For example: if the acceleration and deceleration time is set too small, the servo motor will produce high inertia jitter when it suddenly starts or stops... This problem can be solved by increasing the acceleration and deceleration time respectively.
The following is a selection of netizens' analysis of the causes of servo motor jitter for your reference:
one
Viewpoint 1
When the servo motor vibrates at zero speed, it should be that the gain is set high, and the gain value can be reduced. If the motor vibrates during startup and the motor shuts down, the most likely cause is that the motor phase sequence is incorrect.
two
Viewpoint 2
1. When the PID gain adjustment is too large, it is easy to cause motor jitter, especially after adding D, so it is especially serious, so try to increase P and reduce I. It is best not to add D.
2. Jitter will also occur when the encoder wiring is incorrectly connected.
3. The load inertia is too large, replace the motor and driver with a larger one.
4. If interference at the analog input port causes jitter, add a magnetic ring to the motor input line and servo drive power input line to keep the signal line away from the power line.
5. There is also a rotary encoder interface motor. Poor grounding can easily cause vibration.
picture
Three
Viewpoint 3
① Servo wiring:
a. Use standard power cables, encoder cables, and control cables to check whether the cables are damaged;
b. Check whether there is any interference source near the control line, and whether it is parallel to or too close to nearby high-current power cables;
c. Check whether there is any change in the potential of the ground terminal, and make sure the grounding is good.
② Servo parameters:
a. The servo gain setting is too large. It is recommended to re-adjust the servo parameters manually or automatically;
b. Confirm the setting of the speed feedback filter time constant. The initial value is 0. You can try to increase the setting value;
c. The electronic gear ratio setting is too large, it is recommended to restore it to the factory settings;
d. For the resonance of servo system and mechanical system, try to adjust the harmonic filter frequency and amplitude.
③ Mechanical system:
a. The coupling connecting the motor shaft and the equipment system is offset and the mounting screws are not tightened;
b. Poor meshing of pulleys or gears can also cause load torque changes. Try to run without load. If it is normal during no-load operation, check whether there is any abnormality in the connecting part of the mechanical system;
c. Confirm whether the load inertia, torque and speed are too large, and try to run without load. If the no-load operation is normal, reduce the load or replace the drive and motor with a larger capacity.
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Four
Viewpoint 4
Servo motor jitter is caused by faults in the mechanical structure, speed loop, servo system compensation board and servo amplifier, load inertia, electrical parts, etc.
Wu
Summarize
1. The vibration caused by the mechanical structure can be divided into two situations:
1) No-load jitter:
a. The motor foundation is not strong, the stiffness is not enough, or the fixing is not tight.
b. The fan blades are damaged, destroying the mechanical balance of the rotor.
c. The machine shaft is bent or cracked. It can be solved by tightening screws, replacing fan blades, replacing machine shafts, etc.
2) If it vibrates after adding a load, it is usually caused by a fault in the transmission device. It can be judged that there are defects in the following parts:
a. The belt pulley or coupling rotates unbalanced.
b. The center lines of the couplings are inconsistent, causing the motor and the mechanical axis of the transmission to not coincide.
c. The transmission belt joint is unbalanced. It can be solved by correcting the transmission device to balance it.
2. Jitter caused by speed loop problems:
The speed loop integral gain, speed loop proportional gain, acceleration feedback gain and other parameters are inappropriate. The greater the gain, the greater the speed, the greater the inertial force, the smaller the deviation, and the easier it is to produce jitter. Setting a smaller gain can maintain speed response and reduce jitter.
3. Jitter caused by faults in the compensation board and servo amplifier of the servo system:
The motor suddenly lost power and stopped during motion, resulting in a large jitter, which was related to the improper wiring terminals of the servo amplifier BRK and the setting parameters. You can increase the acceleration and deceleration time constant and use PLC to slowly start or stop the motor so that it does not shake.
4. Jitter caused by load inertia:
Problems with the guide rails and screws cause the load inertia to increase. The rotational inertia of the guide rail and screw has a great influence on the rigidity of the servo motor transmission system. Under a fixed gain, the greater the rotational inertia, the greater the rigidity, and the easier it is to cause the motor to vibrate; the smaller the rotational inertia, the smaller the rigidity, and the less likely the motor is to vibrate. . The motor can be prevented from shaking by replacing the guide rail and screw with a smaller diameter to reduce the moment of inertia and thus the load inertia.
5. Jitter caused by electrical parts:
a. Caused by factors such as the brake not being turned on and the feedback voltage being unstable. Check whether the brake is on, add the encoder vector control zero servo function, and output a certain torque to solve the jitter by reducing the torque. If the feedback voltage is abnormal, you should first check whether the vibration cycle is related to the speed. If it is related, you should check whether there is a fault in the connection between the spindle and the spindle motor, whether the spindle and the pulse generator installed at the end of the AC spindle motor are damaged, etc., if not, Then you should check whether there is a fault on the printed circuit board, and the circuit board needs to be inspected or readjusted.
b. Sudden shaking of the motor during operation is mostly caused by phase loss. You should focus on checking whether the fuse melt is blown, whether the switch contact is good, and measure whether there is power in each phase of the power grid.
