Application of stepping motor and driver in CNC Machine Tool
1. Open-loop control system open-loop control system refers to the control system without reaction equipment, which consists of stepping motor drive circuit and stepping motor.
The numerical control equipment sends out pulse signals through control and operation, and each pulse signal makes the stepping motor rotate at a certain angle and move a certain distance through the ball screw propulsion platform.
This kind of servo mechanism is relatively simple, stable in operation and easy to master and use, but the improvement of accuracy and speed is limited.
2. Semi-closed-loop control system the semi-closed-loop control system is to install angular displacement detection equipment in the servo mechanism of the open-loop control system, and directly detect the displacement of the moving parts by detecting the ball screw angle of the servo mechanism, then it is reflected in the comparator of the numerical control equipment, compared with the input original instruction displacement value, and controlled with the compared difference value to make up the displacement of the moving parts until the difference value is eliminated.
This kind of servo mechanism can achieve better precision, speed and dynamic characteristics than open-loop servo mechanism, and is selected for most small and medium-sized numerical control machine tools.
3. Closed-loop control system the closed-loop control system is to directly install linear azimuth detection equipment on the orientation of moving parts of the machine tool, and react the detected practical displacement to the comparator of the numerical control equipment, compared with the input original instruction displacement value, the moving part is controlled by the compared difference value to make up the displacement, and the movement is not stopped until the difference value is eliminated, thus achieving a precise positioning control system.
The positioning accuracy of the closed-loop control system is higher than that of the semi-closed-loop control system, but the structure is relatively messy and it is difficult to debug and maintain. It is commonly used in high-precision and large-scale numerical control machine tools. TAG