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Numerical Control and Computer Numerical Control
Published in Helmi Youssef, Hassan El-Hofy, Traditional Machining Technology, 2020
Earlier systems of NC machines consisted of a specially built control unit permanently connected to the machine tool. They are relatively inflexible, as they are special-purpose machine tools. Developments in the area of miniaturization and integration of circuits have led to the introduction of new, small, and powerful computers that are used to control the machine tools (CNC) instead of a conventional controller. The advantages of CNC are related to the control system, which allows a great deal of flexibility, unobtainable with NC. DNC involves controlling more than one machine using the same computer and data transmission lines. The major advantage of CNC and DNC over NC is that punched tapes are not used directly to control the machine tool. Instead, all information flows from a computer that interfaces with each MCU (see Figure 9.2).
Framework and modelling of inclusive manufacturing system
Published in International Journal of Computer Integrated Manufacturing, 2019
Sube Singh, Biswajit Mahanty, Manoj Kumar Tiwari
Since, the inception of manufacturing, abundant changes have been observed in this domain to make manufacturing system simple, rapid, economical, customised, personalised and sustainable (Bao et al. 2016). For a better understanding, the observed changes can be classified into two types, (1) technology-based revolutions and (2) production-based revolutions. The technological revolutions started at the end of the eighteenth century with implementation of mechanised facilities in manufacturing industries by using steam and water power known as the first industrial revolution. In the second industrial revolution, mass production was one of the main targets with adoption of labour division scheme and electrical energy in manufacturing. The numerical control, computer numerical control (CNC) and distributed/direct numerical control were significant contributions in the third industrial revolution (Liao et al. 2017). The current era of manufacturing is perceived as a fourth industrial revolution, and it is widely known as Industry 4.0 (Lasi et al. 2014). Similarly, in past few decades, several production-based revolutions have been observed such as in 1960s, the focus was to increase production and later on, it changed to cost reduction of a product in 1970s. In 1980s, the quality of a product was a decisive factor in production, and then motive had been changed in 1990s towards minimising the market time by adopting rapid or just-in-time production system (Zhang et al. 2014). In recent, the researchers have focused on improving the service, security, knowledge and information sharing in manufacturing systems (Wu et al. 2015). Figure 1 depicts all the developments happened in manufacturing systems in last more than 200 years. The diagram has been extended by adding a few more information regarding industrial revolutions, driven and competitive factors in original work of Tao, Ying Cheng and Nee (2017). The purpose of Figure 1 is to illustrate the shifting of research trend in manufacturing domain on industrial revolutions timeline.