Numerical control technology originated from the needs of the aviation industry, in the late 1940s, an American helicopter company proposed.
The initial idea of CNC machine tools, in 1952, the Massachusetts Institute of Technology developed a three-dimensional CNC milling machine. This type of CNC milling machine has been used for machining aircraft parts in the mid-1950s. In the 1960s, numerical control system and programming work is increasingly mature and perfect, numerical control machine tools have been used in various industrial sectors, but the aerospace industry is always the largest user of numerical control machine tools. Some large aviation factories are equipped with hundreds of CNC machine tools, mainly cutting machine tools. The parts processed by NUMERICAL control include integral panels, girders, skins, compartments, propellers, aero-engine casing, shafts, disks, blade mold cavities and special cavity surfaces of liquid rocket engine combustion chambers, etc. At the beginning of the development of CNC machine tools, CNC machine tools with continuous trajectory are mainly controlled by continuous trajectory.
Continuous trajectory control, also known as contour control, requires the tool to move according to the specified trajectory relative to the parts. After the development of point control CNC machine tools. Point-position control refers to the movement of the tool from one point to another, so long as it reaches the target precisely in the end, regardless of the movement path.