Origin of Computer Aided Design (Part 1)

Origin of Computer Aided Design (Part 1)

Origin of Computer Aided Design - multi-part review of the history

CAD software, also referred to as Computer Aided Design software and in the past as computer aided drafting software, refers to software programs that assist engineers and designers in a wide variety of industries to design and manufacture physical products ranging from buildings, bridges, roads, aircraft, ships and cars to digital cameras, mobile phones, TVs, clothes and of course computers! CAD software is often referred to as CAD CAM software ('CAM' is the acronym for Computer Aided Machining).

While he could never have foreseen today's CAD software, no CAD software history would be complete unless it started with the mathematician Euclid of Alexandria, who, in his 350 B.C. treatise on mathematics "The Elements" expounded many of the postulates and axioms that are the foundations of the Euclidian geometry upon which today's CAD software systems are built.

It was more than 2,300 years after Euclid that the first true CAD software, a very innovative system (although of course primitive compared to today's CAD software) called "Sketchpad" was developed by Ivan Sutherland as part oh his PhD thesis at MIT in the early 1960s. Sketchpad was especially innovative CAD software because the designer interacted with the computer graphically by using a light pen to draw on the computer's monitor. It is a tribute to Ivan Sutherland's ingenuity that even in 2004, when operations which took hours on 1960s computer technology can be executed in less than a millionth of a second and touch-sensitive TFT combination display/input devices are readily available, there is no leading CAD software that has yet incorporated such directness into its user interface.

Sketchpad was the world's first CAD software but the first commercial CAM software system, a numerical control programming tool named PRONTO, had already been developed in 1957 by Dr. Patrick J. Hanratty. For that reason it is Dr. Hanratty who is most often referred to as "the father of CAD CAM".

Due to the very high cost of early computers and to the unique mechanical engineering requirements of aircraft and automobiles, large aerospace and automotive companies were the earliest commercial users of CAD software. First-generation CAD software systems were typically 2D drafting applications developed by a manufacturer's internal IT group (often collaborating with university researchers) and primarily intended to automate repetitive drafting chores. Dr. Hanratty co-designed one such CAD system, named DAC (Design Automated by Computer) at General Motors Research Laboratories in the mid 1960s. Proprietary CAD software programs were also developed by McDonnell-Douglas (CADD released in 1966), Ford (PDGS released in 1967), Lockheed (CADAM released in 1967) and many others.

Also in the mid 1960s, the Digigraphics division of Control Data Corporation released the first commercially available CAD software system. The system was a successor to ITEK's earlier CAD software research system (which was named "The Electronic Drafting Machine" and ran on a Digital Equipment Corp. PDP-1 mainframe computer) and as with the Sketchpad CAD software, input was made using a light pen. Digigraphics was priced at $500,000 per unit and only a very few units were ever sold.

Much of the early pioneering research in 2D CAD software was performed at what was then MIT's Mathematical Laboratory (now the Department of Computer Science). European researchers were also becoming active though and in 1965, Charles Lang's team. including Donald Welbourn and A.R.Forrest, at Cambridge University's Computing Laboratory began serious research into 3D modeling CAD software. The commercial benefits of Cambridge University's 3D CAD software research did not begin to appear until the 1970 however, elsewhere in mid 1960s Europe, French researchers were doing pioneering work into complex 3D curve and surface geometry computation.Citroen's de Casteljau made fundamental strides in computing complex 3D curve geometry and Bezier (at Renault) published his breakthrough research, incorporating some of de Casteljau's algorithms, in the late 1960s. The work of both de Casteljau and Bezier continues to be one of the foundations of 3D CAD software to the present time. Both MIT (S.A.Coons in 1967) and Cambridge University (A.R.Forrest, one of Charles Lang's team, in 1968) were also very active in furthering research into the implementation of complex 3D curve and surface modeling in CAD software.

Toward the end of the 1960s, interest in the commercial applications of CAD software was growing and by the end of the decade many CAD software companies, including, Applicon, Auto-trol, Computervision (which sold its first commercial CAD software license to Xerox in 1969), Evans & Sutherland, the McAuto division of McDonnell-Douglas (actually established in 1960), SDRC (Structural Dynamics Research Corp.) and United Computing had been established.

Despite later waves of technology change, rapid growth and inevitable mergers and acquisitions, many of those early CAD software companies continue to be successful; some under their original name (for example Auto-trol) and some under changed names (for example United Computing which is now UGS). Early pioneering researchers such as Dr. Hanratty, still the active President of MCS (Manufacturing and Consulting Services), Dr. Sutherland, Charles Lang and others continue to be very influential.

Credit for this article goes to CADAZZ.