CNC lathe manufacturers talk about the reasons for small CNC lathe oscillation:
The experience of CNC lathe manufacturers has learned that the position loop is bad and causes the output voltage to be unstable; the vibration caused by the poor speed loop; the adjustable position of the servo system is too large, causing the voltage output to be distorted; the transmission machinery is as large as the screw gap. Distortion of the output parameters of these control loops or excessive mechanical transmission clearance are major factors in causing vibration. They can all be parameter optimized through the servo control system.
The basic measures for eliminating the oscillation of the CNC lathe:
1. Oscillation caused by closed-loop servo system
Some CNC servo systems use a semi-closed loop device, and the full closed loop servo system must be parameterized under the premise that its local semi-closed loop system does not oscillate, so the two are similar.
2. Reduce the position loop gain
There is a reference standard value in the servo system. Oscillation can reduce the gain appropriately, but it cannot be reduced too much because the steady-state error of the system is guaranteed.
3. Reduce the load inertia ratio
The load inertia ratio is generally set at about 70% of the parameter shown when vibration occurs. If the fault cannot be eliminated, it is not appropriate to continue to reduce the parameter value.
4. Add proportional integrator (PID)
The proportional integrator is a multi-function controller, which not only can effectively proportionally increase the current and voltage signals, but also adjust the output signal lag to lead the problem. Oscillation faults sometimes occur due to the lag of the output current voltage. At this time, the output current voltage phase can be adjusted by the PID.
Oscillation faults in CNC lathes usually occur in the mechanical part and the feed servo system. There are many reasons for the oscillation. In addition to the mechanical non-removable transmission gap, elastic deformation, frictional resistance and other factors, the influence of the relevant parameters of the servo system is also an important aspect. The servo system has AC and DC points.
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