There are two ways to return to the reference point of the machine tool according to the different ways in which the machine tool detection element detects the origin signal. One is the grid point method, and the other is the magnetic switching method. According to the different measurement methods of detection elements, it is divided into absolute pulse encoder and incremental pulse encoder.
Grid point method: in the grid point method, the detector generates a grid point or a zero position pulse at the same time with the motor turning signal. After installing a deceleration bump and a deceleration switch on the machine body, the first grid point or zero position signal detected by the CNC system is the origin. The characteristic of the grid point method is that if the speed approaching the origin is less than a fixed value, the servo motor always stops at the same point, that is, after the operation of returning to the origin, the origin of the machine tool is maintained well. At present, almost most CNC machine tools use the grid method. There are three ways to return to the origin of the machine tool using the grid method.
1. The machine tool that uses the incremental detection feedback element returns to the machine tool origin for the first time after starting up.
2. After the installation of the machine tool using the absolute detection feedback element, the machine tool starts up and returns to the original point for the first time during debugging.
3. After the grid point offset parameter setting is adjusted, the machine tool returns to the original point manually for the first time.
