The digital control system, also known as the computer control system, is based on the rapid development of automatic control technology and computer technology. In the mid-1950s, classical control theory has developed very maturely and has been successfully applied in many engineering fields. Specifically, the digital control system refers to an automatic control system that implements various control functions using digital technology. The main type is computer-based control system, including computer monitoring system, direct digital control system, computer multi-level control system and distributed control system.
The digital program control system refers to a digital control system that uses digital codes representing processing sequences, processing methods, and processing parameters as control commands. The simple digital program control system is called a numerical control (NC) system. In the numerical control system, a dedicated electronic computer is usually provided, and the processing information reflecting the processing technology and the operation steps is pre-recorded on the punched tape, the punched card, the magnetic tape or the magnetic disk by digital codes. When the system is working, the reading mechanism sends the code to the computer in turn and converts it into a corresponding form of electrical pulse, which is used to control the working machine to complete the various processing steps in sequence. The numerical control system has high processing precision and processing efficiency, and is especially suitable for single-piece or small-batch production with complicated processes. It is widely used in tool manufacturing, machining, automotive and shipbuilding industries.