Computer-Aided Design Systems


At the present stage of development of engineering and technology, both in our country and around the world, computer-aided design (CAD) systems are widely developed in various fields of science and technology: mechanical engineering, architecture, construction, clothing industry, etc.

The main goals of computer-aided design are to improve quality, reduce material costs, and reduce design time.

Computer-Aided Design Systems

CAD is an organizational and technical system based on the regular use of mathematical methods and computer hardware.

The activities of research institutes, design bureaus, and design organizations are associated with the development of new technologies, devices, instruments, and structures. The design is accompanied by the execution of a large amount of technical documentation: drawings, diagrams, plans.

Modern software and hardware of computer technology make it possible to move from traditional manual (routine) design methods to new information technologies for design using computers.

To facilitate the work of designers, designers, computer-aided design CAD (Computer A ided Design ) systems have been developed. These three letters are included in the names of many foreign programs designed for designing, drawing, three-dimensional modeling of three-dimensional objects and drawing up engineering documentation. For example, P-CAD, AVTOCAD, ARCHICAD.

With the help of CAD, they perform a full cycle of design and production: drawing up a technical assignment, developing an object, and preparing documentation. For this reason, the CAD/CAM (computer aided design/computer aided manufacturing) system is most often spoken of, a computer-aided design and manufacturing system that covers a wide range of tasks from initial design to the preparation of data necessary for actual production.

AM systems not only facilitate the process of creating and describing new objects, but also serve as a convenient reference book that allows users to accumulate and store information.

CAD at light industry enterprises

At many light industry enterprises, about 15 years ago, the first CAD patterns and pattern layouts appeared. These were very expensive systems of leading foreign companies in this field – Gerber (USA), Lectra (France), Investronica (Spain). Enterprises that have mastered computer technology quickly felt the benefits, and a return to traditional methods of work is no longer possible there.

The use of computer technology in the clothing industry can significantly improve the quality and reduce the development time for new products. Many technological processes are automated in the industry. Foreign systems of complex automation of enterprises (for example, Gerber (USA), Lectra (France), Investronika (Spain)), which are mainly used to automate the location of patterns in the flooring, cutting patterns and organizing production, have become widespread at large enterprises. Computer technology has long been used in many technological operations. However, the use of computer technology at all stages of the design of garments became possible only with the widespread introduction of personal computers close to the user.

For some time, domestic systems could not compete with foreign ones due to the lack of computer technology comparable in terms of capabilities and reliability. When modern personal computers and peripheral devices became widely available, domestic systems began to develop rapidly, such as Leko, Assol, Grazia, Abris, Comtens, etc.

Computer-aided design is one of the topical areas for improving the technological preparation of production, ensuring high quality and efficiency of design solutions. Application programs and systems designed to solve professional problems help a specialist to cope with a huge amount of information, store in a systematic way, quickly find, process and reuse the accumulated data, as well as create new information arrays based on them.

The experience of using application programs in the garment industry allows us to conclude that the most effective and convenient is the combination of several types of application programs within a single information environment. Obviously, for example, it is predominantly end-to-end product design, when the automated workstations (AWS) of the artist, designer, technologist and standardizer have the ability to access and use information generated at any stage of product development.

Currently, there are a large number of various AP systems on the market, differing in the volume and quality of the implementation of various stages of design and technological preparation for the production of clothing, reliability, productivity, the minimum set of equipment necessary for their operation, cost, ability to develop, compatibility with other systems.

Table Modern AP clothing systems

No. System Firm The country a brief description of
Leko Vilar Russia Used for designing clothes. 3D design system announced. System capabilities: – building patterns; – layout of patterns; – use of “substrate” patterns; – transfer of patterns to other CAD systems; – Digitization of patterns using a digital camera; – measurement of individual characteristics by digital photography. New models are offered on CD or sent by e-mail.
“Comtens” Comtens Ltd. Russia Structure of CAD: – administrator; – AB OVO – parametric design; – graphics editor; – working product; – layout; – track; – piece calculation; – rationing of raw materials; – technological sequence; – converter.
“Assol” Moscow Institute of Physics and Technology Russia Used for designing clothes. Includes the following subsystems: – design; – gradation; – layout; – photodigitizer; – piece calculation; – technologist; – technical drawing; – designer. It is possible to design hats, leather goods, bags, shoes, toys, covers, upholstered furniture, etc.
“Autocut” “Lakshmi” Belarus It is used for the design of garments and knitwear. Includes the following modules: – development of basic structures (BC) by calculation and analytical method; – creation of model structures (MC) in an interactive graphical mode; – development of BK and MK for all standard sizes by the method of simulation parametrization; – layout of patterns in interactive mode.
Julivi SAPRLEGPROM Ukraine CAD modules: – design of basic structures; – input of information from the digitizer; – design; – layout; – planning of pre-production; – output of information to the plotter, automated cutting complex; – 3D mannequin; – data converter.
“Grace” “Infocom” Ukraine Automated clothing design system, which includes the following subsystems: – artist; – constructor; – models and modeling; – layout and results; – technology; – dispatcher; – sales.
“STAPRIM” SPGUTD Russia The design of voluminous clothes is carried out and the development of details is obtained on its basis. The design of shoulder clothing in the system includes the following steps: – creation of a three-dimensional model of the human torso (dummy); – creation of a three-dimensional silhouette design of a clothing model; – development of model structures.
Accu Mark Gerber Technology USA Provides automation and reduction of data processing in preparation for nesting by entering individual client parameters.
Systems Lectra System France Systems for computer-aided design of products for the clothing, textile, footwear and furniture industries.
AGMS-3D Asahi Chemical Industry Japan It is applied to design of clothes both for individual tailoring, and for mass production.
PAD System PAD System Technologies Canada It is used for designing clothes (construction, gradation and layout of patterns). Having developed a model, the designer can get its three-dimensional image on a mannequin.
“Abris” “Abris” Russia It is used for designing clothes (construction, gradation, layout of patterns).

CAD in design

Advantages of CAD over manual design:

1. Speed (1 million operations per minute);

2. Large memory;

3. Ability to compare data in a wide range;

4. Improving the quality of design work;

5. Calculation accuracy up to 0.001 micron;

6. Increasing the culture of production;

7. Easy search for the necessary information.

Disadvantages of foreign CAD systems:

– Interface in a foreign language;

– Systems are usually closed for development;

– The systems are designed for the flawless operation of the electrical network;

– Dear tech. service;

– The cost is much higher than domestic ones.

Economic indicators of CAD implementation:

– Reducing the duration of primary development of structures by 3-4 times;

– Reducing the complexity of gradation by 3-5 times (or completely eliminated);

– Preparation of the model for production;

– Material savings – 2-3%;

– Reducing the cost of the drug industry by 80%;

– Increasing the productivity of the designer by 2-3 times;

– In terms of production, the cost of CAD pays off within 12 months.

Types of computer technologies for clothing design:

BC development
MK development
Development of primary patterns
Design verification
Gradation patterns
Pattern layout
Development of technical documentation
Development of new models by modification

– Manual execution method;

– Dialog execution method;

– Automatic

According to method I, the product design for the basic size-growth is developed manually, and preparation for launching into production is carried out using computer technology.

According to the II method, manual work is completely excluded, the entire process of design and preparation for production is carried out using computer technology in an interactive mode. According to the second method, CAD works: “Abris”, “Comtens”, “Slavyanka”, “Silhouette”, “Coral”, “SAPRO”, “SAPRLEGPROM”.

With method III, the system performs some of the stages automatically (without human intervention), the remaining stages are carried out in an interactive mode with the active participation of the designer. Work: “Avtokroy”, “Assol”, “Staprim”.

Method IV combines interactive and automatic modes, but they are implemented on the basis of rational computer technologies using improved design routes. Work: “Grace”, “Grafis”, “Leko”.

Types of CAD software

1. Technical support

2. Math

3. Software

4. Linguistic

5. Informational

6. Methodical

7. Organizational

Technical support includes:

1. Device for software data processing (processor)

2. Devices for preparing and entering data (keyboard, mouse, graphic tablet, light pen) – operator devices; peripheral – digitizer and scanner.

3. Data output devices – plotters (plotters), printers. Plotters are wide-format: pen and inkjet; “large printers”. For wide-format plotters, the width of the working area reaches 180 cm; for “large printers” – up to 1 meter.

4. A device for operational interaction with a computer – a monitor.

5. Communication devices (tables, adapters, modems).

Mathematical software is mathematical expressions, mathematical models that describe the processes being implemented.

CAD software – a list of commands written in a language accepted for programming.

CAD methodological support – instructions on the actions that designers must perform when designing.

Organizational support – order, staffing, mode of operation.

Linguistic support is programming languages:

– design languages that a person is able to understand;

– programming languages in which programmers work;

– languages of machine codes, understood by the computer itself.

Programming languages are high-level algorithmic languages for solving computational and logical problems.

Design languages are:

– menu command language;

– language of dialog boxes;

– a specialized programming language.

Information support of CAD is a set of initial data and means of managing initial data. DB – database; DBMS – database management tools. DB (dimensional characteristics, increments, etc.).

General CAD structure of clothes:

– Artist

– Constructor

– Layout

– Technologist

– Administrator

– Program of work with an individual consumer

– Program dispatcher, etc.

Subsystem “Artist”

Performs the following types of work:

– Model design sketch (via tablet, scanner (photo), etc.);

– Modification of the original sketch (color matching, changing contour lines, overlaying the image of the fabric on the model, in the fabric you can change the scale of the drawing, the color of the drawing, give a glitter effect, etc.);

– Creation of a model from elements;

– Creation of catalogs of models.

Subsystem “Constructor” CAD “Grace”

The model is stored as an algorithm, so at any time you can check the correctness of the construction. The algorithm consists of a sequence of operators. Each operator performs some elementary action. During the execution of the algorithm, geometric objects are created, on the basis of which model patterns are created.

Patterns built according to the algorithm are written in the form of a model consisting of patterns of a given base size and height and containing increment rates for gradation.

The Constructor subsystem implements computer technology for creating new models using any of the existing design methods: EMKO SEV, TsOTSHL, Muller, Grynszpan, … or its own original method.

The designer chooses a design technique and forms its information base: sets size and height characteristics, rules for changing for various weight groups, increases and allowances. The screen is divided into two parts: the right one, where the designer describes the process of building basic structures and modeling techniques in a special language, and the left one, where the system performs and displays the corresponding constructions on the screen.

The system calculates the position of drawing points in accordance with the algorithm formulas for the specified values of dimensional features and increments. Having built all the necessary patterns, the designer creates a model – a separate file that is used to create layouts. Repeated execution of the algorithm for other values of dimensional features provides:

– automatic gradation of the model by size and height;

– automatic construction of a model for an individual figure;

– automatic construction of a table of measures.

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