Question No. 1. Review of modern computer-aided design (CAD) systems

Computer-aided design system - automated system, which implements information technology for performing design functions, is an organizational and technical system designed to automate the design process, consisting of personnel and a set of technical, software and other means of automating its activities. The abbreviation CAD is also widely used to denote such systems.

Creation goals and objectives

As part of the life cycle of industrial products, CAD solves problems of automation of work at the stages of design and pre-production.

The main goal of creating CAD is to increase the efficiency of engineers, including:

reducing the complexity of design and planning;

reduction of design time;

reducing design and manufacturing costs, reducing operating costs;

improving the quality and technical and economic level of design results;

reducing costs for full-scale modeling and testing.

Achieving these goals is ensured by:

automation of documentation;

information support and automation of the decision-making process;

use of parallel design technologies;

unification of design solutions and design processes;

reuse of design solutions, data and developments;

strategic design;

replacing full-scale testing and prototyping with mathematical modeling;

improving the quality of design management;

application of variant design and optimization methods.

CAD Review

Traditionally, CAD products for mechanical engineering are divided into three classes: heavy, medium and light. This classification has developed historically, and although there has long been talk that the lines between classes are about to be erased, they remain, since the systems still differ in both price and functionality.

As a result, there are now several powerful systems in this area, the kind of “oligarchs” of the CAD world, steadily developing middle-class products and received mass distribution inexpensive “light” programs. There is also a so-called “non-class stratum of society”, the role of which is played by various specialized solutions.

CAD classes. Heavy CAD

Computer technology is not intended to automate traditionally existing technological links (since this usually does not give any effect, with the exception of some changes in working conditions), but to fundamentally change the very technology of design and production of products. Only in this case can we expect a significant reduction in the time required to create products, reduce costs over the entire life cycle of the product, and improve the quality of products.

First of all, in relation to the creation of complex mechanical engineering products, the basis of the organization computer technology lies in the creation of a complete electronic model of the product, since it is the creation of three-dimensional electronic models that are adequate to the actually designed product that opens up enormous opportunities for creating higher quality products (especially complex, knowledge-intensive products) and in a shorter time.

Ideally, in the process of designing and manufacturing complex and multi-component products, everyone involved in the design should, working simultaneously and observing each other’s work, immediately create electronic models of parts, assemblies, assemblies, systems and the entire product on computers.

At the same time, it is necessary to simultaneously solve problems of conceptual design, all kinds of engineering analysis, modeling situations, as well as product layout and the formation of external contours. Without waiting for the development of a new product to be completely completed, this information should be used for technological preparation of production and production as such. In addition, it is necessary to automatically manage all the created data of the electronic model (that is, the structure of the product), and the process of creating the product itself, and also be able to manage the structure of the process of creating the product.

To implement computer technology for design and production, computer-aided design, engineering analysis and technological preparation systems (CAD/CAE/CAM) of the highest level, as well as project management systems (PDM - Product Data Management), must be used.

Middle class CAD

In the world of CAD middle class arose later than the other two - in the early 90s. Previously, only expensive heavy systems had 3D solid modeling tools, and lightweight programs were used for 2D drawing. Medium CAD systems have taken an intermediate position between the heavy and light classes, inheriting from the former three-dimensional parametric capabilities, and from the latter - low price and focus on Windows platform. They revolutionized the world of CAD, paving the way for small design organizations to move from 2D to 3D design. An important role in the development of the middle class was played by two solid-state parametric modeling kernels ACIS and Parasolid, which appeared in the early 90s and are now used in many leading CAD systems. The geometric kernel serves to accurately mathematically represent the three-dimensional shape of a product and control this model. The geometric data obtained with its help is used by CAD, CAM and CAE systems to develop structural elements, assemblies and products. Currently, Parasolid is owned by EDS, and ACIS is owned by Dassault, which sell licenses for their use to anyone. There are many such people - these kernels form the basis of more than a hundred CAD systems, and the number of licenses sold has exceeded a million. The success is clear - after all, the use of a ready-made kernel relieves system developers from solving time-consuming solid modeling tasks and allows them to focus on the user interface and other functions. However, this does not mean that all middle-class CAD systems are built on the basis of these mechanisms. Many companies value independence and prefer to develop their own engines.

Analysts consider systems costing about 5-6 thousand dollars per workplace (prices in the USA) to be in the middle class. For comparison: for heavy CAD systems, a workplace costs about 20 thousand dollars, but Lately suppliers have released lighter versions of products that cost less.

According to the forecast of the analytical company Daratech, the growth of the middle class will continue, and it is expected that until 2008 the market will increase by 11% per year. The reason for such positive dynamics is the active influx of new users from both adjacent camps - heavy and light systems. Thus, according to analysts, there are now more and more manufacturers who are dissatisfied with the poor return on their investments in expensive products and are looking for cheaper options. On the other hand, globalization, increasing competition and the downturn in the global economy are forcing small and medium-sized enterprises to switch from 2D to 3D CAD to speed up the launch of new products and improve their quality. The transition is being driven by improved compatibility between 2D and 3D systems and increased productivity benefits of mid-range CAD software. Medium-sized CAD systems now have a wide range of potential consumers, and they, willingly or under market pressure, will be forced to implement them sooner or later. The expansion of the functionality of these products also plays into the hands of the “middle peasants”. As a result, enterprises that want a reliable 3D modeling tool, but can do without highly developed heavy CAD tools, now have additional options for selecting software. After all, suppliers previously claimed that the average CAD systems have 80% of the functions of heavy products, and their price is only 20% of the cost expensive systems. Now, according to analysts from Daratech, the “middle peasants” are approaching 90% in terms of capabilities and 50% in terms of cost.

Of course, even this 10% gap cannot be discounted. For example, enterprises in the automotive and aerospace industries are in dire need of advanced functionality found only in “heavyweights.” Therefore, the distinction between these two classes exists and will remain for the foreseeable future, since the developers of both systems are not sitting idly by, but will continue to improve your products.

SolidWorks has become a pioneer in the field of medium-sized CAD systems. In 1993, it introduced a product of the same name, which had a three-dimensional geometric core, which, according to the creators, was close in capabilities to solid-state modeling mechanisms for heavy systems, but was much cheaper. Soon the example of the pioneer was followed by Solid Edge, which released the CAD software of the same name, and then by Autodesk. She first developed the 3D Mechanical Desktop program based on 2D AutoCAD, and then created the new Inventor software. In addition to these systems, there are many other middle-class CAD systems on the market, for example think3, Cadkey, Alibre. There are also Russian developments among them. Thus, the ASCON company promotes the KOMPAS system based on its own geometric kernel, and the Top Systems company promotes the T-Flex program based on the Parasolid kernel owned by UGS. They have also gone through a long development path and acquired built-in tools for surface modeling, document management (PDM), technological preparation of production (CAM), etc., but at the same time they are significantly cheaper than their foreign counterparts and are initially focused on domestic standards and design techniques.

Light CAD

Programs in this category are used for two-dimensional drawing, so they are usually called an electronic drawing board. To date, they have added some 3D capabilities, but do not have the parametric modeling tools that heavy and medium CAD systems have.

The first drawing system, Sketchpad, was created back in the early 60s, and then many other products of this kind appeared, using advances in computer graphics. However, the real flourishing in this area came only in the 80s with the advent of personal computers. Following the decline in equipment costs, there was a collapse in prices for CAD systems.

The pioneer in this area was Autodesk, which in 1983 released a CAD system for PC called AutoCAD. The success was phenomenal - already in 1987, 100 thousand copies of AutoCAD were sold, and today this number exceeds four million. As a result, Autodesk was able to grab a fair share of the CAD market, displacing heavyweights from the 2D drawing software segment. The other players followed the example of the pioneer. So, in 1984, Bently introduced the Microstation program, which became the main competitor to AutoCAD. In addition to them, there are now many other “light” CAD systems, including DataCAD of the same company, TurboCAD from IMSI, SurfCAM from Surfware and others. These products are simpler and cheaper ($100 - $4,000) than heavy and medium-sized CAD systems, so they are in demand, despite the current economic downturn. As a result, “light” systems have become the most common design automation product, a kind of " workhorse"of the CAD world.

In addition to heavy, medium and light CAD, there are specialized CAD, industrial design, construction design(reinforced concrete), architectural design.

According to the unanimous opinion of analysts, the global CAD market has reached maturity. It developed and grew rapidly during the last decade of the last century. But by 2000, all the businesses that needed CAD software had acquired them, and it became difficult to find new users. And when the economic recession began in the West, the growth of the CAD market slowed down: according to the analytical company Daratech, in 1999, sales of CAD/CAM/CAE systems grew by 11.1% over the year, in 2000 - by 4.7% , in 2001 - by 3.5%, and in 2002 - by 1.3%. At the same time, the growth in turnover of leading CAD suppliers stopped. Daratech estimates that in 2002 the CAD market was worth $6.2 billion (user spending on software and services); in 2003, sales decreased by 4.5%.

So, at the turn of the century, a turning point came for the CAD market. In such a situation, companies usually merge and search for new directions for growth. An example is the purchase by EDS in 2001 of two well-known developers of heavy CAD systems - Unigraphics and SDRC. This deal created a real sensation in the CAD segment. However, now the success of the purchase is in doubt, since EDS is going to sell the UGS PLM division, formed by the merger of Unigraphics and SDRC. As for the search for new directions, leading suppliers are now actively promoting the concept of PLM (Product Lifecycle Management), which implies managing information about a product throughout its entire life cycle. The implementation of PLM promises many benefits for enterprises, but entails costs for the purchase of additional software (for example, engineering data management systems - PDM) and the reorganization of project processes.

Thus, the development of the CAD market follows two paths - evolutionary and revolutionary. At one time, the first CAD systems for PCs and middle-class systems produced a revolutionary revolution. Now the market is developing evolutionarily: the functionality of products is expanding, productivity is improving, and ease of use. But perhaps another revolution awaits us soon. Analysts at Cambashi believe this will happen when CAD vendors begin to use standard SQL-type databases to store engineering data (drawings, 3D models, bill of materials, etc.) instead of file structures. As a result, engineering information will become structured, and it will be much easier to manage than it is now.

Behind last years A real breakthrough was noticed in the design. Drawings and models migrated to virtual space, the data processing process noticeably accelerated, and a large number of new developments in the CAD systems market. They can all be divided into two large groups – foreign and domestic.

Foreign developments

Abroad, automatic design systems began to be used much earlier. A classification of CAD systems has also been developed here - for mechanical engineering, electrical power engineering, construction, etc. The following companies are considered trendsetters:

• Autodesk. A recognized global leader providing the best products. The company enjoyed success after its release AutoCAD solutions. For Russian consumers it became a godsend. Popular products for 2D design are offered by the POINT company - https://www.pointcad.ru/product#prod_2d.
• Unigraphics Solutions. The company gained publicity after concluding a contract with General Motors. The developers wrote almost all reviews of CAD systems with an emphasis on the automotive giant, so the direction of support is very specific.

• IMB ETS. The success is due to the controlled French company Dassault, which produces SolidWorks, CATIA, Deneb, MicroCADAM. There are solutions for almost all areas of industry.

• PTC. The main system is Pro/Engineer. Recently it has undergone many updates, and therefore deserves attention. Eat special package for shipbuilding corporations.

Review of domestically produced CAD systems

On Russian market There are also worthy players. Among them:

• ASCON. The popularity of COMPASS is growing at a noticeable pace. And all because the system is aimed primarily at domestic developers.

• Intermech. With its product Cadmech, the Minsk-based company is gradually gaining momentum. One of the advantages is a well-developed system for filling out documentation.

• Top Systems. The Moscow developer, who gave us T-FLEX CAD, has long since crossed the borders of Russia and began to spread in Europe.

Most Russian manufacturers work with AutoCAD, KOMPAS and SolidWorks systems. Let's look at them in more detail.

AutoCAD

The undisputed leader. For many, AutoCAD is the standard. Indeed, Autodesk software has a number of advantages:

• Rich set of functions. Most of the newest developments appear here first.

• Technical support. Current reviews of the CAD system and its capabilities are always publicly available.

• Updates and extensions. The product is constantly being developed and improved.

• Low requirements. One of the key factors. AutoCAD does not require overly powerful computers.

COMPASS

Not a single review of CAD/CAM systems in Russia is complete without mentioning KOMPAS. And there are several reasons for this:

• Focus on the domestic market. The program was originally developed in Russian, all instructions are readable.

• GOST Library. An undeniable plus. Designing with a ready-made GOST library is much more convenient and profitable.

• Version compatibility. One of the problems with foreign systems is that drawings created in older versions will most likely not open in new ones. Everything here is much simpler and friendlier.

SolidWorks

A system that is less popular than the previous ones. This is mainly due to the high performance requirements of the computer. However, SolidWorks has an intuitive interface and some features not available in other products.

The choice in favor of one or another software package is made on the basis of thoughtful analysis. AutoCAD can solve most problems, but sometimes specific functions and targeting a specific market are required. In some cases, the cost and demands of the product, its complexity and the availability of qualified specialists come to the fore.

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Introduction

Fierce competition has long reigned in industrial production. To survive in these difficult conditions, enterprises have to produce new products as quickly as possible, reduce their costs and improve quality. In this they are helped by modern computer-aided design (CAD) systems, which make it possible to facilitate the entire product development cycle - from developing a concept to creating a prototype and launching it into production. This significantly speeds up the process of creating new products without compromising quality. Therefore, now not a single design or industrial enterprise can do without CAD. And although these systems account for only about 3% of the software market, they play a very important role because they help create products without which it is impossible to imagine our daily lives: cars, airplanes, household appliances, industrial equipment and, therefore, are one of the driving forces forces of modern industry and the global economy.

The progress of science and technology, the need for new industrial products determine the need to carry out large-scale design work.

The design of machines and machine systems is a multi-step dynamic process. This process is creative, multifaceted and quite labor-intensive. As a rule, the design of machines, including hoisting and transport, construction and road machinery and equipment, is carried out by a large team of various specialists using numerous calculation, experimental, heuristic methods and techniques.

The requirements for the quality of projects and the timing of their implementation are becoming increasingly stringent as the complexity of the designed objects increases and the importance of the functions they perform increases. It is impossible to satisfy these requirements by simply increasing the number of designers, since the possibility of parallel implementation of design work is limited, and the number of engineering and technical workers in the country's design organizations cannot be significantly increased. The problem can be solved based on design automation - widespread use computer technology.

The goal of design automation is to improve quality, reduce material costs, reduce design time and eliminate the trend towards an increase in the number of engineering and technical workers involved in design, increasing their labor productivity.

CAD is an organizational and technical system consisting of a set of design automation tools, interconnected with the departments of the design organization and performing computer-aided design.

1 . General description of computer-aided design systems,their purposes and areas of application

1.1 General description of computer-aided design systems

CAD is an organizational and technical system that is part of the structure of a design organization and carries out design using a set of computer-aided design tools (CAD).

The interaction of departments of a design organization with a set of design automation tools is regulated by organizational support.

The main function of CAD is to perform computer-aided design at all or individual stages of designing objects and their components.

When creating CAD systems and their components, you should be guided by the following basic principles:

System unity;

Compatibility;

Typing;

Development.

The principle of system unity should ensure the integrity of the system and the systemic coherence of the design of individual elements and the entire design object as a whole (hierarchical design).

The principle of compatibility should ensure the joint functioning of the CAD components and maintain an open system as a whole.

The principle of typification is to focus on the primary creation and use of standard and unified CAD elements. Elements that have the prospect of repeated use are subject to typification. Standard and standardized elements are periodically examined for compliance with modern CAD requirements and modified as necessary.

The creation of a CAD system taking into account the principle of typing should include:

Development of a basic version of the KSAP and (or) its components;

Creation of a modification of the CSAP and (or) its components based on the basic version.

The development principle should ensure the replenishment, improvement and updating of CAD components, as well as interaction and expansion of relationships with automated systems various levels and functional purpose.

Work on the development of CAD and modernization of CAD components is carried out according to the technical specifications.

As a finished product, CAD is a combination of the following components:

· technical means providing automated receipt of design solutions;

· programs that control the operation of technical means and carry out design procedures;

· data necessary for program execution;

· documentation containing all the necessary information to perform computer-aided design using this CAD system.

To implement user tasks, software tools are required - precise and detailed instructions containing a sequence of actions for processing information. The computer itself does not have knowledge in any field of its application; all this knowledge is concentrated in the programs executed on the computer. CAD software includes a set of programs for various purposes that ensure the functioning of a computer system and the solution of computer-aided design problems.

When structuring software, the concepts of software systems, software systems, complexes and components are used. An application software package is a set of programs united by a common application, i.e. the possibility of joint execution or focus on a specific class of tasks. A complex, as defined in the Unified System of Program Documentation (USPD), is a complex program that can be divided into component parts. Components are components of programs that have their own functional purpose. The concept of “complex - component” is similar to the concept of “system - element” in the block-hierarchical design of complex systems, therefore, on each hierarchical level software design, these concepts are filled with their specific content. Thus, the ES OS operating system is a complex, and the FORTRAN compiler is its component. At the compiler design level, it is considered as a complex, and the parser and code generator are its components.

The constituent structural parts of CAD, rigidly connected with the organizational structure of the design organization, are subsystems in which, with the help of specialized complexes of tools, a functionally complete sequence of CAD tasks is solved.

Based on their purpose, subsystems are divided into design and maintenance.

Designing subsystems. They are object-oriented and implement a certain stage (stage) of design or a group of directly related design tasks.

Examples of design subsystems: preliminary design of products, design of body parts, design of technological processes of machining.

Servicing subsystems. Such subsystems have a system-wide application and provide support for the functioning of design subsystems, as well as the design, transmission and output of the results obtained in them.

Examples of service subsystems: automated data bank, documentation subsystems, graphical input-output subsystem.

The formation and use of models of a design object in applied problems is carried out by a set of computer-aided design tools (CAD) of a system (or subsystem).

The structural parts of the KSAP system are various sets of tools, as well as organizational support components.

Complexes of means are classified as industrial products to be manufactured, replicated and used as part of CAD, and are documented as specified products.

Complexes of tools are divided into complexes of tools of one type of support (technical, software, information) and combined ones.

Complexes of means of one type of support contain components of one type of support; complexes of combined means - a set of components of different types of support.

Combined KSAP related to products for industrial and technical purposes are divided into:

· program and methodological (PMK);

· software and technical (PTK).

A software and methodological complex is an interconnected set of software, information and methodological support components (including mathematical and linguistic support components) necessary to obtain a complete design solution for a design object (one or more of its parts or the object as a whole) or to perform unified procedures.

Depending on the purpose, PMCs are divided into system-wide and basic.

System-wide PMCs are aimed at design objects and, together with computer operating systems, are the operating environment in which basic complexes operate.

Basic PMCs can be problem-oriented and object-oriented, depending on whether they implement design procedures that are unified or specific to a certain class of objects.

Problem-oriented PMCs may include software designed for automated ordering of source data, requirements and restrictions for the design object as a whole or for assembly units; selection of the physical principle of operation of the design object; choice technical solutions and structure of the design object; assessment of quality indicators (manufacturability) of structures, design of routes for processing parts.

Object-oriented PMCs reflect the features of design objects as a total subject area. Such PMCs, for example, include PMCs that support automated design of assembly units; design of parts based on standard or borrowed solutions; parts based on their synthesis from form elements; technological processes by types of parts processing, etc.

The software and hardware complex is an interconnected set of hardware components.

Depending on the purpose of the hardware and software systems, they are distinguished: automated workstations (AWS); central computing complexes (CCCs).

Complexes of tools can combine their computing and information resources, forming local computer networks subsystems or systems as a whole.

The structural parts of complexes of tools are components of the following types of support: software, information, methodological, mathematical, linguistic and technical.

Components of support types perform a given function and represent the smallest (indivisible) independently developed (or purchased) CAD element (for example, a program, instructions, display, etc.). The effective functioning of CSAP and the interaction of structural parts of CAD at all levels should be achieved by focusing on standard interfaces and communication protocols that ensure the interaction of complexes of tools.

The effective functioning of the KSAP should be achieved through the mutually agreed development (coordination with purchased ones) of the components included in the complexes of funds.

KSAP of serving subsystems, as well as individual hardware and control systems of these subsystems can be used in the operation of all subsystems.

System-wide PMCs include software, information, methodological and other types of support. They are designed to perform unified procedures for managing, monitoring, scheduling the computing process, distributing CAD resources and implementing other functions that are common to subsystems or CAD systems as a whole.

Examples of system-wide PMCs: monitor systems, database management systems, information retrieval systems, computer graphics tools, dialogue mode support subsystem, etc.

Monitor systems for controlling the functioning of technical means in CAD. (Monitor is a control program).

The main functions of monitoring systems are: generation of tasks with control of a package of tasks, required and available resources, access rights to the database with establishment of priority and queue number; processing directives of task and task management languages, as well as responding to interruptions with interception of control, analysis of causes and their interpretation in terms understandable to the designer; servicing task flows with the organization of dialog and interactive graphic support in conditions of parallel operation of subsystems; design management in automatic modes with analysis of the quality of execution of project operations, checking the criteria for repeating a stage or continuing a route, choosing alternative options route; maintaining and optimizing system operation statistics; distribution of CAD resources taking into account the priorities of tasks, tasks and subsystems, planned tasks and current instructions and requests; protection of resources and data from unauthorized access and unintended impacts.

Information retrieval systems (IRS) in CAD perform such functions as filling the information fund (info library) with information; arithmetic processing of digital data and lexical processing of texts; processing information requests in order to find the required information; processing of output data and generation of output documents. The peculiarities of IPS are that queries to them are generated not programmatically, but directly by users, and not in a formal language, understandable to the monitor, and in natural language in the form of a sequence of keywords - descriptors. The list of descriptors contained in all descriptions accepted for storage constitutes a dictionary of descriptors, or thesaurus, and is intended for the formation of search instructions.

There are also more complex IPAs compared to descriptor ones. An important role in them is played by the information retrieval language, which takes into account the semantic relationships between information objects. This allows you to reduce the number of incorrectly recognized language constructs, and process requests based on various criteria of semantic correspondence.

Database management system (DBMS) is a software and methodological complex for ensuring work with an information base organized in the form of a data structure.

Data banks are the highest form of information organization in large CAD systems. They are problem-oriented information and reference systems that provide input necessary information, independent of the specific tasks of maintaining and storing information arrays and issuing the necessary information at the request of users or programs. Data banks use factual information.

The DBMS performs the following main functions: defining databases, i.e. describing the conceptual, external and internal levels of schemas; writing data to the database; organizing storage by changing, adding, and reorganizing data; providing access to data (search and retrieval).

To define data and access it, the DBMS has language tools. Thus, the definition of data, consisting of a description of its structures, is provided using a data definition language. Data access functions are implemented using a data manipulation language and a query language. Based on the type of structures supported, there are: the following types DBMS:

hierarchical

· network

relational

Software and methodological complexes of computer graphics ensure interaction between the user and the computer when exchanging graphic information, solving geometric problems, forming images and automatically producing graphic information. Graphical interaction between the user and the computer (the so-called graphical access method) is based on input-output routines, which ensure the receipt and processing of commands from the input-output device and the issuance of control actions on these devices. The solution of geometric problems (geometric modeling) comes down to the transformation of graphic information, which represents the execution in one or another sequence of elementary graphic operations such as shift, rotation, scaling, etc. For geometric modeling, the PMC is used, in which, in addition to individual elementary graphic operations, graphic transformations of three-dimensional images, procedures for constructing projections, sections, etc. can be implemented. The graphic transformation software usually provides tools for generating some frequently used images, managing a graphic database, and debugging graphic subroutines.

The dialog mode is provided by software and methodological complexes that input, control, edit, convert and output graphic and/or symbolic information. Conversational remote entry of tasks provides entry and editing of tasks via communication channels, execution of tasks in batch mode and output of results via communication lines to remote terminals. CAD systems can use both general-purpose and specialized interactive PMCs. It is advisable to use general-purpose PMCs at the initial stages of creating and operating CAD systems to test and test design methodology, data processing technology and application programs. In the future, it is possible to modify the PMC taking into account the specific requirements for organizing dialogue in CAD. In this case, it is necessary to take into account the presence of an interactive or batch mode for processing requests; orientation of the system towards a non-programmer user; the ability to expand the system by including interactive application programs in high-level languages; the ability to control dialogue using “menus” and directives, the desirability of communicating in native language and so on.

Examples of PMCs for providing interactive modes: a system for interactive control of task input, a time-sharing mode system, etc.

The functioning of CAD is possible only with the presence and interaction of the following tools:

- software;

- information support;

- methodological support;

- linguistic support;

- technical support;

- organizational support.

Now let's briefly understand the purpose of each component of CAD tools

CAD software is a collection of all programs and operational documentation for them necessary to perform computer-aided design. Software is divided into general system and special (application) software. System-wide software is intended for organizing the functioning of technical means, i.e., for planning and managing the computing process, distributing available resources, and is represented by various operating systems. Special software implements mathematical support for the direct implementation of design procedures.

CAD information support. The basis is the data that designers use during the design process directly to develop design solutions. This data can be presented in the form of certain documents on various media containing reference information about materials, parameters of elements, information about the state of current developments in the form of intermediate and final design solutions.

Methodical CAD support. The methodological support of CAD is understood as the documents included in its composition that regulate the procedure for its operation. Moreover, documents related to the process of creating CAD are not included in the methodological support. So, basically, methodological support documents are of an instructive nature, and their development is a creative process.

CAD software. The basis is the algorithms by which CAD software is developed. Among the various elements of mathematical software, there are invariant elements - principles for constructing functional models, methods for numerical solution of algebraic and differential equations, formulation of extreme problems, search for extremum. The development of software is the most difficult stage of creating a CAD system, on which the productivity and efficiency of the CAD system as a whole largely depends.

Linguistic CAD support. The basis is made up of special language tools (design languages) intended to describe computer-aided design procedures and design solutions. The main part of linguistic support is the languages ​​of communication between humans and computers.

CAD technical support. This is the creation and use of computers, plotters, office equipment and all kinds of technical devices, facilitating the process of computer-aided design.

Organizational securityCAD This paragraph prescribes staffing CAD departments with professionally competent specialists who have the skills and knowledge to work with the CAD components listed above. The efficiency and quality of the entire CAD complex (maybe even the entire production) will depend on their work.

1.2 Purposes and areas of application of CAD

In Russian manufacturing, the concept of computer-aided design (CAD) system usually includes CAD, CAE and CAM, although foreign designers associate CAD only with CAD.

Depending on the CAD design object, it is customary to de-

pour into at least two main types:

CAD (Computer-Aided Design). Here Computer - computer, Aided - with the help, Design - project, to design. Thus, the term CAD can be translated as “computer-assisted design.” These systems perform volumetric and plane geometric modeling, engineering calculations and analysis, evaluation of design solutions, and production of drawings. In a more strict formulation, CAD is a software package intended for the design (development) of production (or construction) facilities, as well as the preparation of design and/or technological documentation. Modern CAD systems are used in conjunction with CAE automation systems for engineering calculations and analysis, or contain integrated automation tools for engineering calculations and analysis. Data from the CAD system is transferred to a CAM system for the automated development of control programs for CNC or GAPS (Flexible Automated Manufacturing Systems) equipment. Working with CAD usually involves creating a geometric model of a product (two-dimensional or three-dimensional, solid), generating design documentation (product drawings, specifications, etc.) based on this model, and its subsequent maintenance.

It should be noted that the Russian term "CAD" in relation to industrial systems has a broader interpretation than CAD - it includes CAD, CAM and CAE.

CAD manufacturing technology. In the countries of the former Soviet Union These systems are usually called CAD TP or AS TP. In foreign literature they are called CAPP (Computer Automated Process Planning). Here Automated - automatic, Process - process, Planning - plan, planning, drawing up a plan. With the help of these systems, technological processes are developed and formalized in the form of route, operational, route-operational maps, technological equipment is designed, and control programs (CP) are developed for CNC machines.

A more specific description of the processing technology on CNC equipment (in the form of control program frames) is generated by an automated production equipment control system (APS), which in foreign literature is usually called CAM (Computer- Aided Manufacturing) . Here Manufacturing is production, manufacturing. By technical means Implementing this system can be CNC systems of machine tools, computers that control automated machine tools. In some sources, the term CAM refers to the preparation of the technological process for the production of products, focused on the use of computer technology, and including not only the process of computerized production preparation itself, but also software and computing systems used by design technologists. In fact, technological preparation comes down to automating the development of control programs for CNC equipment (2-axis laser machines), (3- and 5-axis CNC milling machines; lathes; machining centers; automatic longitudinal turning and turning-milling machines). As a rule, most software and computing systems combine solving CAD/CAM, CAE/CAM, CAD/CAE/CAM problems.

The research stage of design is sometimes separated into an independent automated scientific research system (ASRS) or, using foreign terminology, an automated engineering system - CAE (Computer Aided Engineering). One example of such a system is the so-called “inventing machine,” which supports the designer’s process of making new non-standard solutions, sometimes at the level of inventions. In a narrower sense, CAE is a general name for programs or software packages designed for engineering calculations, analysis and simulation of physical processes. The calculation part of the packages is most often based on numerical methods for solving differential equations (finite element method, finite volume method, finite difference method, etc.). Modern automation systems for engineering calculations (CAE) are used in conjunction with CAD systems (often integrated into them, in which case hybrid CAD/CAE systems are obtained). CAE systems are a variety of software products that allow you to evaluate how a computer model of a product will behave under real operating conditions. They allow you to check the performance of the product without spending a lot of time and money.

In addition, they distinguish: the production planning and management system PPS (Productions plans system), which corresponds to the domestic term automated control system (automated production control system). CAQ (Computer Aided Quality Control) is an automated quality management system. PDM (Product Data Management) is an automated production information management system. Analogue system electronic document management. CAD/CAM/CAE/PDM - complex system computer-aided design and production. CIM (Computer Integrated Manufacturing) is an integrated production system.

2 . Application of computer-aided design systemsin mechanical engineering

Directly in mechanical engineering, specialized packages and various add-ons of more general and widespread design systems, such as Autodesk AutoCAD, ZwCAD, BricsCAD, Cosmos, SolidWorks and others, are used. Let's take a closer look at some of the systems.

Traditionally, CAD products for mechanical engineering are divided into three classes: heavy, medium and light. This classification has developed historically, and although there has long been talk that the lines between classes are about to be erased, they remain, since the systems still differ in both price and functionality.

As a result, there are now several powerful systems in this area, the kind of “oligarchs” of the CAD world, steadily developing middle-class products and inexpensive “lightweight” programs that have become widespread. There is also a so-called “non-class stratum of society”, the role of which is played by various specialized solutions.

2.1 Heavy CAD

Computer technology is designed do not automate tradAndnationally existing technological links(since this usually does not have any effect, except for some change in working conditions), and in principlehchange the very technology of design and production of products. Only in this case can we expect a significant reduction in the time required to create products, reduce costs over the entire life cycle of the product, and improve the quality of products.

First of all, in relation to the creation of complex mechanical engineering products, the basis of the organization of computer technology is the creation of a complete electronic model of the product, since it is the creation of three-dimensional electronic models that are adequate to the actually designed product that opens up enormous opportunities for creating higher quality products (especially complex, knowledge-intensive products) and in a shorter time frame.

Ideally, in the process of designing and manufacturing complex and multi-component products, everyone involved in the design should, working simultaneously and observing each other’s work, immediately create electronic models of parts, assemblies, assemblies, systems and the entire product on computers.

At the same time, it is necessary to simultaneously solve problems of conceptual design, all kinds of engineering analysis, modeling situations, as well as product layout and the formation of external contours. Without waiting for the development of a new product to be completely completed, this information should be used for technological preparation of production and production as such. In addition, it is necessary to automatically manage all the created data of the electronic model (that is, the structure of the product), and the process of creating the product itself, and also be able to manage the structure of the process of creating the product.

To implement computer technology for design and production, computer-aided design, engineering analysis and technological preparation systems (CAD/CAE/CAM) of the highest level, as well as project management systems (PDM - Product Data Management), must be used.

What is a top-level CAD/CAE/CAM system? This is a system that, firstly, provides the entire product creation cycle from conceptual idea to implementation, and secondly (and this is the most important thing), creates a design and technological environment for the simultaneous work of all participants in the creation of a product with a single virtual electronic model of this products.

In the West, this organizational philosophy is denoted by the abbreviation CAPE (Concurrent Art-to-Product Environment), which can be translated as “A single environment for creating a product from idea to implementation.” Essentially, it is the extent to which the system implements the specified philosophy that determines the level of the system. Guided by this concept, you can dramatically shorten the product creation cycle, increase the technical level of projects, avoid inconsistencies and errors in the manufacture of equipment and the product itself due to the fact that such a case all data is interconnected and controlled.

Currently, there are only three high-end CAD systems left on the market - Unigraphics NX from EDS, CATIA from the French company Dassault Systemes (which is promoting it together with IBM) and Pro/Engineer from RTS (Parametric Technology Corp.). Previously, there were more powerful systems, but after a series of mergers and acquisitions of companies, the number of packages decreased.

The companies mentioned are leaders in the field of CAD, and their products occupy the lion's share of the market in monetary terms. The main feature of “heavy” CAD systems is their extensive functionality, high performance and job stability are all the result of long-term development. However, these systems are not young - CATIA appeared in 1981, Pro/Engineer - in 1988, and Unigraphics NX, although released in 2002, is the result of the merger of two very venerable systems - Unigraphics and I -Deas received by EDS as a result of the acquisition of Unigraphics and SDRC. All of these programs include three-dimensional solid and surface modeling tools, as well as structural analysis and pre-production modules, i.e. they are integrated CAD/CAM/CAE packages. In addition, all three vendors offer engineering data management (PDM) systems for their CAD systems, allowing you to manage all design documentation and provide additional data exported from other corporate systems, from reference books and regulatory sources.

Despite the fact that heavy systems are much more expensive than their “lighter” counterparts (tens of thousands of dollars per workstation), the cost of purchasing them pays off, especially when we're talking about about complex production, for example mechanical engineering, engine building, aviation and aerospace industries. However, there are not many large clients capable of paying millions of dollars for CAD. According to analysts, this market segment is already almost saturated and divided among the “whales” of the industry. Now manufacturers of design automation tools are pinning their hopes on small and medium-sized businesses, which are much more numerous than industrial giants. Middle and light class systems are designed for them.

2.2 Middle class CAD

In the world of CAD, the middle class emerged later than the other two - in the early 90s. Previously, only expensive heavy systems had 3D solid modeling tools, and lightweight programs were used for 2D drawing. Medium-sized CAD systems have taken an intermediate position between the heavy and light classes, inheriting three-dimensional parametric capabilities from the former, and low price and focus on the Windows platform from the latter. They revolutionized the world of CAD, paving the way for small design organizations to move from 2D to 3D design.

An important role in the development of the middle class was played by two solid-state parametric modeling kernels ACIS and Parasolid, which appeared in the early 90s and are now used in many leading CAD systems. The geometric kernel serves to accurately mathematically represent the three-dimensional shape of a product and control this model. The geometric data obtained with its help is used by CAD, CAM and CAE systems to develop structural elements, assemblies and products. Currently, Parasolid is owned by EDS, and ACIS is owned by Dassault, which sell licenses for their use to anyone. There are many such people - these kernels form the basis of more than a hundred CAD systems, and the number of licenses sold has exceeded a million. The success is clear - because using a ready-made kernel relieves system developers from solving time-consuming solid modeling tasks and allows them to focus on the user interface and other functions. However, this does not mean that all middle-class CAD systems are built on the basis of these mechanisms. Many companies value independence and prefer to develop their own engines.

Analysts consider systems costing about 5-6 thousand dollars per seat (prices in the USA) to be in the middle class. By comparison, heavy-duty CAD systems cost about $20,000 per seat, but recently vendors have released lightweight versions of products that cost less.

According to the forecast of the analytical company Daratech, the growth of the middle class will continue, and it is expected that until 2008 the market will increase by 11% per year. The reason for such positive dynamics is the active influx of new users from both adjacent camps - heavy and light systems. Thus, according to analysts, there are now more and more manufacturers who are dissatisfied with the poor return on their investments in expensive products and are looking for cheaper options. On the other hand, globalization, increasing competition and the downturn in the global economy are forcing small and medium-sized enterprises to switch from 2D to 3D CAD to speed up the launch of new products and improve their quality. The transition is being driven by improved compatibility between 2D and 3D systems and increased productivity benefits of mid-range CAD software.

Medium-sized CAD systems now have a wide range of potential consumers, and they, willingly or under market pressure, will be forced to implement them sooner or later. The expansion of the functionality of these products also plays into the hands of the “middle peasants”. As a result, businesses that want a reliable 3D modeling tool but can do without sophisticated heavy-duty CAD tools now have additional software options. After all, suppliers used to claim that average CAD systems had 80% of the functions of heavy-duty products, and their price was only 20% of the cost of expensive systems. Now, according to analysts from Daratech, the “middle peasants” are approaching 90% in terms of capabilities, and in terms of cost – 50%. Of course, even this 10% gap cannot be discounted. For example, the automotive and aerospace industries desperately need cutting-edge functionality found only in the heavyweights. Therefore, the difference between these two classes exists and will remain for the foreseeable future, since the developers of both systems are not sitting idly by, but will continue to improve their products.

SolidWorks has become a pioneer in the field of medium-sized CAD systems. In 1993, it introduced a product of the same name, which had a three-dimensional geometric core, which, according to the creators, was close in capabilities to solid-state modeling mechanisms for heavy systems, but was much cheaper. Soon the example of the pioneer was followed by Solid Edge, which released the CAD software of the same name, and then by Autodesk. She first developed the 3D Mechanical Desktop program based on 2D AutoCAD, and then created the new Inventor software. In addition to these systems, there are many other middle-class CAD systems on the market, for example think3, Cadkey, Alibre. There are also Russian developments among them. Thus, the ASCON company promotes the KOMPAS system based on its own geometric kernel, and the Top Systems company promotes the T-Flex program based on the Parasolid kernel owned by UGS. They have also gone through a long development path and acquired built-in tools for surface modeling, document management (PDM), technological preparation of production (CAM), etc., but at the same time they are significantly cheaper than their foreign counterparts and are initially focused on domestic standards and design techniques.

2.3 Lightweight CAD systems

Programs in this category are used for two-dimensional drawing, so they are usually called an electronic drawing board. To date, they have added some 3D capabilities, but do not have the parametric modeling tools that heavy and medium CAD systems have.

The first drawing system, Sketchpad, was created back in the early 60s, and then many other products of this kind appeared, using advances in computer graphics. However, the real flourishing in this area came only in the 80s with the advent of personal computers. Following the decline in equipment costs, there was a collapse in prices for CAD systems.

The pioneer in this area was Autodesk, which in 1983 released a CAD software for PC called AutoCAD. The success was phenomenal - already in 1987, 100 thousand copies of AutoCAD were sold, and today this number exceeds four million. As a result, Autodesk was able to grab a fair share of the CAD market, displacing heavyweights from the 2D drawing software segment. The other players followed the example of the pioneer. So, in 1984, Bently introduced the Microstation program, which became the main competitor of AutoCAD. In addition to them, there are now many other “light” CAD systems, including DataCAD of the same company, TurboCAD from IMSI, SurfCAM from Surfware and others. These products are simpler and cheaper ($100 - $4,000) than heavy and medium-sized CAD systems, so they are in demand, despite the current economic downturn. As a result, “light” systems have become the most common design automation product, a kind of “workhorse” of the CAD world.

3 . Functionality of the software product "nanoCAD»

3.1 Basicfeatures of the product "nanoCAD"

nanoCAD -- basic system computer-aided design and drawing (CAD platform). Developed by Nanosoft, Russia. In Russia and the CIS countries it is distributed under the "freeware" scheme. It has an AutoCAD-like interface and directly supports the DWG format (using Teigha™ libraries, developed by Open Design Alliance). Based on a free platform nanoCAD A number of paid applications are being created to perform various highly specialized project tasks.

The advantages of the nanoCAD product include:

· Zero price: The software is distributed free of charge and is available for commercial use by both individuals and project organizations.

· Familiar interface: principles of working with nanoCAD are similar to the principles of work in AutoCAD, which allows the user to change platforms without major retraining.

· Direct supportDWG: drawings developed in nanoCAD can be opened in the AutoCAD environment without additional transformations and vice versa, drawings developed in the AutoCAD environment are opened in the environment nanoCAD.

· Open API: you can develop for nanoCAD native applications in C++ or .NET languages.

The disadvantages of nanoCAD include:

· Lack of AutoLISP and VBA support: any applications and adaptation tools written in AutoLISP and VBA languages, in this moment do not work in the nanoCAD environment.

· Potential problems with DWG support: because nanoCAD supports the DWG format using Teigha™ libraries developed by the non-profit organization Open Design Alliance, there is a potential for loss of compatibility with the original Autodesk DWG format. Under the current conditions, this is unlikely: ODA libraries are used by about 750 organizations (ODA Members, including Adobe, Oracle, Bentley, Dassault Systіmes, Siemens, Graphisoft, Russian companies- Askon, Nanosoft, SiSoft, Infrasoft, etc.). At the moment, the bulk of drawings in DWG format processed fairly reliably, including visualization, editing and saving.

Product « nanoCAD"functionally occupies a niche between AutoCAD LT and the full version of AutoCAD. Developers nanoCAD They believe that not a single platform, being essentially an electronic drawing board, can be called CAD. Therefore, distributing the platform nanoCAD free of charge, Nanosoft offers users to use paid applications, running on both the AutoCAD platform and the nanoCAD.

3.2 Functionality

Interface nanoCAD latest versions is as close as possible to the interface of classic CAD systems: the main part of the window is occupied by working space, in which the drawing is directly developed, in the upper part there are menus and panels with navigation tools, in the lower part there is a command line. Commands and menus correspond to the interface organization AutoCAD versions 2000-2008.

Despite the visual similarity to AutoCAD (as well as programs based on the IntelliCAD kernel, which are copies of AutoCAD), the kernel nanoCAD is being developed by Russian developers independently. This leads to some differences in performance nanoCAD from working in the AutoCAD environment: so in nanoCAD many functions and technologies included in AutoCAD are missing (sheet set technology, working with dynamic blocks dynamic input information, etc.).

For now nanoCAD is positioned as a detailed 2D design (drawing) system and contains everything necessary tools basic design and allows:

· Create and edit various 2D and 3D vector primitives, single and multi-line texts, dimensions and other, more complex objects preparation of drawings in accordance with ESKD and SPDS standards.

· Perform simple and complex operations vector editing, such as move, rotate, split, extend, etc.;

· Use tools that increase editing accuracy: step, grid, snaps, object and polar tracking;

· Create and use any types of tables, carry out specification of drawing elements based on attribute data of blocks and design objects;

· Configure the working environment to prepare working documentation for different standards;

· Print ready-made technical documents using pre-defined settings;

· Conduct full work in 3D model space and 2D sheet space using viewports;

· View, create and edit surface 3D models, set custom coordinate system for editing and geometric binding to 3D objects;

· When designing, use any previously completed technical documentation, stored in in electronic format in various raster formats (scanned drawings, photographs) or as OLE objects (texts, tables);

· Exchange finished drawings with third parties and subcontractors using the common DWG format.

4 . Functionality of the software product « Pro\ ENGINEER»

computer-aided design system

4.1 Main features of the product "Pro\ ENGINEER»

Pro/ENGINEER is, first of all, a three-dimensional design system, both solid and surface, providing obvious advantages over the traditional two-dimensional design of the past:

clarity of presentation of the designed model - allows you to avoid mistakes associated with the fact that in two-dimensional design it is difficult for the designer to imagine a solid model, especially one with complex geometry;

operating geometry at the level of objects - engineering elements, which significantly simplifies and speeds up the design process. Core Pro/ENGINEER uses a technology unique in its capabilities - Proven Technology, based on boundary views. The main difference between Proven Technology and the well-known 3D design technologies ACIS, Parasolid, used in competing products (UNIGRAPHICS, I-DEAS, CADDS, EUCLID) is the strict requirements for the designed geometry (the geometry must be unambiguously determined). Such restrictions do not require designers to extra effort during design, but allow achieving full compliance of the geometry of the resulting part with the given dimensions, which is most critical in further work on the model (manufacturing of technological equipment, preparation of programs for processing on CNC machines, etc.).

The product design phase includes three-dimensional modeling, design optimization, preparation of working drawings and definition of manufacturing processes (design of programs for CNC machines). The effective combination of all these functions significantly reduces time to market. Main advantage Pro/ENGINEER before traditional design methods - support for parallel product development. This ensures that the product is released to the market faster than competitors, at a lower price and of higher quality.

4.2 Functionality

Software modules Pro/ENGINEER for solving design problems are intended for design engineers and provide them with a tool for creating models of both individual parts and complex assembly structures. It is a rigorous, logical, easy-to-use system that allows you to act intuitively and creatively. It allows you to design and manage large, complex assemblies consisting of a virtually unlimited number of components. Control over the intersection of individual parts and calculation of mass characteristics ensures correct assembly the first time. This significantly reduces design time and makes it easier to reuse standard, proven designs as the basis for new products.

Use in Pro/ENGINEER a unified information model of the product allows process engineers to begin developing equipment and control programs for CNC equipment without waiting for the final completion of the design stage. The designers have not yet finished working with the assembly, but technologists are already working on developing technical processes for manufacturing its constituent parts, correcting possible design errors if necessary. This significantly reduces the time and money spent on design and work, and allows optimal use of the collective experience of developers.

A package of software modules for technological preparation of production is intended for process engineers and allows them to solve problems of designing technological equipment (dies, molds), developing control programs for metal-cutting, CNC stamping equipment, as well as wire EDM equipment.

Conclusion

nanoCAD designed to prepare drawings in accordance with the requirements Unified system design documentation(ESKD). The program is convenient for designing systems of hydropneumatic elements, gears, shafts, as well as conducting engineering analysis, calculating dimensional chains and many other operations necessary for mechanical engineering design.

Pro/ ENGINEER- full-featured CAD for developing products of any complexity. With powerful automation capabilities across all mechanical engineering disciplines, Pro/ENGINEER is a globally recognized 3D solution for modeling and developing competitive commercial products. Integrated CAD/CAM/CAE solutions Pro/ENGINEER enable you to design faster than ever, maximizing new ideas and improved quality, ultimately leading to outstanding products.

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