What materials are used in the production of ceramics. Ceramic materials in construction. Stages of preparing clay for work

MODERN CAD TP AND THEIR IMPROVEMENT

Modern machine-building production is experiencing an ever-increasing need for high-grade, highly efficient CAD TP for various purposes.

Until the early 90s. XX century in domestic mechanical engineering, with rare exceptions, CAD TP of domestic development was used. Many enterprises, and above all the military-industrial complex, created, operated and replicated their own systems. Along with efficiently operating CAD TP, there were a significant number of systems that did not meet the requirements for such systems, which had very limited areas of application, low reliability, etc. The need to work with such systems often caused a negative attitude among design engineers towards the very idea of automation of TP design.

At the end of the XX century. Enterprise CAD policy has changed dramatically. Enterprises stopped developing their own systems and started buying licensed CAD TPs of the required configuration and functionality. The number of domestic developers of CAD TP has dropped sharply. Foreign systems began to enter the market. However, if the adaptation of CAD to foreign development to domestic conditions of use and its "Russification" are relatively simple, then similar actions with CAD TP often cause serious difficulties. First of all, there are differences in the regulatory frameworks (domestic standards do not coincide with foreign ones). The brands of the materials used do not coincide, the methods for determining their characteristics differ. The general methodology for designing TP, approaches to determining the processing modes, assessing possible cutting forces, etc. do not coincide. All this imposes serious restrictions on the competitiveness of CAD TP of foreign design in the domestic market.

The market "niche" of foreign-made CAD systems in the domestic market can be considered CAD K and CAD. The creation of CAD routing and operational technologies for use in domestic enterprises should be considered the prerogative of domestic developers. Some domestic enterprises have already begun to use "bundles" of CAD of foreign and domestic development: automated design of a product and its elements is performed using foreign CAD, and technological preparation - using domestic CAD TP. When integrating systems, the problems of compatibility of the formats of exported (imported) data become of the highest priority.

Consider the implementation of some domestic CAD TP , found application in industry.

KOMPAS-Avtoproekt... The developer is ASKON. The KOMPAS-Avtoproekt complex is intended for use in integrated systems for automated support of life cycle services based on CALS technologies, as a means of automation of the CCI.

Starting from version 9.3, KOMPAS-Avtoproekt is an automation server that provides client applications for using over 300 different methods and service programs.

External applications working with KOMPAS-Avtoproekt can:

React to events occurring on the server: opening and closing databases, changing subsystems, tables, changing data, terminating an application, etc.;

Receive data about the current state of the system: the contents of the active table, the last executed SQL query, configuration settings, username, rank, etc .;

Manage the system: load the required databases, automatically navigate through tables, copy information from directories, select blocks of records, delete or insert them, etc.

The open architecture of the system allows enterprises to independently develop new software modules and integrate them into the software package. Using the capabilities of the KOMPAS-Avtoproekt automation server facilitates the development of applications, practically removes the restrictions on adapting the system to the special requirements of customers and provides a solution to various tasks of the Chamber of Commerce and Industry, including the possibility of integrating with the ERP / MRP / PLM systems already operating at the enterprise.

The main technical means of the workstation of the system is a personal computer of standard configuration with the Windows operating system.

The implemented technological modules provide:

Calculation of material consumption rates;

Calculation of cutting conditions;

Definition of welding modes;

Rationing of labor costs;

Registration of technological documentation for the developed TP;

Search for TP in the archive.

In the automated calculation of material consumption rates, the standards of technological losses, waste due to the fact that the dimensions of the initial material are not multiple are taken into account, etc. Depending on the type and profile of the workpiece, various calculation methods are provided, for example, the calculation of the consumption rates of sheet material for individual cutting, etc. It is possible to customize the system to the algorithms for the rationing of the material operating at the enterprise. For optimal cutting of sheet material, the CAD Intech-Cutting W / L included in the software package is provided.

The subsystem for calculating cutting conditions for machining methods allows you to determine the main and auxiliary times of the corresponding technological transition. The type and geometry of the processed structural element, the physical and mechanical properties of the material and the state of the surface layer of the workpiece, the rigidity of the technological system, the passport data of the machine, the parameters of the cutting tool, etc. are taken into account. The auxiliary time for the main transition is determined according to general machine-building standards. It is possible to set up for various calculation algorithms, including using the methods adopted at the enterprise.

When determining the modes for various welding methods, the required welding materials (electrodes, welding wire, shielding gases) and their consumption rates are selected. Consider the structural elements of welds according to current standards, the position of the seam in space and the equipment used.

The regulation of operations according to the enlarged standard norms is stipulated, as well as the regulation of individual technological transitions. Rationing according to the enlarged standard standards is used in single and small-scale production. Detailed rationing for each transition - in large-scale and mass. When standardizing, take into account the time for installing the workpiece, for control measurements, as well as the necessary preparatory and final time. When determining the piece-costing time, the type of production, as well as all the main components of the piece time, are taken into account.

Registration of various technological documents is possible:

Sheets for timely provision of production with materials, tooling or calculating the cost of making an order;

Maps (for example, operating rooms).

The program for processing technological documents uses a special step-by-step environment for typing and setting their parameters. It is possible to generate documents in the MS Exce1 environment, insert them into maps of sketches from CAD systems, add any text documents to maps, including those prepared in Microsoft Word.

The search for TP in the archive is performed according to the content of technological operations and transitions. The user can search for TP by the equipment used, cutting tools, measuring instruments, etc. The technological solutions implemented in the found TP can be used in the future as analogous solutions.

KOMPAS-Avtoproekt is completed on a modular basis. This makes it possible to organize work places for technologists for various types of production, as well as work places for specialists in ordering, material and labor rationing. When creating a unified complex for automation of design and technological preparation at the enterprise, the storage of information created in KOMPAS-Avtoproekt is performed by the control system of the ZHCI LOTSMAN: PLM (or another PDM / PLM system).

KOMPAS-Avtoproekt can interact with the system of three-dimensional solid modeling KOMPAS 3D, which performs the function of CAD K, moreover, it is supplemented by a system of strength analysis. The latter is used to make an informed choice of the material of a part from a built-in directory containing information on more than 500 metallic and the same number of non-metallic materials.

Complex KOMPAS-Avtoproekt 9.4 client-server version consists of two subsystems KOMPAS-Avtoproekt-Technology and KOMPAS-Avtoproekt-Specifications.

The KOMPAS-Avtoproekt-Technology subsystem provides:

Computer-aided design of TP of the main types of production;

Automatic formation of a standard set of technological documentation and documents of any form in MS Excel format;

Operational viewing of graphics: drawings of parts, tools, operational sketches, setup maps, etc.;

Integration with LOTSMAN systems: PLM, PartY Plus, Team-Center, Baan;

Calculation of cutting conditions;

Labor rationing of technological operations;

The ability to customize samples of technological documents;

Translation of technologies into foreign languages;

Possibility of user development of technology design subsystems for various types of industries;

Automated generation of part code according to
with ESKD and TKD;

Execution of settlement procedures.

Computer-aided design of TP is performed in the following modes:

Based on a TP-analogue with automatic selection of the appropriate technology from the archive according to various criteria, including the design and technological code of the part;

Using a typical TP;

Using a library of typical technological operations and transitions;

Automatic revision of a typical technology based on data transferred from a parametrized drawing or a KOMPAS sketch;

Automatic completion of a typical technology based on calculated data or a table of standard sizes of manufactured parts.

KOMPAS products are successfully integrated with foreign CAD systems. When automating the design of products and their elements, some enterprises use the "bundle" Unigraphics-KOM-PAS 3D. When automating the CCI, the KOMPAS-Avtoproekt-Cimatron "bundle" is used (preparation of control programs for CNC equipment).

T-FLEX (integrated software package). Developer - Top Systems company includes:

CAD K (CAD-system) T-FLEX CAD;

SAP (CAM-system) T-FLEX CNC;

the automation system for engineering calculations (САЕ-system) T-FLEX / Euler;

CAD TP (CAPR system) T-FLEX / TechnoPro;

PDM system T-FLEX DOCs.

The complex is designed to be used as the basis (kernel) of an integrated system for automated support and management of the life cycle complex and is implemented on personal computers of standard configurations with the Windows operating system.

Each component of the complex can be used autonomously and have a modern interface. The set of functions performed includes all the standard operations performed by mid-range systems.

One of the main ideas inherent in the T-Flex software products is the idea of parameterization - the desire to obtain a specific design object, for example, a model of a specific part, by appropriately changing (or setting) the required parameter values of the existing parameterized object model.

CAD component K is represented by a medium-level plane (T-FLEX CAD 2D) and three-dimensional (T-FLEX CAD 3D) modeling system. The plane modeling system allows you to create parametric models of parts of unlimited complexity. 3D solid modeling is based on the use of the Parasolid kernel from EDS.

After creating a drawing or a three-dimensional model in T-FLEX SAE, data on its geometry, dimensions and technical conditions could be transferred in a semi-automatic or automatic mode to the T-FLEX / TechnoPro system, where a set of documents will be received in accordance with the ESTD.

The developers of the complex believe that parametric changes in the original design models of parts will lead to the necessary automatic changes in the technological documentation. A similar situation can be traced for the example of the T-FLEX CAD-T-FLEX CNC link: thanks to the full integration of these systems, all parametric designer tools become available to the technologist. When you change the drawing or three-dimensional model, the control program changes, which can be saved in the PDM system by a separate command.

In CAD TP T-FLEX / TechnoPro, parametric technological design is used. The system database stores parametric TPs corresponding to parametric models of products in the integrated CAD system K. The design process is reduced to adapting the parametric TP model, which plays the role of TP-analog, to the design and technological characteristics of a specific part, adjusting the resulting single TP and editing it. The last steps are mandatory, since quantitative changes in the parameters of the part model can lead to qualitative changes in technological solutions. For the designed process, a new set of technological documents is formed, which is saved in the PDM system database in the form of T-FLEX DOCs objects.

The systems for preparing programs for CNC machines included in the T-FLEX complex - the T-FLEX CNC 20 and T-FLEX CNC 30 systems - allow you to create control programs for almost all types of processing that exist today: EDM, laser, turning, drilling, milling (2 - 5-axis) and engraving. Architecturally, these systems are built into the T-FLEX CAD design system, i.e. have a common modeling interface and a common parametric kernel. This allows you to create NC programs associated with the design geometry of 2D and 3D models. When the geometry of the parts changes according to certain parameters, an automated change in the control programs for their processing occurs.

Using associatively linked models of parts and NC programs, specialists can apply standard solutions at enterprises by borrowing projects from the T-FLEX DOCs knowledge base, followed by changing parameters in T-FLEX CAD and obtaining control programs in T-FLEX CNC.

The created control programs are saved in T-FLEX DOCs, where a number of modules included in the CAM-systems block of the T-FLEX-T-FLEX NC Tracer complex can be used to view them (simulate processing taking into account material removal). Simulation is carried out for milling (2 -5-axis), turning and drilling operations.

The cycle of preparation and testing of the control program includes:

Modeling of the manufactured part - CAD / CAM-system, construction of a trajectory using linear approximation;

Transformation - recalculation of the trajectory coordinates, taking into account the tool overhang, the dimensions of the equipment;

Postprocessor - recalculation of the trajectory coordinates, taking into account the kinematics of the machine;

Rack CNC - coordinate interpolation in the control program.

The use of a unified software for the CCI and control of CNC machines allows minimizing the errors of mathematical transformations that accumulate in the control program. The postprocessor library is focused on a wide range of CNC systems used in industry.

The T-FLEX / Technology system, as conceived by the developers, allows for the parallel work of the design and technological departments of the enterprise. The designer creates drawings of the product in T-FLEX CAD, then these drawings go to the technologist, who connects the design parameters with the initial data for the formation of technological operations, introduces the missing technological information (information about the structural elements). Thus, the system reads the initial data from the design drawing and then uses it to calculate the parameters of the TP for manufacturing the product. Any changes to dimensions, tolerances, roughness or other designations in the drawing will lead to recalculation of the transition parameters. Sharing these systems also avoids double entry of information and avoids human error.

The local and collective (working in the T-FLEX DOCs environment) versions of the system have been developed, with the use of a powerful industrial DBMS MS SQL Server.

The system was created as a tool that does not replace the technologist, but significantly accelerates and simplifies the design of technology, the calculation of processing modes, norms and technological dimensional chains, the formation of transition texts, the selection of the necessary technological equipment, the formation of documentation and operational sketches.

T-FLEX / Technology provides automated development of route, route-operational and operational technologies, including the following operations: blank, mechanical and heat treatment, coating, locksmith, assembly, etc. Dialogue mode provides the formation of TP by selecting the necessary operations, transitions and tooling from the reference books of the system, and the TPs created in this way can serve as a basis for their use in the future as TP analogs. Using the dialogue tools of the system, you can add or change operations, transitions, their sequence and technological equipment in them.

The choice of technological equipment is made from the information base of the system. It contains data on the names of operations, equipment, fixtures, auxiliary materials, cutting, measuring and auxiliary tools, blanks, components for assembly TP, etc. Parameters, classification signs and illustrations can be added to each type of technological equipment in the information base. Accelerated selection of equipment allows you to manage each subsequent stage of selection, depending on the choice at the previous stage.

The design tools are supplemented with databases containing calculations of processing modes, labor intensity, interoperational dimensions and material consumption. Databases are open for changing and adding methods, calculation algorithms and tabular data.

Technologi CS... The developer is Consistent Software. The complex, combining the Mechani CS and Technologi CS software products, can be considered as an integrated CAD system that forms a unified system for technical preparation of production and a common base of design and technological information.

Mechani CS system provides:

Formation of drawings and specifications for ESKD, design information in a unified CCI system;

Automation of standards control.
Technologi CS system provides:

Computer-aided design of TP;

Material and labor rationing;

Performing automated calculations for a unit, product, production program:

Determination of the need for materials, standard products, components, tools, etc .;

Determination of the consolidated labor intensity;

Equipment load assessment;

Calculation of the duration of the production cycle.

Each of the systems can be used autonomously and implemented on the basis of personal computers of standard configuration in the Windows operating system.

The Technologi CS system, along with the automation of the TP design, allows the formation of the necessary information for planning, dispatching and production management.

The design of TP in the system is carried out on the basis of analogous processes. The developers of the system, when creating it, proceeded from the following basic principles:

The technologist should not repeatedly describe the TP (that is, having once developed a typical or group TP, he should use it when working with a single TP);

Documentation (including lists of parts, including a list of operations for a typical TP and their individual characteristics) should be generated automatically;

The system must store in a single TP the connections of operations performed according to a standard (group TP) with an analogue process in order to provide the necessary changes in it;

A technologist, working with an end-to-end unit TP, must have information about which operations of this TP belong to various typical and group processes.

A separate reference book is intended for the development and storage of analogous processes in the system.

An analogue process (for example, a typical TP) contains an exhaustive list of technological operations typical for all parts manufactured on its basis. For each operation, equipment, transitions, tools, auxiliary materials and modes that are common for the entire set of parts manufactured according to this TP can be indicated.

The transfer of information about a typical TP during the design on its basis of single TP is carried out using parameters of two types:

Technological redistribution (type of processing);

The unique number of the operation in a typical TP.

The parameter "Technological redistribution" is of a reference type: it refers to a specially created reference book of redistributions. Each element of a typical (group) TP should have such a parameter, since it is this parameter that serves as the very feature that distinguishes the elements of a typical TP from the rest in single TP. Each technological conversion has its own type of documentation set.

The "Unique operation number in a typical TP" parameter is required to automatically generate a list of operations for parts in sheets (used for group TP): it is connected only to TP operations.

Parts processed according to a standard TP are grouped in the form of a specification for the corresponding item of the nomenclature (in this case, for an element of the TP reference book). To create a BOM, the technologist is provided with tools for searching, grouping and sorting parts according to various criteria, for example, by the type of coverage.

The structure of a single TP is determined by the technologist. Using typical TP, he places fragments of an analogue process or even an entire process, for example, the process of electroplating, in the necessary (in his opinion) places. The inclusion of fragments of a typical TP into a single one is carried out by the method of copying and pasting: Select All / Copy / Paste. After the completion of the design of a single TP, the necessary technological documentation is generated automatically.

Information about individual TPs is stored in the corresponding database and can be used to form production plans and to record their implementation step by step.

TechnoPro(a complex of technological design and preparation of production). The developer is the Vector-Alliance corporation.

The complex is focused on using the CALS-based automated support system as a technological core.

The complex will be delivered in three versions:

TechnoPro Basic - basic version for working at local workplaces or in networks for several users;

TechnoPro Standard - client-server standard version for working in large networks with hundreds of users and a single SQL database;

TechnoPro Basic - client-server version with maximum capabilities, contains unique automated design tools and is designed to work in large networks with hundreds of users and a single SQL database.

Here, a SQL database is understood as a database with an industrial DBMS MS SQL Server for storing large amounts of information.

Being the minimum component of the complex, the TechnoPro Basic system contains all the tools necessary for the design of the TP.

TechnoPro Basic provides support for the design of operating technology, including blanking operations, mechanical and heat treatment operations, coating, locksmith operations, technical control operations, assembly, stamping, welding, etc. The system generates operating, route-operating and route flow charts, tooling lists , control cards, materials and components, title pages and other technological documents.

The user himself defines the structure of a single route TP, using dialog editing or TP-analog. Design and technological parametrization is widely used. Parametric TP, called by the developers of the complex general technological processes (OTP), contain a description of the technology for manufacturing groups, parts without specifying specific sizes or designs.

When used at an enterprise, standard or group TP TechnoPro Basic provides the possibility of their parameterization. Such parametric TP can be automatically recalculated, and the information for recalculation (design description) can be obtained from design CAD systems or manually from a drawing made on paper.

The information support of the TechnoPro complex includes five interconnected databases: products and specifications, specific (single) TP (KTP), OTP, information base (IB), base of conditions and calculations (BUR).

General technological processes are used for parametric design, as an initial TP-analog, single, typical and group TP. In the case of designing group TP, it is enough to enter into the system a list of parts for which TP will be generated, and options for dimensions or other parameters from the table of the group drawing.

In the generated TP and in the operational maps, the TechnoPro system automatically creates tables indicating the list of parts and the corresponding values of technological (performed) and drawing dimensions or other parameters of the processed elements. Group TP can be designed in the TechnoPro system for any type of production: casting, stamping, machining, electroplating, painting, heat treatment, etc. After the TP is formed, the user views and edits it in a dialogue mode.

Integration of TechnoPro with CAD K creates the basis for the simultaneous (parallel) execution of design and technological design. The complex has interfaces with T-FLEX CAD, SolidWorks, Pro / ENGINEER, Unigraphics, etc.

To use the complex in integrated systems for automated support of the life cycle, various options for its interaction with PDM and ERP systems are provided. When forming such a system, to expand the capabilities of PDM or ERP in terms of managing technological data, the following subsystems have been developed:

TechnoPro / Production - collection of any summary data on the designed TP and the formation of documents in MS Excel;

TechnoPro / Simas - formation of material specifications for calculating the requirements for blanks and components;

TechnoPro / Materials - reference book (database) on materials, assortments and components;

TechnoPro / Planning - planning of works and resources.

TechnoCad interface implements data reading for technological design from electronic models and drawings made in CAD / CAM systems: SoildWorks, Pro / ENGINEER, Unigraphics, Solid Edge, CATIA, Inventor, AutoCAD, T-FLEX CAD; and etc.

TechnoKom interface carries out data exchange and synchronization. This interface is customizable on a turnkey basis, taking into account the configuration of PDM and ERP systems in a particular enterprise. This approach allows you to organize complexes that include TechnoPro and the following systems:

PDM - SmarTeam, Windchill, Teamcenter, Party PLUS, PDM Step Suite, T-FLEX Docs;

ERP - Baan, SyteLine, OneWorld, Sap R / 3, Scala, Mfg / Pro, Axapta, Navision, Galaxy, Omega, Best-Pro, 1C;

Other systems, including those developed by the forces of the customer's enterprises.

ADEM(integrated CAPP / CAD / CAM system). Russian developer - Omega ADEM Technologies Ltd.

An integrated ADEM system that entered the domestic and foreign markets in the mid-90s. XX century., Appeared as a result of scientific research carried out jointly by specialists from Russia, Israel and Germany. The task of these studies was to determine the parameters of a software package for automating the bulk of design and engineering work for machine-building enterprises.

The ADEM complex consists of several modules:

ADEM CAPP - TP design system, which allows with varying degrees of automation to develop single, group and typical TP in many areas (machining, electroplating, welding, assembly, heat treatment, etc.);

ADEM CAD - a design tool that combines well-known methods of geometric 2D and 3D (solid and surface) modeling;

ADEM CAM - preparation of control programs for CNC machines;

ADEM Vault - an electronic archive of technical documents that allows you to combine in one information space the work of designers, technologists and other participants in the design and technological preparation of production;

ADEM TDM - instrumental environment designed for the development of custom applications.

In the ADEM CAPP system, an attempt is made to increase the efficiency of technological design by:

Friendly user interface (presentation of TP in the form of a tree, context-sensitive menu, etc.);

Integration with other modules of the system;

Use of effective methods and techniques for modifying the structure and composition of TP;

Possibilities of saving parts of TP (operations, transitions, etc.) for the purpose of their further use;

Possibilities of using the general reference information for the enterprise, which is relevant at any time of the design.

The input information about the part for which the TP is designed (designation, name, information about the material, etc.) is either imported from a CAD system, or manually entered from the keyboard. The selection of information from the reference books of the system database is provided.

The sequence of operations (route TP) is determined by the user-technologist. The names of operations and equipment are selected from the appropriate directories. An operation sketch or setup sheet can be associated with each operation. A drawing or sketch can be prepared both in the ADEM system and imported from other systems. For this ADEM contains a number of built-in converters (DXF / DWG, SAT, IGES, STEP, etc.). It is possible to design TP based on typical TP-analogs by modifying the structure and parameters of the latter by editing them.

The transitions that form the operations are conventionally divided into three groups: installation, basic and technical control. The main transitions correspond to the specific operation selected. When forming the transition text, the technologist can use the drawing (chipping of dimensions and other various text information). The system calculates the main transition time based on the cutting data set or defined in accordance with the standards.

When choosing technological equipment, databases of devices, auxiliary, cutting, locksmith, measuring (universal and special) tools are used.

All information entered and received in the process of designing the TP is placed in the layouts of technological documents. Layouts are created in the ADEM CAD module, so no additional software is required to create and view them. A set of layouts is standardly supplied with the ADEM system to form a complete set of technological documentation in accordance with the ESTD.

ADEM CAM module provides preparation of control programs for turning, milling (with control in 2.5 - 5 coordinates, including high-speed ones), EDM (with control in 2-4 coordinates) and other machines with a wide range of control systems.

TECHCARD(a set of automation tools for the Chamber of Commerce and Industry). Developer - NPP INTERMEKH (Republic of Belarus). As the system center of Autodesk, SPE "INTERMECH" supplies domestic enterprises, in addition to the specified complex, a wide range of software products, in particular:

SEARCH - a system for maintaining an archive of technical documentation of enterprises and managing product data;

CADMECH - multifunctional application for 3D modeling systems;

ROTATION - a system for designing parts such as bodies of revolution;

LCAD - software development automation software package
technological planning of production workshops and sections.

The TECHCARD complex for organizing a technologist's workplace includes:

CAD TP for manufacturing parts for various types of industries (machining, heat treatment, welding, assembly, electroplating, painting, etc.);

CAD of mechanical engineering drawings for the construction and design of operational sketches or any graphic images entered into a technological document, working in the AutoCAD environment;

System for organizing and maintaining an archive of design and technological documentation;

Technological database, which includes time standards for main and auxiliary work; illustrated classifier of equipment with an indication of its characteristics and location in workshops and sections; illustrated classifier of technological equipment with an indication of their characteristics; data on the main, auxiliary materials, types of blanks and their applicability; classifier of technological operations and typical transitions; reference data for determining the parameters of the operating technology; libraries of typical TP; recommended cutting conditions.

The design of the TP is performed in an interactive mode using TP-analog or using a database. It is possible to organize parallel design of end-to-end TP by several performers for various types of production. The selection of tooling, equipment, materials and performers is carried out in an automated mode according to user-configurable algorithms. Development of standard and group TPs is possible.

The complex allows you to work on separate specialized AWPs (a shop assistant for creating and editing shop routing routes; specialists in material and labor rationing; tooling designer; translator of technological documents into foreign languages).

Technological documentation is formed in full compliance with applicable standards. It is possible to create any new forms of documents and maintain an archive of technological documentation through interconnection with the SEARCH system.

The complex integrates with any management and planning system used or chosen at the enterprise. It is intended for use in technological departments, both large enterprises and small industrial organizations that use the workstation of technologists based on personal computers and local networks. Powered by industrial DBMS Oracle / Interbase / MS SQL.

The increasing complexity of the designs of parts, the need to use control along several coordinates in the shaping processes, the sharp complication of the shaping trajectories implemented on CNC equipment, require constant improvement of the systems for the automated preparation of control programs (SAP). In fig. 7.1 shows a diagram of the modern preparation of control programs for CNC machines using automation. In one form or another, this scheme is implemented with the use of almost all SAP. Let's consider examples of some systems used in modern domestic mechanical engineering.

EdgeCAM. The developer is CJSC Russian Industrial Company. Designed to automate the preparation of control programs for turning, milling, EDM and other CNC machines. It is implemented at the workstation of the technologist-programmer with the support of 3D models of parts.

The 3D model of the part is developed by the designer using AutoCAD, CADMECH, Inventor programs. At the end of the development, the design documentation and the model of the part are sent to the Search archive, which is located on the general server of the organization. When a job is received for the manufacture of this part, the programmer-technologist, using the design documentation and the 3D model of the part, develops the operating technology and the corresponding control program in the EdgeCAM system.

At the end of the work, the control program is copied over the local network to the program control server. When a workpiece arrives, the operator of CNC machines calls the program from the server and, after checking and setting up the machine, starts processing the workpiece.

GeMMa-ZB(geometric modeling and programming system for CNC machines). Developer - STC GeMMa.

Provides preparation of control programs for turning, milling (2-, 3-axis machining), EDM (2-, 4-axis machining), engraving machines with CNC, as well as equipment for laser plasma cutting and sheet-punching processing. The system implements the functions of surface treatment according to various strategies, which is important for the manufacture of parts according to models imported from other systems. It is possible to permanently correct the feed rate when working out complex paths in order to optimize cutting conditions and ensure high quality processing.

FeMMa-3D works in a single technological complex with the KOMPAS 3D system. The model of the future product is built in KOMPAS 3D, and then transferred to the FeMMa-3D system, where a program for CNC machines is created for the manufacture of this model.

The interface with other systems is implemented through the widespread standard IGES format, which is available in almost all Russian and foreign CAD systems. This format allows you to transfer any geometry built in the design system. The model transferred to the FeMMa-3D system, without any modifications, can serve as a basis for building control programs for a CNC machine.

A computer with the GeMM system can be connected directly to the CNC device. The system has its own macro programming language GML (Gemma Macro Language), designed to create macro procedures (macros). With the help of macros, at the request of users, the procedures they need can be described that do not fit into the framework of an already operating system, for example, tool movement cycles that are not provided for by the basic system configuration.

Analysis of the state of domestic means of automated support for the life cycle of mechanical engineering shows that the domestic market is developing dynamically. The range of automation tools is expanding, their quality is constantly growing, and their functions are expanding. More and more possibilities are presented to users of automated systems.

The development of automation tools is becoming more and more complex. An increasing number of developers create and put on the market integrated systems CAD / CAM / CAPP, CAD / CAM / CAPP / PDM, etc. The problem of system integration, the creation of a unified information space for supporting life cycle services or even managing it is one of the urgent problems in the development of modern automation tools ... One of the most important directions of improving automated systems is connected with the solution of this problem.

The improvement of systems is uneven. The greatest success was achieved by the developers of CAD K and CAD (CAD-, CAM-, CAD / CAM-systems). On the basis of powerful cores of geometric modeling, very advanced 2D and 3D modeling systems (surface and solid) have been created. The problem of automating the preparation of control programs for CNC machines should be considered solved in principle. Modern SAP allows developing control programs for 2 - 5-coordinate processing with visualization of the trajectory of the relative movement of the tool and automated control of the program.

At the same time, the level of CAD-, CAM-, CAD / CAM-systems of domestic development is still inferior to the best foreign counterparts. In the domestic market of automation software, foreign systems of these classes, despite their relatively high cost, still successfully compete with domestic ones. Some domestic systems use basic software from foreign developers, for example, geometric modeling kernels. All this indicates the need for constant work to improve and raise the level of the systems under consideration.

A significantly larger number of unsolved problems are associated with the automation of the design of TP. Almost all domestic CAD TP (CAPR systems) do not allow today to fully automate the development of route TP for manufacturing a part, not to mention the assembly. In modern ASP, they mainly use the design of route TP based on analogs (typical, group TP, parameterized TP models, “general” TP for a group of parts). Various methodological approaches are used: level representation of TP, representation of TP in the form of "trees", etc. The role of the technologist-designer remains decisive, since he forms the route TP, based on his own knowledge, experience, intuition, will prefer (often erroneous) ones. The design decision is subjective.

Meanwhile, TP is, first of all, route TP and accompanying additional information about the place of its implementation, the equipment used, and the expected labor costs. The developed TP is a carrier of information that is used in the future by various divisions of the enterprise to manage current production, analyze and forecast new ones.

It is the formation of the route TP and the determination of the means of technological equipment that is truly creative. Everything else is a derivative of this process. However, it is at this, the most important design stage, that existing CAD TPs practically do not provide the technologist with the necessary intellectual support. All subsequent design stages are less complicated, but involve a significant amount of routine work - preparation of technological documentation, drawing up various statements and specifications. These functions are successfully automated in modern CAD TPs.

It can be argued that the overwhelming majority of existing CAD TP (both domestic and foreign development) are automation systems at the technological level; operations. These systems make it possible to increase the productivity of a technologist by automating routine work associated with the design process, streamlining the relationships of designers in the process of work, providing a wide range of convenient service functions for maintaining automated archives, etc. These factors contribute to improving the quality of work of technologists, as they streamline their work and allow you to focus more attention on making effective technological decisions.

However, the main reserve for improving the quality of design technological solutions - the formation of their highly efficient structures, is currently unused in the creation of CAD TP.

The similarity and non-originality of the scientific and methodological approaches used in the development of systems makes some CAD TPs similar and hardly distinguishable in terms of capabilities, which significantly reduces their competitiveness.

The level of automation in a number of areas of technological design, for example, the development of TP assemblies with the selection of the necessary methods for ensuring its quality, remains extremely low. Some systems that claim to automate the design of assembly processes, in fact, offer the user only not very convenient text editors with not too fully developed layouts of the texts of individual transitions and operations. The actual design of the TP is performed by a person with minimal information and intellectual support of the system.

The reasons for this state of automation of technological design are the complexity of the set automation problems; the nature of tasks that is not formalized at the current level of development of the methodology of computer-aided design; lack of effective scientific and methodological approaches to their solution, and sometimes the lack of awareness of developers about the availability of such approaches; the need for significant costs for solving the problems posed, etc.

The objective course of development of engineering, technology and automation means makes the solution of the set design automation problems extremely relevant, which determines the main directions for improving the CAD TP.

The production process is a set of actions of people and tools of production necessary for the manufacture of a product. Product - any item or set of production items to be manufactured in an enterprise. Place of CAD TP in the system of technological preparation of production To prepare the enterprise for the release of new products, it is necessary to perform a set of works.

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Lecture 1. Basic concepts and place of CAD TP in the system of technological preparation of production, functions of CCI

1.1. Basic concepts

The computer-aided design of technological processes (CAD TP), as the name implies, is intended for the design of a technological process. Let's consider the concepts included in this definition.

Design - development of a description of a not yet existing object for its creation according to this description.

Objects can be a technical system (machine tool), processes (technological process), phenomena, i.e. processes occurring in a short period of time (thermal phenomena).

We are, of course, interested in the design of the technological process.

The purpose of designing a technological process (the purpose of developing its description) is to obtain for engineering and technical personnel and workers of production units (workshops, sections) a sufficiently detailed description of technological methods for manufacturing a product, indicating the order of their implementation and the calculated values of the rates of consumption of materials, time, processing modes ...

The description of the TP includes a route map, operational maps, operational sketches, a list of equipment. All this technological documentation must be obtained using CAD TP.

The route map is a list of technological operations with an indication of the equipment model by operations in the order of their execution. The operating chart provides a description of the transitions with an indication of the cutting tool. Equipment, tools are associated with the concept of the production process.

Manufacturing processis a set of actions of people and tools of production necessary for the manufacture of a product.

The production process includes not only processes directly related to changing the shape and properties of the processed parts, assembly of units and products, but also all the necessary auxiliary processes: warehousing, packaging, shipment of products; repair and modernization of equipment; manufacture of tools and means of mechanization; control at all stages.

Product - any item or set of production items to be manufactured in the enterprise.

Detail Is a product made of a material of the same name and brand without the use of assembly operations.

Technological process (TP)- This is a part of the production process, containing targeted actions to change the state of the object of labor (workpiece) and obtain a product with desired properties.

Technological reception- this is a specific, theoretically or empirically (based on facts) a certain prevailing behavior of personnel in the manufacture of a product using some means of technological equipment.

Technological process of mechanical processing- this is a part of the production process, which includes sequential actions to transform the original workpiece into a finished part by changing the shape, size, condition of surfaces by processing with metalworking tools.

Technological operation- a part of the technological process performed at one workplace and covering all the techniques and actions of the equipment and the worker over one or more jointly processed objects of labor.

Technological transitionIs a technological technique, which is part of an operation, performed when processing one or more sections of the surface of a part with the same tool or a group of tools without changing the processing mode.

This definition is fully applicable only for operations performed on conventional equipment. When machining workpieces on machines with adaptive control, the machining modes can change during one pass.

Technological passage- part of the transition, which consists in removing one layer of material from the treated surface.

Description of the technological process- this is a presentation in a certain language of a method for manufacturing a product, consisting of an ordered set of descriptions of technological methods, including information about the types and modes of operation of the technological equipment used, technological instructions, time rates and rates of material consumption, and drawn up according to established standards.

Description of TP can be developed "manually", without using automation tools.

The development of a TP description using automation means is an automated development. Automation tools include a computer and programs. The software package is called "Computer-aided design TP". If you decipher the word "design", you get "a system for the automated compilation of TP descriptions." At enterprises, the description of TP is simply called "the technological process of manufacturing a part."

1.2. Place of CAD TP in the system of technological preparation of production

To prepare the enterprise for the release of new products, it is necessary to perform a set of works. These works are called technical preparation of production. Technical preparation of production is divided into 3 parts (Figure 1.1):

Design training (development of blueprints for a new product).
Organizational preparation (calendar and technical and economic planning).
Technological preparation.

Rice. 1.1. Structure of technical preparation of production

Technological preparation of production (TPP) is a set of works aimed at preparing production for the release of new products according to the existing drawings, release program, and timing.

1.3. The main tasks of the CCI

Let's consider the main tasks of technological preparation of production.

Ensuring the manufacturability of the design of products.To solve this problem, the following are carried out: structural analysis of products (which parts and assembly units are included in the product) in order to determine the possibility of increasing the number of borrowed parts (including standard ones); technical and economic analysis of production (what technological processes and means of technological equipment can be used from the processes and means of preparation of technologically similar and already launched products); analysis of the possibility of improving the manufacturability of the design of parts.

Manufacturability in accordance with GOST 18831-73 is considered as a set of product design properties, manifested in the possibility of optimal labor costs, funds, materials and time in the technical preparation of production, manufacture, operation and repair, in comparison with the corresponding indicators of the same type of product designs for the same purpose while ensuring the established values of quality indicators in the accepted conditions of manufacture, operation and repair.

Analysis of the possibility of improving the manufacturability of the design of parts includes the analysis of the possibility of: reducing the size of the processed surfaces to reduce the labor intensity of machining; increasing the rigidity of the part to ensure its multi-tool processing and high-performance cutting conditions; facilitating the approach and withdrawal of cutting tools in order to reduce auxiliary time; unification of the sizes of holes, grooves and grooves to reduce the range of tools; ensuring convenient and reliable basing of workpieces, and when setting dimensions, analysis of the possibility of combining technological and measuring bases; analysis of the convenience of performing multi-site processing of workpieces.

Indicators for assessing the manufacturability of the structure are taken into account the requirements of GOST 14.201-73. Manufacturability of a design is a relative and complex concept. When assessing it, one should take into account the conditions of production (type, level of automation and equipment), it cannot be considered in isolation, without interrelation and taking into account the conditions for the implementation of preparatory processes, processing, assembly and control processes. Testing for the manufacturability of the design is carried out in order to obtain the least labor intensity and the cost of manufacturing the product as a whole.

Improving the manufacturability of the design makes it possible to reduce the labor intensity of manufacturing the product by 15–30% or more, and the cost price by 10–20%. For individual parts, these figures may be higher.

The concept of "manufacturability of a design" is extended not only to the area of production, but also to the process of its preparation. The design of the product should be convenient for its rapid development in production, as well as for its operation by the consumer (ease of maintenance, maintainability, economy of operation).

It is recommended to work out the design of the product for manufacturability in the process of creating the design itself. At the same time, working contact of designers and technologists is achieved, and the duration of the subsequent development of technological processes is reduced.

Development of technological processes (TP)... The purpose of the TP design is a detailed description of the product manufacturing processes with the necessary technical and economic calculations and justifications for the adopted option. This main task of the technologist is complemented by the task of implementing the designed technological process at the enterprise. As a result of the preparation of technological documentation, engineering and technical personnel and working performers receive the necessary data and instructions for the implementation of the designed technological process in specific production conditions.

Technological processes are developed during the design of new and reconstruction of existing plants, as well as when organizing the production of new products at existing plants. In addition, TP are corrected or new TP are developed at existing factories when producing already mastered products. This is due to the constructive improvements of manufactured products and the need to use and introduce advanced technology and the latest achievements in production technology into existing production.

When designing new and reconstruction of existing plants, the developed TP are taken as the basis for the project. They determine the necessary technological equipment, production areas and energy capacity of the workshop, its vehicles, the number of workers, basic and auxiliary materials. On the basis of the projected TP, initial data are established for organizing shop supplies, scheduling, technological control, instrumental and transport facilities, and issues of organization, economics and shop management are resolved. The technical and economic indicators of the plant depend on the quality of technological developments.

When organizing the production of new products at an operating plant, the development of TP precedes all preparatory and organizational work. On the basis of TP, the possibilities of using existing equipment and the need to purchase new ones are identified, the additional labor force required, the number of tools, technical controls, vehicles, materials, energy are determined.

The task of designing TP is characterized by the multivariance of possible solutions. Even for relatively simple products, several different TPs can be developed that fully meet the requirements of the working drawing and technical conditions. Comparing the efficiency and profitability of these options, one or more equivalent options are finally selected.

From these several possible options, first select those whose performance is not lower than the specified one. Then the most cost-effective option is chosen, which ensures the minimum cost of manufacturing the product.

TP design is complex and labor-intensive. It is performed in several successive stages. First, preliminary sketches are made when solving particular and general design issues; at subsequent stages, these outlines are refined and concretized on the basis of detailed technological calculations. Knowledge of the basic laws of construction of TP and mathematical methods make it possible to find optimal solutions using computer-aided design methods.

The main difficulties in optimizing the solution of complex technological problems are the presence of a large number of influencing factors and the absence of exact patterns in the course of technological processes.

Design and manufacture of technological equipment (STO)... The service station includes machine tools, cutting, measuring and auxiliary tools.

The design of technological equipment includes the solution of design and technological problems. The main directions of automation of solving these problems: typification of constructive and technological solutions; separation of the problematic part from the invariant; creation of data banks for design and technology purposes; the use of interactive design methods. On this basis, special subsystems for the automated design of technological equipment are being developed. Known subsystems for the design of stamps, casting molds, devices for drilling flat parts, photomasks, printed circuit boards, cutting, measuring and auxiliary tools, etc.

1.4. Functions and means of automation of the CCI

Let's consider the CCI as an automation object. To automate the CCI is to automate the following functions in a complex (Fig.1.2):

analysis and ensuring manufacturability of product design;
technological analysis of production;
TP design
design of technological equipment (STO);
preparation of control programs (UP) for CNC machines;
rationing of labor and materials;
design of sites, workshops;
CCI planning and management of the CCI process;
manufacturing of service stations.

By their properties, functions are heterogeneous and are automated using various methods and means.

In fig. 1.2 the main systems are indicated, with the help of which the automation of the CCI functions is realized. Automation tools include ISS - information retrieval systems; CAD TP - computer-aided design systems TP, service station, workshops; SAP - a system for automated programming of control programs for CNC machines; SAN - automated rating system; ACS - automated control system of the Chamber of Commerce and Industry. All these systems are part of the ASTPP - the automated system of the Chamber of Commerce and Industry - and are its subsystems.

CCI in the system of technical preparation of production takes 30-40% of the entire complex of works in small-scale production, and 50-60% in mass production. Taking into account the share of manual design, computer-aided design of TP in the Chamber of Commerce and Industry is approximately 25% of the complex of all works in the Chamber of Commerce and Industry.

Questions for lecture 1

What is design?
Define the manufacturing process.
Define the technological process.
Give a definition of a technological operation and transition.
What actions of people and tools of production does the technological process include?
What is the peculiarity of TP machining?
What kinds of TP descriptions do you know?
What methods are used to develop a description of TP?
Give the definition of CAD TP.
What is the purpose of technical preparation of production?
What are the functions of design preparation for production?
What are the functions of technological preparation of production?
What percentage of CCI work is done using CAD TP?

PAGE 1

Rice. 1.2. Functions and means of automation of the CCI

Automation tools

ACS CCI

CAD workshop

SAN

GLANDERS

CAD STO

CAD TP

Automated equipment and tooling

IPS

Manufacturing of service stations

Planning and management of TP

Workshop design

Rationing

Preparation of UE

Service station design

TP design

Production analysis

Ensuring the manufacturability of the product

Functions of the CCI

Design preparation of production

Organizational preparation of production

Technological preparation of production

Technical preparation of production

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Analysis of the functionality of CAD TP used for automated design of TP

Currently, there is a large variety of CAD systems from various development firms that allow organizing design and technological preparation of production. Various subsystems of companies developing computer-aided design systems were studied: ADEM, PRO Technologies, CSoft group of companies, Dassault Systemes (HETNET Consulting - Russian representative), CNC Software Inc., SolidWorks Corporation, Ascon, Top Systems, Vector-Alliance corporation, etc. etc.

The formulated topic of the dissertation work determined the need to analyze the functionality of computer-aided design systems focused on the preparation of workpiece processing technology. The following CAD TP were analyzed: TechnoPro, T-Flex Technology, SPRUT-TP, Techcard, ADEM CAPP, TechnologiCS, SolidWorks, pro / Engineer, Unigraphics, CATIA, Cimatron, NX, EUCLID, I-DEAS, Mastercam, AutoCAD 2000, Mechanical Desktop, Vertical, Autodesk Inventor, Powermill, Bravo product family, IronCad, MicroStation Modeler, CADKEY 99, pro / Desktop, SolidWorks, Anvil Express, Solid Edge, etc.

Let us present a description of the functionality of some analyzed CAD TP.

Techcard is a software and methodological complex of design automation systems used in the technological preparation of production. In fig. 1.7 shows the graphical interface of the program.

Rice. 1.7. Graphical interface of the program "Techcard"

Let's list some of the main features of the program. Techcard allows you to: draw up the necessary documentation when creating technological processes (TP); carry out technological calculations, automatically select equipment and tooling for operations and transitions using a customizable expert system; create and draw up operational sketches or graphic images that are included in the technological document; design TP for processing a part: based on an analogue part, using a library of typical fragments, using typical TP, etc.

T-FLEX Technology- a program for the automation of technological preparation of production, which has flexible modern tools for the development of technological projects. It is intended for the automated development of route, route-operational and operational technology.

In fig. 1.8 the graphical interface of the program is presented.

Rice. 1.8. Graphic interface of the "T-FLEX Technology" program

The program generates title pages, route, route-operational and operational charts, statements and other necessary technological documents. Information base T-FLEX Technology contains a large number of reference books on the components of technological processes.

The program supports various methods of designing TP: interactive design using technological databases; design based on the analogue technical process; borrowing technological solutions from previously developed technologies; design using a library of technological solutions; design of group and typical technological processes from the general technological process; automatic design using a library of technological solutions.

Vertical- A computer-aided design system for technological processes, which solves the problems of automation of the processes of the Chamber of Commerce and Industry. In fig. 1.9 shows the graphical interface of the program.

Rice. 1.9. Graphical interface of the program "Vertical"

CAD TP Vertical allows you to: design technological processes in an automated mode; calculate material and labor costs of production; to form sets of technological documentation used at the enterprise; organize and develop technological databases of the enterprise; transfer data to various planning and management systems (classes PDM \ MRP \ ERP).

Here are the main design methods of TP implemented in the CAD TP Vertical: design based on the analogue technical process; design using a library of technological solutions; design using a library of design and technological elements (KTE); automatic generation of TP fragments based on standard plans for CHP processing; interactive design mode using system databases.

As a result of the analysis, the main functional capabilities of the existing CAD TP were identified. These possibilities include the following methods of compiling technology: designing TP based on an analogue technical process; interactive design using technological databases; borrowing technological solutions from previously developed technologies; design of group and typical technological processes. Also in each of the considered CAD systems there are additional features: the formation of design and technological documentation; use of technological reference books, which contain information about technological equipment, cutting and measuring tools, etc .; integration with other CAD systems; designing programs for machine tools with numerical control; the possibility of preserving the processing technology and the use of the accumulated TP bank for the preparation of new technological processes.

In the thesis under consideration, the tasks of the automated synthesis of possible basing schemes and the choice of rational ones from them were posed. As you know, such tasks are part of the large task of forming a technological process for processing a workpiece. The solution of such problems in the existing CAD TP is carried out on the basis of standard solutions or is completely absent. Thus, the proposed methodology and algorithm for finding rational basing schemes are innovative and have no implementation in existing CAD systems.

Analysis of Mathematical Methods for Making Technological Decisions in the Context of Multi-Criteria Choice

The choice of rational basing schemes from a set of possible schemes is a classic decision-making problem. The decision-making problem (DM) arises when there are several alternatives, from which you need to choose one or more that satisfy the decision-maker (DM).

To build a software package for the automated selection of rational workpiece basing schemes, it is necessary to consider the existing mathematical methods that can help in solving the problem.

Consider the following decision-making methods:

multicriteria utility theory (MAUT);

SMART method;

analytical hierarchy method (MAI);

methods for ranking multi-criteria ELECTRE alternatives.

Multi-criteria utility theory (MAUT)

Let us present the stages of solving the problem using the MAUT (Multi-Attribute Utility Theory) approach.

A list of criteria is being developed.

A utility function is constructed for each of the criteria.

Certain conditions are checked that determine the form of the general utility function.

A relationship is built between the assessments of alternatives by criteria and the overall quality of the alternative (multi-criteria utility function).

The usefulness of each alternative is determined and the best one is selected.

The multicriteria utility theory has an axiomatic foundation. This means that certain conditions (axioms) are put forward that must be satisfied by the decision maker's utility function. In MAUT, these axioms can be divided into two groups: general; independence. The first group includes the following axioms:

the axiom of completeness, which states that a relationship can be established between the usefulness of any alternatives (either one of them is superior to the other, or they are equal);

the axiom of transitivity, which says that from the superiority of the utility of the alternative A B and superiority of utility B over utility C the superiority of the utility of the alternative follows A over the usefulness of the alternative C;

the axiom of continuity is based on the assumption that the utility function is continuous and that any small portions of the utilities of the alternatives can be used.

The second group, which is called the axioms of independence, allows us to assert that some relationships between assessments of alternatives by criteria does not depend on the values of other criteria.

Here are some conditions for independence.

Independence by difference. Preferences between two alternatives that differ only in their ratings on the ordinal scale of one criterion C 1, do not depend on the same ratings on other criteria C 2 , …, C N .

Independence in usefulness. Criterion C 1 is called utility independent of the criteria C 2 , …, C N if the order of preferences of lotteries in which only the levels of the criterion change C 1, does not depend on fixed values for other criteria.

Independence by preference. Two criteria C 1 and C 2 independent of preference from other criteria C 3 , …, C N if the preferences between the alternatives differing only in the estimates for C 1 , C 2, do not depend on fixed values for other criteria.

If the axioms of the first and second groups are fulfilled, then this implies a strict conclusion about the existence of a multicriteria utility function in a certain form.

Here is the main theorem of multicriteria utility theory, on which practical methods for evaluating alternatives are based.

If the conditions for independence in utility and independence in preference are satisfied, then the utility function is additive:

or multiplicative

where U, U i- utility function, varying from 0 to 1;

w i Is the coefficient of importance (weight) of the criteria, and 0< w i < 1; коэффициент k > -1. Thus, the multicriteria utility function can be determined if the values of the coefficients are known w i , k, as well as one-criterion utility functions U i (x).

The determination of the coefficients of the importance of the criteria occurs through the search for points of indifference on the planes of the two criteria.

After finding the weights of the criteria and constructing one-criterion utility functions, the utility of each alternative is determined according to the selected function.

SMART method

As a reaction to the complexity of MAUT-based methods, one can assess the emergence of a number of heuristic methods that do not have a strictly mathematical justification, but use simple procedures for obtaining information and its aggregation into a general assessment of the alternative.

One of the most famous methods of this type is the SMART method proposed by W. Edwards. In order to evaluate alternatives using the SMART method, you must:

order criteria by importance;

assign the most important criterion a score of 100 points; based on the pairwise ratio of criteria in importance, give a score for each of the criteria;

add up the received points; normalize the weights of the criteria by dividing the assigned points by the sum of the weights;

measure the value of each alternative for each of the criteria on a scale from 0 to 100 points;

Determine the overall rating for each alternative using a weighted sum of points formula;

choose as the best alternative with the highest overall rating;

evaluate the sensitivity of the result to changes in weights.

Hierarchy Analysis Method (HAI)

With the MAUT approach, the same decision maker's efforts to construct the utility function can be spent with a large and small number of alternatives. In the case of a small number of given alternatives, it seems reasonable to direct the efforts of the decision maker to compare only the given alternatives. It is this idea that underlies the method of analysis of hierarchies (AHP or Analytic Hierarchy Process - AHP) developed by T. Saaty.

The solution process by the MAI method can be represented by a set of stages.

In pairwise comparisons, the decision maker is given a scale of verbal definitions of the level of importance, and each definition is assigned a number (Table 1.5).

The scale also contains intermediate grades for more accurate gradation and inverse grades such as: 1/3, 1/5, 1/7, etc.

As a result of pairwise comparison of the criteria, we obtain the weight coefficients w i for each criterion. To determine the importance j-th alternative for i-th criterion is applied the same technology as for the evaluation of the criteria.

Table 1.5

Relative importance scale

Importance level	Quantitative value
Equal importance
Moderate superiority
Substantial or strong superiority
Significant superiority
Absolute superiority

The choice of the best alternative is calculated by the formula:

where S j- level of quality j th alternative; N- the number of criteria; w i- the weight i-th criterion; V ji- importance j-th alternative for i-th criterion.

When pairwise comparison of criteria and alternatives, the decision maker can make mistakes. One of the possible errors is the violation of transitivity: from
may not follow
... Another mistake can be a violation of the consistency of numerical judgments:

To detect inconsistency, a computation of the consistency index of comparisons is proposed.

Methods for ranking multi-criteria ELECTRE alternatives

A group of French scientists led by Professor B. Roy proposed a new approach to the problem of decision making under many criteria. In foreign literature, it is known as the "king approach", in the Russian literature the name RIPSA is used - an approach aimed at developing pairwise comparison indices. Many methods are based on this approach, the most famous is the ELECTRE group of methods (Elimination Et Choix Traduisant la Realite - exclusion and choice reflecting reality).

In contrast to the MAUT and AHP methods, the RIPSA approach assumes that the decision maker forms his preferences during the analysis of the problem. Thus, the method presents the decision maker with various options for solving the problem, depending on certain decision rules. These rules are formed as indices of pairwise comparison of alternatives.

In the RIPSA approach, it is customary to distinguish between two main stages:

development stage, at which one or more indices of pairwise comparison of alternatives are built;

the stage of research, at which the constructed indices are used to rank (or classify) a given set of alternatives.

The indices of pairwise comparison of alternatives in most methods are based on the principles of agreement and disagreement. In accordance with these principles, the alternative A i is at least not worse than the alternative A j, if:

a sufficient majority of the criteria support this statement (principle of consent);

objections on other criteria are not too strong (principle of small disagreement).

At the moment, many ELECTRE methods have been developed based on the RIPSA approach. Here is a description of only the ELECTRE I method.

In the ELECTRE I method, the indices of agreement and disagreement are constructed as follows. Each of N criteria is matched with an integer w characterizing the importance of the criterion. Further, a hypothesis is put forward about the superiority of the alternative A i over alternative A j... Lots of I consisting of N alternatives is broken down into three subsets:

I+ Is a subset of criteria by which A i preferable A j ;

I= Is a subset of criteria according to which A i is equivalent to A j ;

I- is a subset of criteria by which A j preferable A i .

where
- assessing alternatives A i , A j by the i-th criterion; L i- scale length i-th criterion.

Comparing the alternatives in pairs, the matrices of the indices of agreement and disagreement are constructed. Next, the levels of agreement and disagreement are set, with which the calculated indices for each pair of alternatives are compared. If the index of agreement is higher than a given level, and the index of disagreement is higher, then one of the alternatives is superior to the other. Otherwise, the alternatives are incomparable.

The dominant ones are removed from the multitude of alternatives. The remaining alternatives form the first core. Weaker values of the levels of agreement and disagreement are introduced (a lower level of agreement and a higher level of unconformity), at which kernels with fewer alternatives are distinguished. The latest kernel contains the best alternatives. The sequence of kernels determines the ordering of the alternatives in terms of quality.

Analysis of the possibility of using the presented decision-making methods in the problem of choosing rational basing schemes

The applicability of the MAUT method largely depends on the observance of the independence conditions. If the conditions are not met, then the use of this method is either impossible or difficult, since it requires splitting the criteria into a subgroup of independent criteria. The conditions of independence must be checked in a dialogue with the decision maker in relation to each alternative or pairs of alternatives (the condition of independence by preference). The use of this method will complicate the decision-making process for the decision maker and significantly increase its time.

Despite the obvious ease of use of the SMART method, it has disadvantages. The expert is asked to rank the criteria by importance, but errors often occur due to the lack of transparent mechanisms for comparing criteria. According to the author of the method, this method does not take into account the possible dependence of measurements and non-additivity when determining the total value of the alternative. As well as when comparing criteria on the selected rating scale, the measurement of alternatives for each of the criteria is subjective and errors are possible due to the fault of an expert.

The main difference between the ELECTRE family of methods and the considered decision-making methods is that the preferences of the decision maker are not formed before the application of the method, but are formed during the analysis of the problem. ELECTRE methods allow one to present various solutions to the problem, depending on the decision rules. In the problem of choosing rational basing schemes, the preferences of the decision maker will be known before the start of the analysis. To rank the criteria, they will be formed at the stage of setting up the automated system. When comparing alternatives, it is assumed not to resort to the help of an expert (technologist), but to solve this problem in an automatic mode on the basis of developed mechanisms (methods and algorithms). In this case, you do not need to resort to decision rule tools that allow you to adjust the choice of alternatives by changing the comparison indices.

Currently, one of the most popular decision-making methods is the Hierarchy Analysis Method (HAI). Practical examples of this method have been published in various journals. In the method of analyzing hierarchies, first of all, one can single out a general scheme for structuring the task: goals-criteria-alternatives. At each level of the hierarchy, pairwise comparison of level elements is carried out using a verbal scale of relative importance.

As a result of comparing alternatives using this method, each alternative receives a quantitative assessment, which is convenient to use for further stages of the problem consideration. With regard to the dissertation problem, the obtained quantitative assessment of the basing scheme (alternatives) can be used not only for choosing rational schemes, but also for other stages of technological preparation of production, for example, choosing the optimal technological process.

On the basis of the performed analysis of mathematical decision-making methods, it seems more expedient to use the MAI for solving the problem of choosing rational basing schemes, since this method has sufficient clarity and simplicity of calculations, and also makes it possible to set the weighting factors for the selection criteria.

The purpose and objectives of the thesis

In the first chapter of the dissertation, the methods of automated design of TP and their development trends were considered. The main attention is paid to the presentation of the initial information for the design of TP, since the study of this issue will not only save time in the development and further development of the software package, but will also allow solving other technological problems on the basis of the presentation of the initial information.

The performed analysis of the existing functional capabilities of CAD TP made it possible to more accurately formulate the requirements for the designed software package, as well as to identify a set of available software tools to achieve the intended goal.

Analysis of existing methods and algorithms for choosing rational basing schemes made it possible to identify their shortcomings, emphasize the accumulated experience in solving such problems, and formulate subtasks to be solved.

Mathematical methods of decision-making in the context of multicriteria choice were investigated for the possibility of using them in the problem of choosing rational basing schemes. As a result of the research, the hierarchy analysis method was chosen as the most suitable for solving the problem.

As a result of the analysis, the goal of the dissertation work was formulated, which is to reduce the time for designing technological processes for processing a workpiece, by formalizing the procedures for choosing rational basing schemes, using automated systems for technological preparation of production. The stated goal is based on the dissertation topic formulated earlier.

technological process... Clarification ...

Labor protection rules in logging woodworking industries and during forestry work

Document

... automation technologicalprocess... v rational colors... Choice places basing ... workpiece blank wood at ...

Rules for labor protection in logging woodworking industries and during forestry operations (1)

Document

... automation labor should provide comfortable and safe conditions for maintenance and repair, comply technologicalprocess... v rational colors... Choice places basing ... workpiece and cutting pneumatic resin, as well as blank wood at ...

The development of CAD TP can be considered as a process of creation and continuous improvement of the previously mentioned systems. Currently, the main developers of CAD TP are specialized organizations. Systems are supplied to the market as software (software and hardware, software and methodological) complexes.

The implementation, operation and modernization of subsystems and components of CAD TP at enterprises, as a rule, is carried out by specialized subdivisions - departments (services) of CAD, including groups of specialists of the corresponding profiles in close cooperation with developers of CAD TP. The development of the system is carried out by the specialists of the enterprise with the involvement of development specialists, and, if necessary, specialists from other organizations, for example, research institutes and higher educational institutions.

It is fundamentally important to select a group of specialists - direct developers of CAD TP. The technical management of the group should be carried out by a specialist with a basic technological education and deep knowledge in the field of mechanical engineering technology. The development of the system design, the required models and specifications should be carried out by technologists, possibly with the involvement of consultants from industry, research organizations of a technological profile or higher educational institutions. The software and hardware implementation of the system is carried out by programmers. Testing and fine-tuning of the system is carried out jointly by technologists and programmers.

For the organization - the developer of CAD TP, the system being created is a product, which is characterized by the passage (taking into account the specifics) of all the main stages of its life cycle.

At the marketing stage, they investigate the state of the CAD TP market. The purpose of the study is to determine the most relevant market needs, the main trends in the development of CAD TP and scientific and methodological concepts implemented in the existing systems. As a result, the main characteristics of a competitive CAD TP and the basic (conceptual) principles of its construction are determined. Establish an approximate timeline and cost of creating the system. Naturally, they strive to develop a system in the shortest possible time, otherwise competitors may occupy its market "niche". This stage of the product life cycle is completed with the execution of the technical specifications for the development of the system.

Terms of reference is the main mandatory document, with the creation and approval of which the development of CAD TP begins. This document defines the content of the project and the basic requirements for the developed system, the conditions of acceptance and the assessment of its suitability for operation, i.e. the completion of the development. The terms of reference are drawn up in accordance with the requirements of the standards and include the following main sections.

1. Name and scope. This section specifically indicates the main functions that the developed system should perform.

2. Characterization of the system as an object. It is indicated what the physical implementation of CAD TP should be (a package of applied programs, software complex, software-technological and software-methodological complex), as well as its main subsystems (modules).

3. Purpose and structure of development. They represent a generalized structural model of the system being developed, indicating the interrelationships of its main subsystems or elements. In general, they describe the interaction of elements, indicate the content of the input information necessary for the operation of the system and the method of its input.

4. Technical requirements of CAD TP to ensure:

Technical. Indicate the composition, configuration and characteristics of the main technical means on which the system is implemented;

Informational. For software systems, indicate the required composition of the databases used by the developed system during operation;

Software. The operating system is indicated, as well as the name of the underlying programming environment and its version. Disclose the composition of the software of the system being developed;

Organizational. In addition to the development of a set of necessary documents, technical specifications, they describe in detail the procedure for the delivery and acceptance of the development (both within the developer organization and for external customers). Acceptance of CAD TP is carried out according to the results of passing test cases, the content of which is determined by the customer in agreement with the developer.

5. Stages and stages of development. They present a calendar plan (business plan) of work on the creation of a CAD TP, indicating the numbers of the last stages, content, deadlines for each of the stages, cost, forms and types of reporting. The implementation of each stage of CAD TP development is carefully documented in accordance with the standards of the Unified System of Program Documentation. The customer (purchaser) of the system can establish special requirements for it, both in terms of design and in terms of its specialization and adaptability to specific conditions.

The initial stage of CAD TP development corresponds to the clarification of the concept of building the system and the creation of its conceptual model.

The conceptual model defines the main functions of the system being developed and their relationship. When creating it for the developed CAD TP, determine:

Subject area;

Main functions;

The main tasks to be solved when performing the selected functions;

Composition of input and output information;

The main informational links of the selected functions.

The subject area is understood as the area of knowledge used in the formation of the design technological solution by the system. Sometimes the subject area is understood as the specialization (problem orientation) of the system for the formation of design objects of a certain type. For example, CAD of technological operations of turning. If possible, the subject area of the system should be narrow (local). Determining the subject area of the system and its structure is an independent, complex, creative design stage. Semantic networks are often used for this.

One of the main modern methods used in the development of models of various automated decision support systems is the method of structural analysis, presented in the CALS-standard FIPS PUB 183 (IDEFO). In the scientific and technical literature, this method is also called the Ross method, the SA-diagram method, SAD, SADT.

The method assumes a sequential detailing of the designed system "from top to bottom". There are different levels of consideration of the analyzed (designed) system. At each level, the decomposition of the analyzed system is presented, more detailed, but completely equivalent to the previous level. In this case, not only the system is considered, but also its environment, which also undergoes sequential detailing together with the system. A graphic and textual description of a structured system in the form of the necessary diagrams and explanations to them form a model of the system that reflects the latter from a certain point of view.

Input and output data, the name of which is indicated at the corresponding arrows of the top-level model diagram, are determined, as a rule, by the terms of reference for the development of the system.

At the upper levels, the functional partition of the model is carried out without taking into account and choosing implementation methods, i.e. without a picture on the diagrams of the arrow of the mechanism. When the detailing is carried out in sufficient detail and it becomes possible to choose effective means of implementation, then you can return to the choice of the mechanism. The mechanism is not determined not from the input, not from the output, not from the control, and it does not define them, being an independent component of the environment. For top-level models, the content of the control may also be insufficiently certain. In this case, you should use the generalized names of the corresponding arrows, for example, for the models of operations: "information support", detailing their content in the models of subsequent levels.

A system model is a hierarchical set of diagrams (structural diagrams) obtained as a result of its sequential analysis. Each schema is a detail of some object (object or operation) and environment from the schema of the previous (higher level). In this case, the analyzed object is represented on the diagram as a set of objects (no more than 6), depicted in the form of rectangles and connections between them, depicted by arrows of entry, exit and control.

The conceptual model corresponds to the preliminary design stage of the CAD TP.

Conceptual modeling is sometimes performed even before the specification is developed. In this case, fragments of the conceptual model, reflecting the features and differences of the developed CAD TP from the existing ones, are given in the terms of reference.

The next stage in the creation of CAD TP is the development of its functional model.

The functional model describes the functions and structure of the software of the system being developed, being the first document of a technical design. To develop functional models, the method of structural analysis with additions is used to describe not only the functional structure of the system, but also the enlarged structure of the software.

Functional software modules exchange information messages, which are mainly used to launch some modules by others.

The general requirements for the design of functional model diagrams are generally similar to the requirements for the design of conceptual models.

When developing structural diagrams of conceptual and functional models of CAD TP, automation tools are used, for example, the DESIGN IDEF package (a product of Metasoft-ware Corp, USA) or packages for automated analysis of business processes, for example BPWin.

The work of the software modules identified in the functional model can be carried out in interactive (dialog) or batch (automatic) modes. To ensure the implementation of each of the modes in the design of CAD TP, the corresponding documents are developed.

The dialogue of the end user with the software of the developed CAD TP is described in a document called "Dialogue script", developed at the stage of the technical design. The description of the dialogue script is oriented towards the use of a graphical multi-window interface (like Micro soft Windows) and a graphical menu (pictographic interface).

The algorithms intended for implementation in the software of the developed CAD TP are presented in the document "Description of algorithms", compiled at the stage of the technical design. The presented algorithms are referenced from the document "Dialogue script". Together with other documents giving a description (specification) of the system being designed, this document forms a set of interrelated descriptions of a technical project, sufficient for programming an automated system.

The information model of the CAD TP is intended to describe the composition and structure of the information support required for the functioning of the CAD TP. The developer-technologist usually determines only the composition of the information model, without considering its structure (issues of organizing the interaction of information objects, their relationship, organizing data storage, etc.).

At the final acceptance of the developed system, it is tested, for the implementation of which an appropriate program is developed and approved.

After signing the necessary acceptance documentation, the system is considered ready for sale (replication) or operation by a specific customer.

LITERATURE

1. Dialogue CAD of technological processes [Text]: Textbook for universities / V.G. Mitrofanov [and others] - M .: Mechanical engineering, 2000. - 232s.

2. CAD in mechanical engineering technology [Text]: tutorial. - Yaroslavl: Yarosl. state tech. un-t, 1995. - 298p.

3. Kondakov, A.I. CAD of technological processes [Text]: a textbook for students. higher. study. head / A.I. Kondakov. - M .: "Academy", 2007. - 272s.

4. Suslov, A.G. Scientific foundations of mechanical engineering technology [Text] / A.G. Suslov, A.M. Dalsky. - M .: Mashinostroenie, 2002 .-- 306 p.

5. Information support of the life cycle of mechanical engineering products: principles, systems and technologies CALS / IPI [Text]: a textbook for students. higher. study. institutions / A.N. Kovshov [and others]. - M .: Publishing Center "Academy", 2007. - 304s.

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When developing a CAD system, the following stages are performed.

Pre-design studies are carried out to survey the organization for its readiness to automate the design process. The result should be an answer to the question: is the operation of CAD in this organization rational for the current period or is it necessary to carry out a complex of preparatory work?

Terms of Reference (TOR) is the initial document for creating a CAD, which should contain the most complete source data and requirements. This document is developed by the organization - the main developer of the system. The terms of reference should contain the following main sections:

1. "Name and scope" - the full name of the system and a brief description of the scope of its application;

2. "Basis for creation" - the name of the directive documents on the basis of which the CAD is created;

3. "Characteristics of the design object" - information about the purpose, composition, conditions of use of the design object;

4. "Purpose and purpose "- the purpose of creating a CAD system, its purpose and performance criterion;

5. "Characteristics of the design process" - a general description of the design process; requirements for input and output data, as well as requirements for the separation of design procedures (operations) performed using manual and computer-aided design;

6. "Requirements for CAD" - requirements for CAD in general and for the composition of £ £ subsystems, for the use of previously created CAD subsystems and components in CAD, etc .;

7. "Technical and economic indicators" - the cost of creating CAD, the peaks of savings and the expected efficiency from the application

Technical proposal, conceptual and technical design are the stages of selection and justification of options for making final decisions. At these stages, the following main work is performed:

Reveal the design process (its algorithm), where
basic technical solutions;

· Develop a CAD structure and its relationship with other systems, where the composition of design procedures and operations on subsystems is determined, the composition of subsystems and the relationship between them are specified; develop a scheme for the functioning of CAD;

When making decisions on mathematical, linguistic, technical, informational and CAD software in general
and subsystems are determined: the composition of methods, mathematical models for design operations and procedures; composition of design languages; composition of information, volume, methods of its organization and types of machine information carriers; composition of general and special software; composition

technical means (computers, peripheral devices and other computing control systems), calculate the technical and economic ate CAD.

When creating CAD, the stages of technical proposal and sketch, design are not mandatory, and the work included in them can rise at a subsequent stage.

Working design is the stage of registration of all the documentation necessary for the creation and operation of a CAD system.

The CAD components are then fabricated (received) and debugged. They carry out installation, commissioning and testing of a set of technical means of design automation and prepare the organization for putting into operation CAD.

Analysis of the functionality of CAD TP used for automated design of TP

Analysis of Mathematical Methods for Making Technological Decisions in the Context of Multi-Criteria Choice

The purpose and objectives of the thesis

Labor protection rules in logging woodworking industries and during forestry work

Rules for labor protection in logging woodworking industries and during forestry operations (1)