The difference between NC and CNC(2)

4. To be processed track monitoring

This technology has been widely used. The technology has many performance differences that distinguish its working mode in low-end control systems from that in high-end control systems. Generally speaking, CNC realizes the pre-processing of the program by monitoring the processing track, so as to ensure that it can obtain more excellent acceleration/deceleration control. According to the performance of different CNCs, the number of program blocks required for monitoring the track to be processed varies from two to hundreds, which mainly depends on the shortest processing time of the part program and the acceleration/deceleration time constant. Generally speaking, in order to meet the processing requirements, at least fifteen track monitoring program blocks to be processed are required.

5. Digital Servo Control

The development of digital servo system is so rapid that most machine tool manufacturers choose this system as the servo control system of machine tool. After using this system, CNC can control the servo system more timely, and CNC control of the machine tool has become more precise.

The functions of the digital servo system are as follows:

1) The sampling speed of the current loop will be increased, coupled with the improvement of the current loop control, thereby reducing the temperature rise of the motor. In this way, not only can the life of the motor be extended, but also the heat transferred to the ball screw can be reduced, thereby improving the accuracy of the screw. In addition, the acceleration of the sampling speed can also increase the gain of the speed loop, which helps to improve the overall performance of the machine tool.

2) Since many new CNCs use high-speed sequences to connect to the servo loop, through the communication link, the CNC can obtain more information about the work of the motor and the drive device. This can improve the maintenance performance of the machine tool.

3) Continuous position feedback allows high-precision machining under high-speed feed. The acceleration of CNC calculation makes the rate of position feedback become a bottleneck restricting the operating speed of the machine tool. In the traditional feedback method, as the sampling speed of the external encoder of CNC and electronic equipment changes, the feedback speed is restricted by the signal type. Using serial feedback, this problem will be well resolved. Even if the machine tool runs at a high speed, it can achieve precise feedback accuracy.