HISTORICAL PERSPECTIVE ON CAD

Graphical representation of data, in many ways, forms the basis of CAD. An early application of computer graphics was used in the SAGE (Semi-Automatic Ground Environment) Air Defense Command and Control System in the 1950s. SAGE converted radar information into computer-generated images on a cathode ray tube (CRT) display. It also used an input device, the light pen, to select information directly from the CRT screen.

Another significant advancement in computer graphics technology occurred in 1963, when Ivan Sutherland, in his doctoral thesis at MIT, described the SKETCHPAD (Fig. 1) system. A Lincoln TX-2 computer drove the SKETCHPAD system. SKETCHPAD is a graphic user interface that enables a design to be input into a computer using a light pen on the CRT monitor. With SKETCHPAD, images could be created and manipulated using the light pen. Graphical manipulations such as translation, rotation, and scaling could all be accomplished on-screen using SKETCHPAD. Computer applications based on Sutherland’s approach have become known as interactive computer graphics (ICG), which are the foundation of CAD design processes. The graphical capabilities of SKETCHPAD showed the potential for computerized drawing in design.

During his time as a professor of electrical engineering at the University of Utah, Sutherland continued his research on head-mounted displays (HMDs), the precursor to virtual reality head displays. The field of computer graphics (Fig. 2), as we know it today, was born from among the many new ideas and innovations created by the researchers who made the University a hub for this kind of research. Together with Dave Evans, the founder of the University’s.

Figure 1 Ivan E. Sutherland and the SKETCHPAD system.

Figure 2 Image on a line drawing graphics display.

Computer Science Department, Sutherland co-founded Evans and Sutherland in 1968, which later went on to pioneer computer modeling systems and software.

While at the California Institute of Technology, Sutherland served as the chairman of the Computer Science Department from 1976 to 1980. While he was there, he helped to introduce the integrated circuit design to academia. Together with Professor Carver Mead, they developed the science of combining the mathematics of computing with the physics of real transistors and real wires and subsequently went on to make integrated circuit design a proper field of academic study. In 1980, Sutherland left Caltech and launched the company Sutherland, Sproull, and Associates. Bought by Sun Labs in 1990, the acquisition formed the basis for Sun Microsystems Laboratories.

The high cost of computer hardware in the 1960s limited the use of ICG systems to large corporations such as those in the automotive and aerospace industries, which could justify the initial investment. With the rapid development of computer technology, computers became more powerful, with faster processors and greater data storage capabilities. As computer cost decreased, systems became more affordable to smaller companies allowing entrepreneurs to innovate using CAD tools and technologies.

In more recent times, increased impact of computer-aided design has been facilitated by advances in Web-based technologies and standards, use of mobile computing platforms and devices, cloud-based storage, software as a service, and functional integration into enterprisewide systems. Additionally, the proliferation of CAD systems running on a wide variety of platforms has promoted global collaboration as well as concurrent design and manufacturing approaches. In the view of many, CAD has become a necessary business tool for any engineering, design, or architectural firm.

Source:

Mechanical Engineers’ Handbook, Volume 2: Design, Instrumentation, and Controls