as well as for the automation of low-skilled manual labor. Equally important is the provision of quick changeovers. automatic lines, as well as their assembly and launch in a short time.

Industrial robots make it possible to automate not only basic, but also auxiliary operations, which explains the ever-growing interest in them.

The main prerequisites for expanding the use of PR are as follows:

improving the quality of products and the volume of its output with the same number of employees due to the reduction in the time of operations and the provision of a constant “fatigue-free” mode, an increase in the shift ratio of equipment, intensification of existing and stimulation of the creation of new high-speed processes and equipment;

changing the working conditions of workers by freeing them from unskilled, monotonous, heavy and harmful labor, improving safety conditions, reducing the loss of working time from industrial injuries and vocational diseases;

economy of labor power and release of workers for the solution of national economic problems.

1.1 Construction and calculation of the scheme of the model "hard terminal - hole printed circuit board»

An essential factor in the implementation of the assembly process is to ensure the assembly of the electronic module. Collectability depends in most cases on the accuracy of positioning and the effort required to assemble the structural elements of the module, structurally technological parameters mating surfaces.

In the variant when a hard lead is inserted into the board hole, the following can be distinguished: characteristic species contact of mating elements:

non-contact output passage through the hole;

contact of the zero type, when the end of the output touches the generatrix of the chamfer of the hole;

contact of the first type, when the end of the output touches the side surface of the hole;

contact of the second kind, when the side surface of the output touches the edge of the chamfer of the hole;

contact of the third type, when the end of the output touches the side surface of the hole, and the output surface touches the edge of the chamfer of the hole.

The following are accepted as classification signs for distinguishing types of contacts: a change in the normal reaction at the point of contact; friction force; the shape of the elastic line of the rod.

The tolerances of individual elements have a significant influence on the reliable operation of the setting head. In the positioning and movement processes, a chain of tolerances occurs, which in unfavorable cases can lead to an error in the installation of the ERE, leading to a poor assembly.

The assembly of the product depends, therefore, on three factors:

dimensional and accuracy parameters of the mating surfaces of the product components;

dimensional and accuracy parameters of the mating surfaces of the base element of the product;

dimensional and precision positioning parameters of the executive body with the component located in it.

Consider the case of a zero-type contact, the diagram of which is shown in Figure 1.1.

Figure 1.1 - Calculation scheme of the contact of the zero type.

Initial data:

F is the assembly force directed along the head;

f is the coefficient of friction;

Rg is the reaction of the assembly head, perpendicular to its course;

N is the reaction normal to the chamfer forming;

Mg - bending moment relative to the assembly head;

Not only decrease, for example, by improving the culture of production and the use of environmentally more advanced equipment and technologies, but also increase, for example, with the introduction of new technological processes, such as flue gas desulfurization and denitrification. waste water- this is water, the properties of which have been changed as a result of domestic, industrial, agricultural or ...

To complex shaping equipment and tools. Another important task of the Chamber of Commerce and Industry is the management of the processes of the Chamber of Commerce. Automation of CCI process management allows for efficient complete solution all pre-production tasks. Work on the technological preparation of production is carried out by the relevant divisions and services of the enterprise. As a rule, the largest amount of work and the total...

At one or more workplaces, lengthening production lines, the use of mechanized group and standard processes. The proportionality of production processes must be restored all the time with their consistent improvement, associated with an increase in the level of mechanization and automation. At the same time, an increase in proportionality should be achieved on the basis of an ever higher ...

BIOREACTOR Sheet 90 Report. Dear members of the State Examination Commission, let me present to your attention a thesis project on the topic: "Automated control system for the sterilization process of a bioreactor" The sterilization process of a bioreactor (or fermenter) is an important stage in the process of biosynthesis of the antibiotic erythromycin. The essence of the sterilization process is...

Automation and simulation of the technological process

1 PROCESS AUTOMATION

Integrated automation is characterized by the automatic execution of all functions for the implementation of the production process without direct human intervention in the operation of the equipment. The responsibilities of a person include setting up a machine or group of machines, turning it on and controlling it. Automation is the highest form of mechanization, but at the same time it is a new form of production, and not a simple replacement of manual labor with mechanical labor.

An industrial robot is a reprogrammable automatic manipulator for industrial applications. The characteristic features of PR are automatic control; the ability to quickly and relatively easy reprogramming, the ability to perform labor actions.

One of the main advantages of PR is the ability to quickly change over to perform tasks that differ in the sequence and nature of manipulation actions. Therefore, the use of PR is most effective in conditions of frequent change of production facilities, as well as for the automation of low-skilled manual labor. Equally important is the provision of quick readjustment of automatic lines, as well as their completion and commissioning in a short time.

Industrial robots make it possible to automate not only basic, but also auxiliary operations, which explains the ever-growing interest in them.

The main prerequisites for expanding the use of PR are as follows:

changing the working conditions of employees by freeing them from unskilled, monotonous, hard and hazardous work, improving safety conditions, reducing losses of working time from industrial injuries and vocational diseases;

economy of labor power and release of workers for the solution of national economic problems.

1.1 Construction and calculation of the scheme of the model "hard terminal - PCB hole"

An essential factor in the implementation of the assembly process is to ensure the assembly of the electronic module. Assemblability depends in most cases on the positioning accuracy and effort required to assemble the module structural elements, the design and technological parameters of the mating surfaces.

In the variant when a hard lead is inserted into the board hole, the following characteristic types of contact of the mating elements can be distinguished: