CNC machine tool is the general name of digital control machine tool. It is a high-grade typical product of mechatronics, which is composed of modern precision mechanical design and CNC manufacturing technology, computer technology, communication technology, automatic control technology, detection technology, power electronics and microelectronics technology, motor and new material technology, hydraulic and pneumatic technology, optical and electrical technology, etc At the same time, it is a modern equipment with high precision, high flexibility, high efficiency and high automation.

The servo system consists of feed servo system and spindle servo system. The feed system is used to control the laser cutting feed motion of each coordinate axis of the machine tool. It is mainly composed of the following parts: servo drive circuit, servo drive device (motor), position detection device, mechanical transmission mechanism and executive parts.

The spindle servo system is used to control the rotation of the machine tool spindle and the torque and power in the cutting process, usually speed control is the main control. CNC machine tools have the following requirements for the function of servo system:

• 1) high precision.
• 2) Good stability.
• 3) Quick response.
• 4) Low speed and high torque.
• 5) Wide speed range.
• 6) Have the ability of retrograde.

Some indexes of servo system are as follows: uniform, stable and no creeping in the range of 1 ~ 2400mm / min; under 1 mm / min, it has a certain instantaneous speed, but the average cnc machining speed is required to be very low; at zero speed, the positioning error does not exceed the allowable range; when the rated distance changes, the static speed drop is less than 5%, and the dynamic speed drop is less than 10%; the motor speed is from zero to more The positioning accuracy of the position servo system should reach 1pm or even 0.1pm.