One：

When the servo motor vibrates at zero speed, the gain is probably set high. We can directly reduce the gain value. For example, if the motor is vibrated when started up and the alarm stops ringing, the maximum possibility is that the phase sequence of the servo motor is out of order.  Check whether the servo motor U, V, W, PE is wired correctly.

Two：

1. When the PID gain adjustment is too large, it is easy to cause the servo motor to vibrate, especially after adding D, more serious. Try to increase P, reduce I, and add D;

2. The vibration also happens when the servo motor encoder is connected wrongly;

3, When the load inertia is too large, replace it with the larger servo motor and servo drive;

4. When the vibration is caused by the analog input port interferes, add the magnetic ring to the servo motor input line and servo driver power input line to keep the signal line away from the power line;

5, The vibration is easily caused when the grounding wire of rotary encoder interface motorisnot correctly connected.

Three：

1 Servo wiring:

a. Use standard power cable, check whether encoder cable, control cable, and cable are damaged;

b. Check whether there is a disturbance source near the control line, and whether it is parallel or close to each other adjacent to the high-current power cable;

c. Check if the ground terminal potential changes, and ensure that the grounding is good.

2 servo parameters:

a. When thehe servo gain setting is too large, it is recommended to re-adjust the servo driver parameters by manual or automatic method.

b. Confirm the setting of time constant of the speed feedback filter. When the initial value is 0, try increasing the setting value.

c. When the electronic gear ratio setting is too large, it is recommended to return to the factory setting value;

d. When there is a resonance of the servo system and the mechanical system, try to adjust the notch filter frequency and amplitude.

3 Mechanical system:

a. When the coupling connecting the servo motor shaft with the equipment system is offset, the mounting screws should be tightened;

b. Poor occlusion of the pulley or gear will also cause the load torque to change. Try to run at no load, and if the load is normal during no-load operation, check whether the joint part of the mechanical system is abnormal.

c. Check whether the load inertia, torque and speed are too large. If it is, try to run at no load. If the no-load operation is normal, reduce the load or replace the servo motor driver and servo motor with more inertia.

Four：

Servo motor chattering is caused by mechanical structures, speed loops, compensation plates and servo amplifiers of the servo system, load inertia, and electrical parts etc:

1. The vibration caused by mechanical structure can be divided into three conditions:

1) No-load vibration:

a. The servo motor foundation is not strong, the rigidity is not enough or the fixing is not tight;

b. The servo motor fan blade is damaged, which destroys the mechanical balance of the rotor;

c. The servo motor output shaft is bent or cracked, and can be handled by tightening the screw, replacing the fan blade, and  servo motor output shaft.

2) If the vibration is caused by the load, it is generally caused by the fault of the transmission device, and the shortcomings of the following parts can be judged:

a. The belt wheel or the coupling is not balanced;

b. The coupling is not concentric so that the servo motor is not concentric with the mechanical shaft of the transmission;

c. The transmission belt joint is unbalanced and can be treated by correcting the transmission to balance it.

2. The vibration caused by the speed loop problem:

Parameters such as speed loop integral gain, speed loop proportional gain, and acceleration feedback gain are not set properly. The larger the gain, the larger the speed, the larger the inertial force, the smaller the deviation, the more likely the vibration is generated, and the smaller the gain can maintain the speed response and the vibration is less likely to occur.

3. Vibrating caused by the compensation plate of the servo system and the servo driver failure:

Sudden power failure during the movement of the servo motor causes great vibration. It is related to the BRK terminal of the servo driver and improper setting parameters. The acceleration/deceleration time constant can be increased, and the servo motor can be slowly started or stopped by the PLC to make it not vibrate.

4. The vibration caused by the load inertia:

The problem of the guide rail and the lead screw cause the load inertia to increase. The moving inertia of the guide rail and the lead screw has a great influence on the rigidity of the servo motor drive system. Under the fixed gain, the greater the motion inertia, the greater the rigidity, and the more likely the servo motor will vibrate; The smaller the motion inertia, the smaller the rigidity, the less the servo motor is more likely to vibrate. The servo motor can be non-vibrated by replacing the smaller diameter guide rail and the lead screw to reduce the moment of inertia and reduce the load inertia

5. The vibration caused by the electrical part:

a. The power-off brake is not turned on, the feedback voltage is unstable and other factors are caused. Check whether the power-off brake is turned on. By adding the encoder vector to control the zero servo function, the torque reduction method is used to output a certain torque to solve the vibration. If the feedback voltage is abnormal, check whether the vibration period is related to the speed. If it is related, check whether there is a fault in the link between the spindle and the spindle motor, whether the spindle and the pulse generator installed at the tail of the spindle motor are damaged etc. If not, you should check the board for any faults, or readjust it.

b. The servo motor suddenly vibrates during operation, which is mostly caused by unstable voltage.  It is important to check whether the fuse melt is blown, and the switch is good or not, and measure whether there is electricity in each phase of the grid.