For the CNC internal grinder control form and feed drive system, the cnc grinder machine can be divided into two different types, namely open-loop control systems and closed-loop control system. Depending on the control mode, the feed drive system is divided into stepping drive system and feed drive servo system. Difference between open-loop and closed-loop is depends on whether the use of work piece of the position and velocity feedback detection. Generally, Shenyang Hermos CNC Machine Tools use a closed-loop servo motor as the driving element. And the closed-loop control system is divided into semi-closed loop, closed loop, closed loop three control hybrid form.

1. The Form of Open-loop control system
Open-loop control form without position feedback device, so called open-loop control, open loop control system is generally used as a stepping-driven servo actuator. The use of open-loop control in the form of CNC grinding machine structure is simple, low manufacturing costs, but can not be automated through the feedback error detection and correction. Simple NC open-loop control of the CNC grinder suitable for processing less precision, little change within the economy on a CNC grinder.

2. Form of Semi-closed loop control System
Usually the form of semi-closed loop control of the position detection element is mounted on the motor shaft, to precisely control the angle of the motor, Then linear displacement table, the error on the transmission chain can be converted into a through ball screw the angle compensated by the NC device, improve the accuracy of the CNC grinder, so accuracy is moderate, the majority of small CNC surface grinder used is a semi-closed loop control form.

3. Form of Closed loop control
Closed loop control mode is the actual location of the mobile value obtain directly from the moving parts within the CNC grinder, this control method requires the CNC grinder with strong rigidity, Driving transmission gap and improve the position gain, closed loop numerical form the CNC grinder commonly used as a linear motor actuator drive system. CNC grinder inside this closed loop control method widely used in the large-scale high precision CNC grinder.

4. Form of Mixed closed-loop control
Closed-loop control in the form of hybrid combines a high position gain semi-closed loop control, access to high speed and excellent dynamic characteristics. Took advantage of the closed loop control in the form of amendments to transmission errors. This hybrid type of closed loop form suitable for heavy-duty, ultra heavy-duty CNC grinder.