| Computer-aided design (CAD) is the use | | | | coined by Doug Ross at MIT in 1959.[6] |
| of a wide range of computer-based tools | | | | It is argued that a turning point was |
| that assist engineers, architects and | | | | the development of SKETCHPAD system in |
| other design professionals in their | | | | MIT in 1963 by Ivan Sutherland (who |
| design activities. It is the main | | | | later created a graphics technology |
| geometry authoring tool within the | | | | company with Dr. David Evans). The |
| Product Lifecycle Management process and | | | | distinctive feature of SKETCHPAD was |
| involves both software and sometimes | | | | that it allowed the designer to interact |
| special-purpose hardware. Current | | | | with his computer graphically: the |
| packages range from 2D vector based | | | | design can be fed into the computer by |
| drafting systems to 3D solid and surface | | | | drawing on a CRT monitor with a light |
| modellers. | | | | pen. Effectively, it was a prototype of |
| CAD is sometimes translated as | | | | graphical user interface, an |
| "computer-assisted", "computer-aided | | | | indispensable feature of modern CAD. |
| drafting", or a similar phrase. Related | | | | First commercial applications of CAD |
| acronyms are CADD, which stands for | | | | were in large companies in the |
| "computer-aided design and drafting", | | | | automotive and aerospace industries, as |
| CAID for Computer-aided Industrial | | | | well as in electronics. Only large |
| Design and CAAD, for "computer-aided | | | | corporations could afford the computers |
| architectural design". All these terms | | | | capable of performing the calculations. |
| are essentially synonymous, but there | | | | Notable company projects were at GM (Dr. |
| are some subtle differences in meaning | | | | Patrick J.Hanratty) with DAC-1 (Design |
| and application. | | | | Augmented by Computer) 1964; Lockhead |
| CAD was originally the three letter | | | | projects; Bell GRAPHIC 1 and at Renault |
| acronym for "Computer Aided Draughting" | | | | (Bezier) – UNISURF 1971 car body |
| as in the early days CAD was really a | | | | design and tooling. |
| replacement for the tradition draughting | | | | One of the most influential events in |
| board. But now is the term is often | | | | the development of CAD was the founding |
| interchanged with "Computer Aided | | | | of MCS (Manufacturing and Consulting |
| Design" to reflect the fact that modern | | | | Services Inc.) in 1971 by Dr. P. J. |
| CAD tools do much more than just | | | | Hanratty[7], who wrote the system ADAM |
| draughting. | | | | (Automated Drafting And Machining) but |
| Introduction | | | | more importantly supplied code to |
| CAD is used to design, develop and | | | | companies such as McDonnell Douglas |
| optimize products, which can be goods | | | | (Unigraphics), Computervision (CADDS), |
| used by end consumers or intermediate | | | | Calma, Gerber, Autotrol and Control |
| goods used in other products. CAD is | | | | Data. |
| also extensively used in the design of | | | | As computers became more affordable, the |
| tools and machinery used in the | | | | application areas have gradually |
| manufacture of components, and in the | | | | expanded. The development of CAD |
| drafting and design of all types of | | | | software for personal desk-top computers |
| buildings, from small residential types | | | | was the impetus for almost universal |
| (houses) to the largest commercial and | | | | application in all areas of |
| industrial structures (hospitals and | | | | construction. |
| factories). | | | | Other key points in the 1960s and 1970s |
| CAD is mainly used for detailed | | | | would be the foundation of CAD systems |
| engineering of 3D models and/or 2D | | | | United Computing, Intergraph, IBM, |
| drawings of physical components, but it | | | | Intergraph IGDS in 1974 (which led to |
| is also used throughout the engineering | | | | Bentley MicroStation in 1984) |
| process from conceptual design and | | | | CAD implementations have evolved |
| layout of products, through strength and | | | | dramatically since then. Initially, with |
| dynamic analysis of assemblies to | | | | 2D in the 1970s, it was typically |
| definition of manufacturing methods of | | | | limited to producing drawings similar to |
| components. | | | | hand-drafted drawings. Advances in |
| CAD has become an especially important | | | | programming and computer hardware, |
| technology with benefits, such as lower | | | | notably solid modeling in the 1980s, |
| product development costs and a greatly | | | | have allowed more versatile applications |
| shortened design cycle, because CAD | | | | of computers in design activities. |
| enables designers to lay out and develop | | | | Key products for 1981 were the solid |
| their work on screen, print it out and | | | | modelling packages -Romulus (ShapeData) |
| save it for future editing, saving a lot | | | | and Uni-Solid (Unigraphics) based on |
| of time on their drawings. | | | | PADL-2 and the release of the surface |
| Designers have long used computers for | | | | modeler CATIA (Dassault Systemes). |
| their calculations. Initial developments | | | | Autodesk was founded 1982 by John |
| were carried out in the 1960s within the | | | | Walker, which led to the 2D system |
| aircraft and automotive industries in | | | | AutoCAD. The next milestone was the |
| the area of 3D surface construction and | | | | release of Pro/ENGINEER in 1988, which |
| NC programming, most of it independent | | | | heralded greater usage of feature-based |
| of one another and often not publicly | | | | modeling methods and parametric linking |
| published until much later. Some of the | | | | of the parameters of features. Also of |
| mathematical description work on curves | | | | importance to the development of CAD was |
| was developed in the early 1940s by | | | | the development of the B-rep solid |
| Isaac Jacob Schoenberg, Apalatequi | | | | modeling kernels (engines for |
| (Douglas Aircraft) and Roy Liming (North | | | | manipulating geometrically and |
| American Aircraft), however probably the | | | | topologically consistent 3D objects) |
| most important work on polynomial curves | | | | Parasolid (ShapeData) and ACIS (Spatial |
| and sculptured surface was done by | | | | Technology Inc.) at the end of the 1980s |
| Pierre Bezier (Renault), Paul de | | | | and beginning of the 1990s, both |
| Casteljau (Citroen), Steven Anson Coons | | | | inspired by the work of Ian Braid. This |
| (MIT, Ford), James Ferguson (Boeing), | | | | led to the release of mid-range packages |
| Carl de Boor (GM), Birkhoff (GM) and | | | | such as SolidWorks in 1995, SolidEdge |
| Garabedian (GM) in the 1960s and W. | | | | (Intergraph) in 1996, and IronCAD in |
| Gordon (GM) and R. Riesenfeld in the | | | | 1998. Today CAD is one of the main tools |
| 1970s. | | | | used in designing products. |
| The term "computer-aided design" was | | | | |