CNC technology originated from the needs of the development of the aviation industry. In the late 1940s, a helicopter company in the United States proposed the initial idea of CNC machine tools. In 1952, the Massachusetts Institute of Technology developed a three-coordinate CNC milling machine. In the mid-1950s such CNC milling machines were already available for machining aircraft parts. In the 1960s, the CNC system and programming work became more and more mature and perfect, and CNC machine tools have been used in various industrial sectors, but the aerospace industry has always been the largest user of CNC machine tools. Some large aerospace factories are equipped with hundreds of CNC machines, mainly cutting machines. The CNC-machined parts include integral wall panels, girders, skins, bulkheads, propellers of aircraft and rockets, mold cavities of aero-engine casings, shafts, disks, and blades, and special cavity surfaces of liquid rocket engine combustion chambers, etc. . In the early stage of the development of CNC machine tools, the CNC machine tools with continuous trajectory were mainly based on continuous trajectory control.
