Automation and modeling 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.

Complex automation is characterized by the automatic execution of all functions to carry out the production process without direct human intervention in the operation of the equipment. A person's responsibilities include setting up a machine or group of machines, turning it on and monitoring 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.

With the development of automation, industrial robots (IR) are increasingly 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 use. The characteristic features of PR are automatic control; the ability to quickly and relatively easily reprogram, 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 that operate with minimal human intervention.

One of the main advantages of PR is the ability to quickly changeover 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 changes of production facilities, as well as for the automation of manual low-skilled labor. Equally important is to ensure rapid readjustment of automatic lines, as well as their assembly and commissioning in a short time.

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

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

increasing the quality of products and the volume of their output with a constant number of workers due to reducing the time required to complete operations and ensuring a constant “fatigue-free” mode, increasing the shift ratio of equipment, intensifying existing and stimulating the creation of new high-speed processes and equipment;

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

saving labor and freeing up workers to solve national economic problems.

1.1 Construction and calculation of the “rigid lead – printed circuit board hole” model circuit

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

In the case where a rigid lead is inserted into the board hole, the following characteristic types of contact of the mating elements can be distinguished:

contactless output passage through the hole;

zero type contact when the end of the lead touches the chamfer of the hole;

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

contact of the second type, when the side surface of the lead touches the edge of the hole chamfer;

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

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

The reliable operation of the setting head is significantly influenced by the tolerances of individual elements. In the processes of positioning and movement, a chain of tolerances arises, which in unfavorable cases can lead to an error when installing the ERE, leading to poor-quality assembly.

The assembleability of the product thus depends on three factors:

dimensional and accuracy parameters of the mating surfaces of 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.

Let's consider the case of a zero-type contact, the diagram of which is shown in Figure 1.1.

Q

j

Figure 1.1 – Design diagram of a zero-type contact.

Initial data:

F – assembly force directed along the head;

f – friction coefficient;

Rg – reaction of the assembly head, perpendicular to its movement;

N – reaction normal to the chamfer generatrix;

Mg – bending moment relative to the assembly head;

Not only decrease, for example, due to improved production standards and the use of environmentally more advanced equipment and technologies, but also increase, for example, with the introduction of new technological processes, such as desulfurization and denitrification of flue gases. Waste water is water whose properties have been changed as a result of domestic, industrial, agricultural or...

To complex form-building equipment and tools. Another important task of the Chamber of Commerce and Industry is the management of Chamber of Commerce and Industry processes. Automation of CCI process management allows us to provide an effective comprehensive solution to all production preparation tasks. Work on technological preparation of production is carried out by the relevant departments and services of the enterprise. As a rule, the largest amount of work and overall...

At one or several workplaces, by lengthening production lines, using 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, increasing proportionality should be achieved on the basis of increasingly higher...

BIOREACTOR Sheet 90 Report. Dear members of the state examination commission, allow me to present to your attention a graduation project on the topic: “Automated control system for the bioreactor sterilization process.” The process of sterilization of a bioreactor (or fermenter) is an important stage in the biosynthesis process of the antibiotic erythromycin. The essence of the sterilization process is...

Automation and modeling 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.

Complex automation is characterized by the automatic execution of all functions to carry out the production process without direct human intervention in the operation of the equipment. A person's responsibilities include setting up a machine or group of machines, turning it on and monitoring 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.

With the development of automation, industrial robots (IR) are increasingly 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 use. The characteristic features of PR are automatic control; the ability to quickly and relatively easily reprogram, 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 that operate with minimal human intervention.

One of the main advantages of PR is the ability to quickly changeover 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 changes of production facilities, as well as for the automation of manual low-skilled labor. Equally important is to ensure rapid readjustment of automatic lines, as well as their assembly and commissioning in a short time.

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

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

increasing the quality of products and the volume of their output with a constant number of workers due to reducing the time required to complete operations and ensuring a constant “fatigue-free” mode, increasing the shift ratio of equipment, intensifying existing and stimulating the creation of new high-speed processes and equipment;

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

saving labor and freeing up workers to solve national economic problems.

1.1 Construction and calculation of the “rigid lead – printed circuit board hole” model circuit

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

In the case where a rigid lead is inserted into the board hole, the following characteristic types of contact of the mating elements can be distinguished:

contactless output passage through the hole;

zero type contact when the end of the lead touches the chamfer of the hole;

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

contact of the second type, when the side surface of the lead touches the edge of the hole chamfer;

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

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

The reliable operation of the setting head is significantly influenced by the tolerances of individual elements. In the processes of positioning and movement, a chain of tolerances arises, which in unfavorable cases can lead to an error when installing the ERE, leading to poor-quality assembly.

The assembleability of the product thus depends on three factors:

dimensional and accuracy parameters of the mating surfaces of 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.

Let's consider the case of a zero-type contact, the diagram of which is shown in Figure 1.1.

M G

R G

R F l

Q

j

Figure 1.1 – Design diagram of a zero-type contact.

Initial data:

F – assembly force directed along the head;

f – friction coefficient;

Rg – reaction of the assembly head, perpendicular to its movement;

N – reaction normal to the chamfer generatrix;

Mg – bending moment relative to the assembly head;

1.2 Design of the gripping device

Gripping devices (GD) of industrial robots are used to grab and hold objects to be manipulated in a certain position. When designing gripping devices, the shape and properties of the object being grabbed, the conditions of the technological process and the features of the technological equipment used are taken into account, which determines the variety of existing gripping devices of the PR. The most important criteria when evaluating the choice of grippers are adaptability to the shape of the object being grasped, grip accuracy and grip strength.

In the classification of gripping devices of the charger, the characteristics that characterize the object of capture, the process of capturing and holding the object, the technological process being served, as well as the signs reflecting the structural and functional characteristics and design basis of the charger are selected as classification ones.

Factors associated with the gripping object include the shape of the object, its mass, mechanical properties, aspect ratio, physical and mechanical properties of the object's materials, and surface condition. The mass of the object determines the required gripping force, i.e. load capacity of the PR, and allows you to select the type of drive and design base of the charger; the state of the surface of the object determines the material of the jaws with which the memory must be equipped; the shape of the object and the ratio of its dimensions also influence the choice of charger design.

The properties of the object's material influence the choice of method for capturing the object, the required degree of sensing of the memory, the possibility of reorienting objects in the process of capturing and transporting them to the technological position. In particular, for an object with a high degree of surface roughness, but non-rigid mechanical properties, it is possible to use only a “soft” clamping element equipped with sensors for determining the clamping force.

The variety of memory devices suitable for solving similar problems, and the large number of features characterizing their various design and technological features, do not allow constructing a classification on a purely hierarchical principle. Gears are distinguished according to the principle of operation: grasping, supporting, holding, capable of relocating an object, centering, basing, fixing.

Based on the type of control, memory devices are divided into: uncontrolled, command, hard-coded, adaptive.

Based on the nature of attachment to the PR hand, all memories are divided into: non-replaceable, replaceable, quick-change, suitable for automatic change.

All gripping devices are driven by a special device - a drive.

A drive is a system (electrical, electromechanical, electropneumatic, etc.) designed to drive the actuators of automated technological and production machines.

Main drive functions: force (power, torque), speed (set of speeds, speed range); the ability to maintain a given speed (force, torque) under conditions of load changes; speed, design complexity; efficiency, cost, dimensions, weight.

Basic requirements for drives. The drive must:

1) comply with all the main characteristics of the given technical specifications;

2) allow electrical remote automatic control;

3) be economical;

4) have a small mass;

5) provide simple coordination with the load.

According to the type of power energy used, drives are distinguished: electric, pneumatic, hydraulic, mechanical, electromechanical, combined.

Pneumatic drives use the energy of compressed air with a pressure of about 0.4 MPa, obtained from the workshop pneumatic network through an air preparation device.

1.2.1 Technical specifications for device design

At the technical specification stage, the optimal structural and layout solution is determined and technical requirements for equipment are drawn up:

1) name and scope of application – device for installing electrical electronics on a printed circuit board;

2) the basis for development - the assignment for the CCP;

3) the purpose and purpose of the equipment is to increase the level of mechanization and automation of the technological operation;

4) sources of development - using the experience of introducing technological equipment in the industry;

5) technical requirements:

a) the number of mobility steps is at least 5;

b) maximum load capacity, N 2.2;

c) static force at the operating point of the equipment, N not more than 50;

d) time between failures, hours, not less than 100;

e) absolute positioning error, mm +0.1;

f) speed of movement with maximum load, m/s: - along a free trajectory no more than 1; - along a straight path no more than 0.5;

g) the working space without equipment is spherical with a radius of 0.92;

h) pneumatic drive of the gripping device;

6) safety requirements GOST 12.1.017-88;

7) payback period 1 year.

1.2.2 Description of the design and operating principle of the industrial robot RM-01

The industrial robot (IR) RM-01 is used to perform various operations of folding, installation, sorting, packaging, loading and unloading, arc welding, etc. The general view of the robot is shown in Figure 1.2.

Figure 1.2 – Industrial robot RM-01

The robot manipulator has six stages of mobility. The manipulator links are connected one to another using joints that imitate the human elbow or shoulder joint. Each link of the manipulator is driven by an individual DC electric motor through a gearbox.

The electric motors are equipped with electromagnetic brakes, which allows you to reliably brake the manipulator links when the power is turned off. This ensures the safety of servicing the robot, as well as the ability to move its parts manually. PR RM-01 has a position-contour control system, which is implemented by the SPHERE-36 microprocessor control system, built on a hierarchical principle.

"SPHERE-36" has two levels of control: upper and lower. At the top level the following tasks are solved:

Calculation of algorithms for planning the trajectory of movement of the manipulator gripper and preparation of motion programs for each of its links;

Logical processing of information about the state of the device that makes up the robotic complex, and agreement to work as part of the robotic complex;

Exchange of information with a higher-level computer;

Interactive mode of operation of the operator using a video terminal and keyboard;

Read-write, long-term storage of programs using float drive;

Manual mode of manipulator control using a hand control panel;

Diagnostics of the control system operation;

Calibrating the position of the manipulator links.

At the lower control level, the tasks of processing specified movements by the manipulator links, which are formed at the upper level, are solved. Program positions are worked out at specified parameters (speed, acceleration) using digital electromechanical modules that drive the manipulator links. The control system consists of the following devices: central processing unit (CPM); RAM; ROM; an analog input module (MAV), where signals from potentiometric coarse computational position sensors are supplied; serial interface module (SIM); input/output module (IOM); communication module (MC).

Information exchange between top-level modules is carried out using the system bus.

The lower level of management has:

Drive processor modules (MPM);

Drive control modules (MCM).

The number of MPP and MUP modules corresponds to the number of manipulator links and is equal to 6. The MPP is connected to the communication module using system highways. The electric motors of the manipulator links are controlled using transistor pulse-width converters (PWC), which are part of the power supply unit (PSU). The MCP is based on the K1801 microprocessor and has:

Single-chip processor;

Initial start register;

System RAM, capacity 3216 – bit words; system ROM, with a capacity of 2x16-bit words;

Resident ROM with a capacity of 4x16 bit words;

Programmable timer.

The performance of the MCP is characterized by the following data:

Summation with register addressing means – 2.0 µs;

Summation with mediocre register addressing means – 5.0 µs;

Fixed point multiplication – 65 µs.

The operator panel is designed to perform operations on and off the PR, to select its operating modes.

The main elements of the panel are:

Mains power switch (NETWORK);

Emergency shutdown button (EMERGENCY). The mains power turns off when the button is pressed. The button is returned to its initial position by turning it clockwise;

Control system power button (CK1);

Control system power off button (CK0);

Drive power button (DRIVE 1). At the push of a button
the drive power is turned on, and at the same time the electromagnetic brakes of the motors are unlocked;

Drives power off button (DRIVE 0);

Mode selection switch. It has three positions ROBOT, STOP, RESTART. In ROBOT mode the system works normally. In STOP mode, program execution will stop at the end of the line step.

Moving the switch to ROBOT mode will continue the program execution to the beginning of the next step. RESTART mode is used to restart the execution of a user program from its first step;

Automatic start button (AUTOSTART). Pressing the button starts the system so that the robot begins executing the program without issuing commands from the keyboard. The button is pressed after the SC power is turned on. The mode is activated after turning on DRIVE 1.

The hand control panel is used to position the manipulator during teaching and programming. The remote control provides 5 operating modes:

Computer control of the manipulator (COMP);

Manual control in the main coordinate system (WORLD);

Manual control of degrees of mobility (JOINT);

Manual control in the tool coordinate system (TOOL);

Disabling mobility measure drives (FREE).

The selected mode is identified by a signal light.

The speed of movement of the manipulator is adjusted using the “SPEED”, “+”, “-” buttons. To compress and decompress the manipulator’s gripping device, use the “CLOSE” and “OPEN” buttons.

The "STER" button is used to record the coordinates of points when specifying a movement path. The "STOP" button, located at the end of the manual control panel, is intended to interrupt the execution of the program by turning off the power to the drives. Used to stop movement in normal situations. The "OFF" button has the same purpose as the "STOP" button. The difference is that the power to the manipulator drives is not turned off.

Moving the joints of the manipulator using the hand control panel is carried out in three modes: JOINT, WORLD and TOOL.

In the JOINT mode (selected by the corresponding button on the control panel), the user can directly control the movement of individual links of the manipulator. This movement corresponds to pairs of buttons “-” and “+”, respectively, for each link of the manipulator (i.e. column, shoulder, elbow, and three grip movements).

In WORLD mode, the system is actually fixed relative to the main coordinate system and moved in certain directions of this system (X, Y, Z, respectively).

It should be noted that work in the WORLD mode can be carried out at low speeds to avoid getting into the boundary of the robot's arm space. We also point out that the movement is provided automatically with the help of all links of the manipulator simultaneously.

TOOL mode provides movement in the active coordinate system.

A 12-bit line indicator is designed to display information about operating modes and errors:

NOKIA AOX - appears briefly upon startup;

ARMPWROFF - power to the manipulator drives is turned off;

MANUALMODE - allowed to control the robot from the control panel;

COMP MODE - the manipulator is computer-controlled;

LIMIT STOR - the joint is moved to the extreme position;

TOO CLOSE - the given point is very close to the manipulator;

FAR LLP - the specified point is outside the robot’s working area;

TEACH MOOE - the TEACH mode is activated, the manipulator follows arbitrary trajectories;

STEACH MODE - the STEACH-S mode is activated, the manipulator moves after straight-line trajectories;

ERROR - the buttons on the hand control are pressed at the same time, which constitute an illegal operation, etc..

In addition, the indicator of the selected speed with this encoding:

1 illuminated element - tool speed ≈ 1.9 mm/s;

2 illuminated element - tool speed ≈ 3.8 mm/s;

3 illuminated element - tool speed ≈ 7.5 mm/s;

4 illuminated element - tool speed ≈ 15.0 mm/s;

5 illuminated element - tool speed ≈ 30 mm/s;

6 illuminated element - tool speed ≈ 60 mm/s;

7 illuminated element - tool speed ≈ 120 mm/s;

8 illuminated element - tool speed ≈ 240 mm/s.

Below is an example of the control program PR RM-01 for drilling holes for surface mounting ERE:

G04 File: SVETOR~1.BOT, Thu Dec 01 21:35:19 2006*

G04 Source: P-CAD 2000 PCB, Version 10.15.17, (C:\DOCUME~1\Shepherd\WORKERS~1\SVETOR~1.PCB)*

G04 Format: Gerber Format (RS-274-D), ASCII*

G04 Format Options: Absolute Positioning*

G04 Leading-Zero Suppression*

G04 Scale Factor 1:1*

G04 NO Circular Interpolation*

G04 Millimeter Units*

G04 Numeric Format: 4.4 (XXXX.XXXX)*

G04 G54 NOT Used for Aperture Change*

G04 File Options: Offset = (0.000mm,0.000mm)*

G04 Drill Symbol Size = 2.032mm*

G04 Pad/Via Holes*

G04 File Contents: Pads*

G04 No Designators*

G04 No Drill Symbols*

G04 Aperture Descriptions*

G04 D010 EL X0.254mm Y0.254mm H0.000mm 0.0deg (0.000mm,0.000mm) DR*

G04 "Ellipse X10.0mil Y10.0mil H0.0mil 0.0deg (0.0mil,0.0mil) Draw"*

G04 D011 EL X0.050mm Y0.050mm H0.000mm 0.0deg (0.000mm,0.000mm) DR*

G04 "Ellipse X2.0mil Y2.0mil H0.0mil 0.0deg (0.0mil,0.0mil) Draw"*

G04 D012 EL X0.100mm Y0.100mm H0.000mm 0.0deg (0.000mm,0.000mm) DR*

G04 "Ellipse X3.9mil Y3.9mil H0.0mil 0.0deg (0.0mil,0.0mil) Draw"*

G04 D013 EL X1.524mm Y1.524mm H0.000mm 0.0deg (0.000mm,0.000mm) FL*

G04 "Ellipse X60.0mil Y60.0mil H0.0mil 0.0deg (0.0mil,0.0mil) Flash"*

G04 D014 EL X1.905mm Y1.905mm H0.000mm 0.0deg (0.000mm,0.000mm) FL*

G04 "Ellipse X75.0mil Y75.0mil H0.0mil 0.0deg (0.0mil,0.0mil) Flash"*

G04 D015 SQ X1.524mm Y1.524mm H0.000mm 0.0deg (0.000mm,0.000mm) FL*

G04 "Rectangle X60.0mil Y60.0mil H0.0mil 0.0deg (0.0mil,0.0mil) Flash"*

G04 D016 SQ X1.905mm Y1.905mm H0.000mm 0.0deg (0.000mm,0.000mm) FL*

G04 "Rectangle X75.0mil Y75.0mil H0.0mil 0.0deg (0.0mil,0.0mil) Flash"*

After drilling holes in the PCB, the robot installs the ERE. After installing the ERE, the board is sent for wave soldering.

2 MODELING OF THE TECHNOLOGICAL PROCESS

Modeling is a method of studying complex systems based on the fact that the system under consideration is replaced by a model and the model is studied in order to obtain information about the system under study. A model of the system under study is understood as some other system that behaves, from the point of view of the objectives of the study, similar to the behavior of the system. Usually, a model is simpler and more accessible for research than a system, which makes it easier to study it. Among the various types of modeling used to study complex systems, simulation modeling plays a large role.

Simulation modeling is a powerful engineering method for studying complex systems, used in cases where other methods are ineffective. A simulation model is a system that displays the structure and functioning of the original object in the form of an algorithm that connects input and output variables accepted as characteristics of the object under study. Simulation models are implemented in software using various languages. One of the most common languages ​​specifically designed for building simulation models is GPSS.

The GPSS (GeneralPurposeSystemSimulator) system is designed for writing simulation models of systems with discrete events. The GPSS system most conveniently describes models of queuing systems, which are characterized by relatively simple rules for the functioning of their constituent elements.

In GPSS, the system being modeled is represented by a set of abstract elements called objects. Each object belongs to one of the object types.

Each object type is characterized by a specific behavior and set of attributes defined by the object type. For example, if we consider the work of a port, loading and unloading arriving ships, and the work of a cashier in a movie theater, issuing tickets to patrons, we will notice great similarities in their functioning. In both cases, there are objects that are constantly present in the system (the port and the cashier) that process objects entering the system (ships and movie theater patrons). In queuing theory, these objects are called devices and requests. When processing of an incoming object ends, it leaves the system. If at the time of receipt of the request the service device is busy, then the request is placed in a queue, where it waits until the service device becomes free. A queue can also be thought of as an object whose function is to store other objects.

Each object can be characterized by a number of attributes that reflect its properties. For example, a service device has a certain productivity, expressed by the number of requests it processes per unit time. The application itself can have attributes that take into account the time it spent in the system, the time it waited in the queue, etc. A characteristic attribute of a queue is its current length, by observing which during operation of the system (or its simulation model), one can determine its average length during operation (or simulation). The GPSS language defines object classes with which you can define service devices, customer flows, queues, etc., as well as set specific attribute values ​​for them.

Dynamic objects, called transactions in GPSS, are used to specify service requests. Transactions can be generated during the simulation and destroyed (leave the system). The creation and destruction of transactions is performed by special objects (blocks) GENERATE and TERMINATE.

Messages (transactions) are dynamic GPSS/PC objects. They are created at certain points in the model, promoted by the interpreter through the blocks, and then destroyed. Messages are analogous to thread units in a real system. Messages can represent different elements even within the same system.

Messages move from block to block in the same way as the elements they represent (programs in the computer example) move.

Each promotion is considered an event that must occur at a specific point in time. The GPSS/PC interpreter automatically determines when events occur. In cases where an event cannot occur, although the time for its occurrence has approached (for example, when trying to occupy a device when it is already occupied), the message stops moving until the blocking condition is removed.

Once the system has been described in terms of the operations it performs, it must be described in GPSS/PC language using blocks that perform the corresponding operations in the model.

The user can define special points in the model at which statistics about queues need to be collected. Then the GPSS/PC interpreter will automatically collect statistics about queues (queue length, average time spent in queue, etc.). The number of delayed messages and the duration of these delays are determined only at these given points. The interpreter also automatically counts the total number of messages arriving at the queue at these points. This is done in much the same way as for devices and memories. Certain counters count the number of messages delayed in each queue, since the number of messages that pass any point in the model without delay may be of interest. The interpreter calculates the average time a message spends in the queue (for each queue), as well as the maximum number of messages in the queue.

2.1 Development of a block diagram and modeling algorithm

To model queuing systems, a general-purpose modeling system – GPSS – is used. This is necessary due to the fact that in the practice of research and design of complex systems, there are often systems that need to process a large flow of requests passing through servicing devices.

Models based on GPSS consist of a small number of operators, due to which they become compact and, accordingly, widespread. This is because GPSS has built-in the maximum possible number of logic programs required for modeling systems. It also includes special tools for describing the dynamic behavior of time-varying systems, with changes in state occurring at discrete moments in time. GPSS is very easy to program because the GPSS interpreter performs many functions automatically. Many other useful elements are included in the language. For example, GPSS maintains a simulation time timer, schedules events to occur later in the simulation time, causes them to occur on time, and manages the order of arrival.

To develop a block diagram, we will analyze the technological process of assembling the module being developed.

This technological process is characterized by sequential execution of technological operations. Therefore, the block diagram will look like a chain of sequentially connected blocks, each of which corresponds to its own technological operation and each of which lasts a certain time. The connecting links of these blocks are the queues formed as a result of each technological operation, and are explained by the different execution times of each of them. This block diagram is based on the design diagram for the assembly process of the designed module (Fig. 1.2) and is presented in Fig. 2.1.

Figure 2.1 – Block diagram of the technological process

In accordance with this scheme, we will create an algorithm for the model.

This algorithm contains the following blocks:

	– creates transactions at certain time intervals;
	– occupying the queue with a transaction;
	- release of the queue;
	– device occupation;
	– release of the device;
	– delay in processing transactions.

All blocks are written from the first position of the line, first comes the block name, and then, separated by commas, the parameters. There should be no spaces in the parameter entry. If some parameter is missing in the block (set by default), then the comma corresponding to it remains (if it is not the last parameter). If there is a * symbol in the first position of a line, then this line is a comment.

Let's describe the parameters of some blocks:

A). GENERATE A,B,C,D,E,F

Creates transactions at specified time intervals.

A – average time interval between transactions occurrences.

B – 1) if a number, then this is half the field in which the value of the interval between the occurrences of transactions is evenly distributed;

2) if it is a function, then to determine the interval the value of A is multiplied by the value of the function.

C is the moment in time when the first transaction appears.

D – maximum number of transactions.

E – transaction priority value.

F – the number of parameters for the transaction and their type (PB-byte integer, PH-half-word integer, PF-full-word integer, PL-floating point).

b). TERMINATE A

Destroys transactions from the model and decreases the completion counter by A units. The model will terminate if the completion counter becomes less than or equal to zero. If parameter A is missing, then the block simply destroys transactions.

If the device named A is free, then the transaction occupies it (puts it into the “busy” state); if not, then it is queued to it. The device name can be a numeric number or a sequence of 3 to 5 characters.

The transaction releases the device named A, i.e. switches it to the "free" state.

e). ADVANCE A,B

Delays the processing of a transaction by this process and schedules the start time for the next stage of processing.

A - average delay time.

B - has the same meaning as for GENERATE.

Collects statistics about the entry of a transaction into a queue named A.

Collects statistics about the exit of a transaction from the queue named A.

2.2 Development of a program for modeling a technological process using the GPSS language.

Now the task of modeling is to create a machine model on a computer, which will allow us to study the behavior of the system during the simulation time. In other words, you need to implement the constructed block diagram on a computer using blocks and operators of the GPSS language.

Since the operation of the model is associated with the sequential occurrence of events, it is quite natural to use the concept of “Model Time Timer” as one of the elements of the system model. To do this, introduce a special variable and use it to record the current operating time of the model.

When a simulation begins, the simulation timer is usually set to zero. The developer himself decides what value of real time to take as the reference point. For example, the starting point may correspond to 8 a.m. of the first simulated day. The developer must also decide on the choice of the size of the time unit. The time unit can be 1 s, 5 s, 1 min, 20 min, or 1 h. Once a time unit is selected, all time values ​​produced by the simulation or included in the model must be expressed in terms of that unit. In practice, the values ​​of the model time should be quite small compared to the real time intervals occurring in the simulated system. In this system, the time unit usually chosen is 1 minute.

If, when modeling a certain system at the current value of the model time, its state has changed, then you need to increase the timer value. To determine by what amount the timer value should be increased, use one of two methods:

1. The concept of a fixed increment of timer values.

With this approach, the timer value is increased by exactly one unit of time.

Then you need to check the system states and determine those scheduled events that should occur at the new timer value. If there are any, then it is necessary to perform operations that implement the corresponding events, change the timer value again by one unit of time, etc. If the check shows that no events are scheduled for the new timer value, then the timer will move directly to the next value.

2.The concept of variable increment of timer values.

In this case, the condition that causes the timer to increment is the arrival of a "nearby event" time. A near event is an event that is scheduled to occur at a time equal to the next closest value of the model time timer. The fluctuation of the timer increment from case to case explains the expression "variable time increment".

Usually, after a certain point in time, it becomes necessary to stop modeling. For example, it is necessary to prevent new requests from entering the system, but maintenance must continue until the system is released. One way is to introduce a major pseudo-event into the model, called "simulation termination". Then one of the functions of the model will be planning for this event. The point in time, the occurrence of which should cause the simulation to stop, is usually specified as a number. That is, during the simulation, it is necessary to check whether the "simulation end" event is the next event. If "yes", then the timer is set to the time of the end of the simulation, and control is transferred to the procedure that processes the end of the simulation.

The initial data for the development of the program are the time intervals through which the ERE arrive at the first block, the processing time on each block and the simulation time during which it is necessary to study the behavior of the system. The developed program is presented below.

generate 693.34.65

advance 99.6,4.98

advance 450,22.5

advance 248.4,12.42

advance 225,11.25

advance 248.4,12.42

advance 49.8,2.49

The result of the program is presented in Appendix A.

From the results obtained, we see that 6 products will be manufactured in one work shift. At the same time, no queue is created at any of the sites, but at the same time, the technological process of manufacturing the device has not been completed at five sites. The obtained values ​​of the equipment load factor and the processing time at each site when modeling with small deviations correspond to those calculated in the technological part of this graduation project.

Summing up, we conclude that the technological process is designed correctly.

CONCLUSIONS

In the course of the graduation project, the design of a low-frequency amplifier was developed. At the same time, all the requirements of the terms of reference and relevant regulatory documents were taken into account.

In the first section of the graduation project, the initial data were analyzed, the type of production, the stage of development of technological documentation, the type of technological process for organizing production were selected.

A typical technological process was chosen, on the basis of which the PCB assembly TP was formed.

In the second section of the CP, a diagram of the model "hard lead - PCB hole" was calculated and built. A gripping device has been developed.

In the third section, a block diagram and modeling algorithm were developed, on the basis of which the technological process of manufacturing the device was modeled using the GPSS language.

LIST OF LINKS

1 GOST 3.1102-81 “Stages of development and types of documents.”

2 GOST 3.1109-82 “Terms and definitions of basic concepts.”

3 Technology and automation of electronic equipment production: Textbook for universities / Ed. A.P. Dostanko.-M.: Radio and Communications, 2009.

4 Computer production technology – Dostanko A.P. and others: Educational-Mn.: Higher School, 2004.

5 Technological equipment for the development of electronic accounting services: Head. Pos_bnik/M.S.Makurin.-Kharkiv: KhTURE, 1996.

Automation and modeling 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.

Complex automation is characterized by the automatic execution of all functions to carry out the production process without direct human intervention in the operation of the equipment. A person's responsibilities include setting up a machine or group of machines, turning it on and monitoring 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.

With the development of automation, industrial robots (IR) are increasingly 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 use. The characteristic features of PR are automatic control; the ability to quickly and relatively easily reprogram, 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 that operate with minimal human intervention.

One of the main advantages of PR is the ability to quickly changeover 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 changes of production facilities, as well as for the automation of manual low-skilled labor. Equally important is to ensure rapid readjustment of automatic lines, as well as their assembly and commissioning in a short time.

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

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

increasing the quality of products and the volume of their output with a constant number of workers due to reducing the time required to complete operations and ensuring a constant “fatigue-free” mode, increasing the shift ratio of equipment, intensifying existing and stimulating the creation of new high-speed processes and equipment;

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

saving labor and freeing up workers to solve national economic problems.

1.1 Construction and calculation of the “rigid lead – printed circuit board hole” model circuit

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

In the case where a rigid lead is inserted into the board hole, the following characteristic types of contact of the mating elements can be distinguished:

contactless output passage through the hole;

zero type contact when the end of the lead touches the chamfer of the hole;

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

contact of the second type, when the side surface of the lead touches the edge of the hole chamfer;

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

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

The reliable operation of the setting head is significantly influenced by the tolerances of individual elements. In the processes of positioning and movement, a chain of tolerances arises, which in unfavorable cases can lead to an error when installing the ERE, leading to poor-quality assembly.

The assembleability of the product thus depends on three factors:

dimensional and accuracy parameters of the mating surfaces of 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.

Let's consider the case of a zero-type contact, the diagram of which is shown in Figure 1.1.

R F l

Figure 1.1 – Design diagram of a zero-type contact.

Initial data:

F – assembly force directed along the head;

f – friction coefficient;

Rg – reaction of the assembly head, perpendicular to its movement;

N – reaction normal to the chamfer generatrix;

Mg – bending moment relative to the assembly head;

1.2 Design of the gripping device

Gripping devices (GD) of industrial robots are used to grab and hold objects to be manipulated in a certain position. When designing gripping devices, the shape and properties of the object being grabbed, the conditions of the technological process and the features of the technological equipment used are taken into account, which determines the variety of existing gripping devices of the PR. The most important criteria when evaluating the choice of grippers are adaptability to the shape of the object being grasped, grip accuracy and grip strength.

In the classification of gripping devices of the charger, the characteristics that characterize the object of capture, the process of capturing and holding the object, the technological process being served, as well as the signs reflecting the structural and functional characteristics and design basis of the charger are selected as classification ones.

Factors associated with the gripping object include the shape of the object, its mass, mechanical properties, aspect ratio, physical and mechanical properties of the object's materials, and surface condition. The mass of the object determines the required gripping force, i.e. load capacity of the PR, and allows you to select the type of drive and design base of the charger; the state of the surface of the object determines the material of the jaws with which the memory must be equipped; the shape of the object and the ratio of its dimensions also influence the choice of charger design.

The properties of the object's material influence the choice of method for capturing the object, the required degree of sensing of the memory, the possibility of reorienting objects in the process of capturing and transporting them to the technological position. In particular, for an object with a high degree of surface roughness, but non-rigid mechanical properties, it is possible to use only a “soft” clamping element equipped with sensors for determining the clamping force.

The variety of memory devices suitable for solving similar problems, and the large number of features characterizing their various design and technological features, do not allow constructing a classification on a purely hierarchical principle. Gears are distinguished according to the principle of operation: grasping, supporting, holding, capable of relocating an object, centering, basing, fixing.

Based on the type of control, memory devices are divided into: uncontrolled, command, hard-coded, adaptive.

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Automation and modeling 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.

Complex automation is characterized by the automatic execution of all functions to carry out the production process without direct human intervention in the operation of the equipment. A person's responsibilities include setting up a machine or group of machines, turning it on and monitoring 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.

With the development of automation, industrial robots (IR) are increasingly 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 use. The characteristic features of PR are automatic control; the ability to quickly and relatively easily reprogram, 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 that operate 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 changes of production facilities, as well as for the automation of manual low-skilled labor. Equally important is to ensure rapid readjustment of automatic lines, as well as their assembly and commissioning in a short time.

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

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

increasing the quality of products and the volume of their output with a constant number of workers due to reducing the time required to complete operations and ensuring a constant “fatigue-free” mode, increasing the shift ratio of equipment, intensifying existing and stimulating the creation of new high-speed processes and equipment;

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

saving labor and freeing up workers to solve national economic problems.

1.1 Construction and calculation of the “hard lead - printed circuit board hole” model circuit

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

In the case where a rigid lead is inserted into the board hole, the following characteristic types of contact of the mating elements can be distinguished:

contactless output passage through the hole;

zero type contact when the end of the lead touches the chamfer of the hole;

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

contact of the second type, when the side surface of the lead touches the edge of the hole chamfer;

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 criteria for identifying types of contact: change in the normal reaction at the point of contact; friction force; the shape of the elastic line of the rod.

The reliable operation of the setting head is significantly influenced by the tolerances of individual elements. In the processes of positioning and movement, a chain of tolerances arises, which in unfavorable cases can lead to an error when installing the ERE, leading to poor-quality assembly.

The assembleability of the product thus depends on three factors:

dimensional and accuracy parameters of the mating surfaces of 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.

Let's consider the case of a zero-type contact, the diagram of which is shown in Figure 1.1.

MG

RG

R F l

Q

Figure 1.1 - Design diagram of a zero-type contact.

Initial data:

F - assembly force directed along the head;

F = 23 N;

f is the coefficient of friction;

f = 0.12;

l = 8 mm;

= 45;

Q =30.

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

N - reaction normal to the chamfer-forming one;

.

Mg - bending moment relative to the assembly head;

1.2 Design of the gripping device

Gripping devices (GD) of industrial robots are used to grab and hold objects to be manipulated in a certain position. When designing gripping devices, the shape and properties of the object being grabbed, the conditions of the technological process and the features of the technological equipment used are taken into account, which determines the variety of existing gripping devices of the PR. The most important criteria when evaluating the choice of grippers are adaptability to the shape of the object being grasped, grip accuracy and grip strength.

In the classification of gripping devices of the charger, the characteristics that characterize the object of capture, the process of capturing and holding the object, the technological process being served, as well as the signs reflecting the structural and functional characteristics and design basis of the charger are selected as classification ones.

Factors associated with the gripping object include the shape of the object, its mass, mechanical properties, aspect ratio, physical and mechanical properties of the object's materials, and surface condition. The mass of the object determines the required gripping force, i.e. load capacity of the PR, and allows you to select the type of drive and design base of the charger; the state of the surface of the object determines the material of the jaws with which the memory must be equipped; the shape of the object and the ratio of its dimensions also influence the choice of charger design.

The properties of the object's material influence the choice of method for capturing the object, the required degree of sensing of the memory, the possibility of reorienting objects in the process of capturing and transporting them to the technological position. In particular, for an object with a high degree of surface roughness, but non-rigid mechanical properties, it is possible to use only a “soft” clamping element equipped with sensors for determining the clamping force.

The variety of memory devices suitable for solving similar problems, and the large number of features characterizing their various design and technological features, do not allow constructing a classification on a purely hierarchical principle. Gears are distinguished according to the principle of operation: grasping, supporting, holding, capable of relocating an object, centering, basing, fixing.

Based on the type of control, memory devices are divided into: uncontrolled, command, hard-coded, adaptive.

Based on the nature of attachment to the PR hand, all memories are divided into: non-replaceable, replaceable, quick-change, suitable for automatic change.

All grippers are driven by a special device - a drive.

A drive is a system (electrical, electromechanical, electropneumatic, etc.) designed to set in motion the actuators of automated technological and production machines.

Main drive functions: force (power, torque), speed (set of speeds, speed range); the ability to maintain a given speed (force, torque) under conditions of load changes; speed, design complexity; efficiency, cost, dimensions, weight.

Basic requirements for drives. The drive must:

1) comply with all the main characteristics of the given technical specifications;

2) allow electrical remote automatic control;

3) be economical;

4) have a small mass;

5) provide simple coordination with the load.

According to the type of power energy used, drives are distinguished: electric, pneumatic, hydraulic, mechanical, electromechanical, combined.

Pneumatic drives use the energy of compressed air with a pressure of about 0.4 MPa, obtained from the workshop pneumatic network through an air preparation device.

1.2.1 Technical specifications for device design

At the technical specification stage, the optimal structural and layout solution is determined and technical requirements for equipment are drawn up:

1) name and scope - a device for installing ERE on a printed circuit board;

2) the basis for development - the assignment for the CCP;

3) the purpose and purpose of the equipment is to increase the level of mechanization and automation of the technological operation;

4) sources of development - the use of experience in the implementation of technological equipment in the industry;

5) technical requirements:

a) the number of mobility steps is at least 5;

b) maximum load capacity, N 2.2;

c) static force at the operating point of the equipment, N not more than 50;

d) time between failures, hours, not less than 100;

e) absolute positioning error, mm +0.1;

f) speed of movement with maximum load, m/s: - along a free trajectory no more than 1; - along a straight path no more than 0.5;

g) the working space without equipment is spherical with a radius of 0.92;

h) pneumatic drive of the gripping device;

6) safety requirements GOST 12.1.017-88;

7) payback period 1 year.

1.2.2 Description of the design and operating principle of the industrial robot RM-01

The industrial robot (IR) RM-01 is used to perform various operations of folding, installation, sorting, packaging, loading and unloading, arc welding, etc. The general view of the robot is shown in Figure 1.2.

Figure 1.2 - Industrial robot RM-01

The robot manipulator has six stages of mobility. The manipulator links are connected one to another using joints that imitate the human elbow or shoulder joint. Each link of the manipulator is driven by an individual DC electric motor through a gearbox.

The electric motors are equipped with electromagnetic brakes, which allows you to reliably brake the manipulator links when the power is turned off. This ensures the safety of servicing the robot, as well as the ability to move its parts manually. PR RM-01 has a position-contour control system, which is implemented by the SPHERE-36 microprocessor control system, built on a hierarchical principle.

"SPHERE-36" has two levels of control: upper and lower. At the top level the following tasks are solved:

Calculation of algorithms for planning the trajectory of movement of the manipulator gripper and preparation of motion programs for each of its links;

Logical processing of information about the state of the device that makes up the robotic complex, and agreement to work as part of the robotic complex;

Exchange of information with a higher-level computer;

Interactive mode of operation of the operator using a video terminal and keyboard;

Read-write, long-term storage of programs using float drive;

Manual mode of manipulator control using a hand control panel;

Diagnostics of the control system operation;

Calibrating the position of the manipulator links.

At the lower control level, the tasks of processing specified movements by the manipulator links, which are formed at the upper level, are solved. Program positions are worked out at specified parameters (speed, acceleration) using digital electromechanical modules that drive the manipulator links. The control system consists of the following devices: central processing unit (CPM); RAM; ROM; an analog input module (MAV), where signals from potentiometric coarse computational position sensors are supplied; serial interface module (SIM); input/output module (IOM); communication module (MC).

Information exchange between top-level modules is carried out using the system bus.

The lower level of management has:

Drive processor modules (MPM);

Drive control modules (MCM).

The number of MPP and MUP modules corresponds to the number of manipulator links and is equal to 6. The MPP is connected to the communication module using system highways. The electric motors of the manipulator links are controlled using transistor pulse-width converters (PWC), which are part of the power supply unit (PSU). The MCP is based on the K1801 microprocessor and has:

Single-chip processor;

Initial start register;

System RAM, capacity 3216 - bit words; system ROM, with a capacity of 2x16-bit words;

Resident ROM with a capacity of 4x16-bit words;

Programmable timer.

The performance of the MCP is characterized by the following data:

Summation with register addressing means - 2.0 µs;

Summation with mediocre register addressing means - 5.0 µs;

Fixed point multiplication - 65 µs.

The operator panel is designed to perform operations on and off the PR, to select its operating modes.

The main elements of the panel are:

mains power switch (NETWORK);

emergency shutdown button (.EMERGENCY). The mains power turns off when the button is pressed. The button is returned to its initial position by turning it clockwise;

control system power button (CK1);

control system power off button (CK0);

Drive power button (DRIVE 1). At the push of a button
the drive power is turned on, and at the same time the electromagnetic brakes of the motors are unlocked;

Drives power off button (DRIVE 0);

Mode selection switch. It has three positions ROBOT, STOP, RESTART. In ROBOT mode the system works normally. In STOP mode, program execution will stop at the end of the line step.

Moving the switch to ROBOT mode will continue the program execution to the beginning of the next step. RESTART mode is used to restart the execution of a user program from its first step;

Automatic start button (AUTOSTART). Pressing the button starts the system so that the robot begins executing the program without issuing commands from the keyboard. The button is pressed after the SC power is turned on. The mode is activated after turning on DRIVE 1.

The hand control panel is used to position the manipulator during teaching and programming. The remote control provides 5 operating modes:

computer control of the manipulator (COMP);

manual control in the main coordinate system (WORLD);

manual control of degrees of mobility (JOINT);

manual control in the tool coordinate system (TOOL);

Disabling mobility measure drives (FREE).

The selected mode is identified by a signal light.

The speed of movement of the manipulator is adjusted using the “SPEED”, “+”, “-” buttons. To compress and decompress the manipulator’s gripping device, use the “CLOSE” and “OPEN” buttons.

The "STER" button is used to record the coordinates of points when specifying a movement path. The "STOP" button, located at the end of the manual control panel, is intended to interrupt the execution of the program by turning off the power to the drives. Used to stop movement in normal situations. The "OFF" button has the same purpose as the "STOP" button. The difference is that the power to the manipulator drives is not turned off.

Moving the joints of the manipulator using the hand control panel is carried out in three modes: JOINT, WORLD and TOOL.

In the JOINT mode (selected by the corresponding button on the control panel), the user can directly control the movement of individual links of the manipulator. This movement corresponds to pairs of buttons “-” and “+”, respectively, for each link of the manipulator (i.e. column, shoulder, elbow, and three grip movements).

In WORLD mode, the system is actually fixed relative to the main coordinate system and moved in certain directions of this system (X, Y, Z, respectively).

It should be noted that work in the WORLD mode can be carried out at low speeds to avoid getting into the boundary of the robot's arm space. We also point out that the movement is provided automatically with the help of all links of the manipulator simultaneously.

TOOL mode provides movement in the active coordinate system.

A 12-bit line indicator is designed to display information about operating modes and errors:

NOKIA AOX - appears briefly upon startup;

ARM PWR OFF - power supply to the manipulator drives is turned off;

MANUAL MODE - allowed to control the robot from the control panel;

COMP MODE - the manipulator is computer-controlled;

LIMIT STOR - the joint is moved to the extreme position;

TOO CLOSE - the given point is very close to the manipulator;

FAR LLP - the specified point is outside the robot’s working area;

TEACH MOOE - the TEACH mode is activated, the manipulator follows arbitrary trajectories;

STEACH MODE - the STEACH-S mode is activated, the manipulator moves after straight-line trajectories;

ERROR - the buttons on the hand control are pressed at the same time, which constitute an illegal operation, etc..

In addition, the indicator of the selected speed with this encoding:

1 illuminated element - tool speed? 1.9 mm/s;

2 illuminated element - tool speed? 3.8 mm/s;

3 illuminated element - tool speed? 7.5 mm/s;

4 illuminated element - tool speed? 15.0 mm/s;

5 illuminated element - tool speed? 30 mm/s;

6 illuminated element - tool speed? 60 mm/s;

7 illuminated element - tool speed? 120 mm/s;

8 illuminated element - tool speed? 240 mm/s.

Below is an example of the control program PR RM-01 for drilling holes for surface mounting ERE:

G04 File: SVETOR~1.BOT, Thu Dec 01 21:35:19 2006*

G04 Source: P-CAD 2000 PCB, Version 10.15.17, (C:\DOCUME~1\Shepherd\WORKERS~1\SVETOR~1.PCB)*

G04 Format: Gerber Format (RS-274-D), ASCII*

G04 Format Options: Absolute Positioning*

G04 Leading-Zero Suppression*

G04 Scale Factor 1:1*

G04 NO Circular Interpolation*

G04 Millimeter Units*

G04 Numeric Format: 4.4 (XXXX.XXXX)*

G04 G54 NOT Used for Aperture Change*

G04 File Options: Offset = (0.000mm,0.000mm)*

G04 Drill Symbol Size = 2.032mm*

G04 Pad/Via Holes*

G04 File Contents: Pads*

G04 No Designators*

G04 No Drill Symbols*

G04 Aperture Descriptions*

G04 D010 EL X0.254mm Y0.254mm H0.000mm 0.0deg (0.000mm,0.000mm) DR*

G04 "Ellipse X10.0mil Y10.0mil H0.0mil 0.0deg (0.0mil,0.0mil) Draw"*

G04 D011 EL X0.050mm Y0.050mm H0.000mm 0.0deg (0.000mm,0.000mm) DR*

G04 "Ellipse X2.0mil Y2.0mil H0.0mil 0.0deg (0.0mil,0.0mil) Draw"*

G04 D012 EL X0.100mm Y0.100mm H0.000mm 0.0deg (0.000mm,0.000mm) DR*

G04 "Ellipse X3.9mil Y3.9mil H0.0mil 0.0deg (0.0mil,0.0mil) Draw"*

G04 D013 EL X1.524mm Y1.524mm H0.000mm 0.0deg (0.000mm,0.000mm) FL*

G04 "Ellipse X60.0mil Y60.0mil H0.0mil 0.0deg (0.0mil,0.0mil) Flash"*

G04 D014 EL X1.905mm Y1.905mm H0.000mm 0.0deg (0.000mm,0.000mm) FL*

G04 "Ellipse X75.0mil Y75.0mil H0.0mil 0.0deg (0.0mil,0.0mil) Flash"*

G04 D015 SQ X1.524mm Y1.524mm H0.000mm 0.0deg (0.000mm,0.000mm) FL*

G04 "Rectangle X60.0mil Y60.0mil H0.0mil 0.0deg (0.0mil,0.0mil) Flash"*

G04 D016 SQ X1.905mm Y1.905mm H0.000mm 0.0deg (0.000mm,0.000mm) FL*

G04 "Rectangle X75.0mil Y75.0mil H0.0mil 0.0deg (0.0mil,0.0mil) Flash"*

After drilling holes in the PCB, the robot installs the ERE. After installing the ERE, the board is sent for wave soldering.

2 MODELING OF THE TECHNOLOGICAL PROCESS

Modeling is a method for studying complex systems, based on the fact that the system under consideration is replaced by a model and the model is studied in order to obtain information about the system being studied. A model of the system under study is understood as some other system that behaves, from the point of view of the objectives of the study, similar to the behavior of the system. Usually, a model is simpler and more accessible for research than a system, which makes it easier to study it. Among the various types of modeling used to study complex systems, simulation modeling plays a large role.

Simulation modeling is a powerful engineering method for studying complex systems, used in cases where other methods are ineffective. A simulation model is a system that displays the structure and functioning of the original object in the form of an algorithm that connects input and output variables accepted as characteristics of the object under study. Simulation models are implemented in software using various languages. One of the most common languages ​​specifically designed for building simulation models is GPSS.

The GPSS (General Purpose System Simulator) system is designed for writing simulation models of systems with discrete events. The GPSS system most conveniently describes models of queuing systems, which are characterized by relatively simple rules for the functioning of their constituent elements.

In GPSS, the system being modeled is represented by a set of abstract elements called objects. Each object belongs to one of the object types.

Each object type is characterized by a specific behavior and set of attributes defined by the object type. For example, if we consider the work of a port, loading and unloading arriving ships, and the work of a cashier in a movie theater, issuing tickets to patrons, we will notice great similarities in their functioning. In both cases, there are objects that are constantly present in the system (the port and the cashier) that process objects entering the system (ships and movie theater patrons). In queuing theory, these objects are called devices and requests. When processing of an incoming object ends, it leaves the system. If at the time of receipt of the request the service device is busy, then the request is placed in a queue, where it waits until the service device becomes free. A queue can also be thought of as an object whose function is to store other objects.

Each object can be characterized by a number of attributes that reflect its properties. For example, a service device has a certain productivity, expressed by the number of requests it processes per unit time. The application itself can have attributes that take into account the time it spent in the system, the time it waited in the queue, etc. A characteristic attribute of a queue is its current length, by observing which during operation of the system (or its simulation model), one can determine its average length during operation (or simulation). The GPSS language defines object classes with which you can define service devices, customer flows, queues, etc., as well as set specific attribute values ​​for them.

Dynamic objects, called transactions in GPSS, are used to specify service requests. Transactions can be generated during the simulation and destroyed (leave the system). The creation and destruction of transactions is performed by special objects (blocks) GENERATE and TERMINATE.

Messages (transactions) are dynamic GPSS/PC objects. They are created at certain points in the model, promoted by the interpreter through the blocks, and then destroyed. Messages are analogous to thread units in a real system. Messages can represent different elements even within the same system.

Messages move from block to block in the same way as the elements they represent (programs in the computer example) move.

Each promotion is considered an event that must occur at a specific point in time. The GPSS/PC interpreter automatically determines when events occur. In cases where an event cannot occur, although the time for its occurrence has approached (for example, when trying to occupy a device when it is already occupied), the message stops moving until the blocking condition is removed.

Once the system has been described in terms of the operations it performs, it must be described in GPSS/PC language using blocks that perform the corresponding operations in the model.

The user can define special points in the model at which statistics about queues need to be collected. Then the GPSS/PC interpreter will automatically collect statistics about queues (queue length, average time spent in queue, etc.). The number of delayed messages and the duration of these delays are determined only at these given points. The interpreter also automatically counts the total number of messages arriving at the queue at these points. This is done in much the same way as for devices and memories. Certain counters count the number of messages delayed in each queue, since the number of messages that pass any point in the model without delay may be of interest. The interpreter calculates the average time a message spends in the queue (for each queue), as well as the maximum number of messages in the queue.

2.1 Development of a block diagram and modeling algorithm

To model queuing systems, a general-purpose modeling system, GPSS, is used. This is necessary due to the fact that in the practice of research and design of complex systems, there are often systems that need to process a large flow of requests passing through servicing devices.

Models based on GPSS consist of a small number of operators, due to which they become compact and, accordingly, widespread. This is because GPSS has built-in the maximum possible number of logic programs required for modeling systems. It also includes special tools for describing the dynamic behavior of time-varying systems, with changes in state occurring at discrete moments in time. GPSS is very easy to program because the GPSS interpreter performs many functions automatically. Many other useful elements are included in the language. For example, GPSS maintains a simulation time timer, schedules events to occur later in the simulation time, causes them to occur on time, and manages the order of arrival.

To develop a block diagram, we will analyze the technological process of assembling the module being developed.

This technological process is characterized by sequential execution of technological operations. Therefore, the block diagram will look like a chain of sequentially connected blocks, each of which corresponds to its own technological operation and each of which lasts a certain time. The connecting links of these blocks are the queues formed as a result of each technological operation, and are explained by the different execution times of each of them. This block diagram is based on the design diagram for the assembly process of the designed module (Fig. 1.2) and is presented in Fig. 2.1.

Figure 2.1 - Block diagram of the technological process

In accordance with this scheme, we will create an algorithm for the model.

This algorithm contains the following blocks:

All blocks are written from the first position of the line, first comes the block name, and then, separated by commas, the parameters. There should be no spaces in the parameter entry. If some parameter is missing in the block (set by default), then the comma corresponding to it remains (if it is not the last parameter). If there is a * symbol in the first position of a line, then this line is a comment.

Let's describe the parameters of some blocks:

A). GENERATE A,B,C,D,E,F

Creates transactions at specified time intervals.

A is the average time interval between the occurrences of transactions.

B - 1) if a number, then this is half of the field in which the value of the interval between the occurrences of transactions is evenly distributed;

2) if it is a function, then to determine the interval the value of A is multiplied by the value of the function.

C is the moment in time when the first transaction appears.

D - maximum number of transactions.

E - transaction priority value.

F - the number of parameters of the transaction and their type (PB-byte integer, PH-half-word integer, PF-full-word integer, PL-floating point).

b). TERMINATE A

Destroys transactions from the model and decreases the completion counter by A units. The model will terminate if the completion counter becomes less than or equal to zero. If parameter A is missing, then the block simply destroys transactions.

If the device named A is free, then the transaction occupies it (puts it into the “busy” state); if not, then it is queued to it. The device name can be a numeric number or a sequence of 3 to 5 characters.

The transaction releases the device named A, i.e. switches it to the "free" state.

e). ADVANCE A,B

Delays the processing of a transaction by this process and schedules the start time for the next stage of processing.

A - average delay time.

B - has the same meaning as for GENERATE.

Collects statistics about the entry of a transaction into a queue named A.

Collects statistics about the exit of a transaction from the queue named A.

2 .2 Development of a program for modeling the technological process using the GPSS language.

Now the task of modeling is to create a machine model on a computer, which will allow us to study the behavior of the system during the simulation time. In other words, you need to implement the constructed block diagram on a computer using blocks and operators of the GPSS language.

Since the operation of the model is associated with the sequential occurrence of events, it is quite natural to use the concept of “Model Time Timer” as one of the elements of the system model. To do this, introduce a special variable and use it to record the current operating time of the model.

When a simulation begins, the simulation timer is usually set to zero. The developer himself decides what value of real time to take as the reference point. For example, the starting point may correspond to 8 a.m. of the first simulated day. The developer must also decide on the choice of the size of the time unit. The time unit can be 1 s, 5 s, 1 min, 20 min, or 1 h. Once a time unit is selected, all time values ​​produced by the simulation or included in the model must be expressed in terms of that unit. In practice, the values ​​of the model time should be quite small compared to the real time intervals occurring in the simulated system. In this system, the time unit usually chosen is 1 minute.

If, when modeling a certain system at the current value of the model time, its state has changed, then you need to increase the timer value. To determine by what amount the timer value should be increased, use one of two methods:

1. The concept of a fixed increment of timer values.

With this approach, the timer value is increased by exactly one unit of time.

Then you need to check the system states and determine those scheduled events that should occur at the new timer value. If there are any, then it is necessary to perform operations that implement the corresponding events, change the timer value again by one unit of time, etc. If the check shows that no events are scheduled for the new timer value, then the timer will move directly to the next value.

2.The concept of variable increment of timer values.

In this case, the condition that causes the timer to increment is the "close event" time. A close event is an event that is scheduled to occur at a point in time equal to the next closest model timer value. The fluctuation of the timer increment from case to case explains the expression "variable time increment".

Usually, after a certain point in time, it becomes necessary to stop modeling. For example, it is necessary to prevent new requests from entering the system, but maintenance must continue until the system is released. One way is to introduce a major pseudo-event into the model, called "simulation termination". Then one of the functions of the model will be planning for this event. The point in time, the occurrence of which should cause the simulation to stop, is usually specified as a number. That is, during the simulation, it is necessary to check whether the "simulation end" event is the next event. If "yes", then the timer is set to the time of the end of the simulation, and control is transferred to the procedure that processes the end of the simulation.

The initial data for the development of the program are the time intervals through which the ERE arrive at the first block, the processing time on each block and the simulation time during which it is necessary to study the behavior of the system. The developed program is presented below.

generate 693.34.65

advance 99.6,4.98

advance 450,22.5

advance 248.4,12.42

advance 225,11.25

advance 248.4,12.42

advance 49.8,2.49

The result of the program is presented in Appendix A.

From the results obtained, we see that 6 products will be manufactured in one work shift. At the same time, no queue is created at any of the sites, but at the same time, the technological process of manufacturing the device has not been completed at five sites. The obtained values ​​of the equipment load factor and the processing time at each site when modeling with small deviations correspond to those calculated in the technological part of this graduation project.

Summing up, we conclude that the technological process is designed correctly.

CONCLUSIONS

In the course of the graduation project, the design of a low-frequency amplifier was developed. At the same time, all the requirements of the terms of reference and relevant regulatory documents were taken into account.

In the first section of the graduation project, the initial data were analyzed, the type of production, the stage of development of technological documentation, the type of technological process for organizing production were selected.

A typical technological process was chosen, on the basis of which the PCB assembly TP was formed.

In the second section of the CP, a diagram of the "hard terminal - PCB hole" model was calculated and built. A gripping device has been developed.

In the third section, a block diagram and modeling algorithm were developed, on the basis of which the technological process of manufacturing the device was modeled using the GPSS language.

LIST OF LINKS

1 GOST 3.1102-81 “Stages of development and types of documents.”

2 GOST 3.1109-82 “Terms and definitions of basic concepts.”

3 Technology and automation of electronic equipment production: Textbook for universities / Ed. A.P. Dostanko.-M.: Radio and Communications, 2009.

4 Computer production technology - Dostanko A.P. and others: Educational-Mn.: Higher School, 2004.

5 Technological equipment for the development of electronic accounting services: Head. Pos_bnik/M.S.Makurin.-Kharkiv: KhTURE, 1996.

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Automation and modeling 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.

Complex automation is characterized by the automatic execution of all functions to carry out the production process without direct human intervention in the operation of the equipment. A person's responsibilities include setting up a machine or group of machines, turning it on and monitoring 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.

With the development of automation, industrial robots (IR) are increasingly 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 use. The characteristic features of PR are automatic control; the ability to quickly and relatively easily reprogram, 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 that operate with minimal human intervention.

One of the main advantages of PR is the ability to quickly changeover 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 changes of production facilities, as well as for the automation of manual low-skilled labor. Equally important is to ensure rapid readjustment of automatic lines, as well as their assembly and commissioning in a short time.

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

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

increasing the quality of products and the volume of their output with a constant number of workers due to reducing the time required to complete operations and ensuring a constant “fatigue-free” mode, increasing the shift ratio of equipment, intensifying existing and stimulating the creation of new high-speed processes and equipment;

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

saving labor and freeing up workers to solve national economic problems.

1.1 Construction and calculation of the “rigid lead – printed circuit board hole” model circuit

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

In the case where a rigid lead is inserted into the board hole, the following characteristic types of contact of the mating elements can be distinguished:

contactless output passage through the hole;

zero type contact when the end of the lead touches the chamfer of the hole;

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

contact of the second type, when the side surface of the lead touches the edge of the hole chamfer;

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

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

The reliable operation of the setting head is significantly influenced by the tolerances of individual elements. In the processes of positioning and movement, a chain of tolerances arises, which in unfavorable cases can lead to an error when installing the ERE, leading to poor-quality assembly.

The assembleability of the product thus depends on three factors:

dimensional and accuracy parameters of the mating surfaces of 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.

Let's consider the case of a zero-type contact, the diagram of which is shown in Figure 1.1.

M G

R G

N

R F l

Q



Figure 1.1 – Design diagram of a zero-type contact.

Initial data:

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