The gain adjustment steps for position control are as follows:
1. Set the appropriate moment of inertia ratio;
2. Set the time loop integral time constant to a larger value;
3, increase the speed loop gain, if the mechanical vibration, slightly smaller;
4, reduce the speed loop integral time constant, if the mechanical vibration, slightly increase;
5. Increase the position loop gain. If the machine vibrates, slightly reduce it;
6. If the mechanical system cannot resonate and the gain cannot be obtained, and the servo application requirements are not obtained, the torque low-pass filter or the trap can be adjusted to suppress the resonance of the mechanical system; then the above steps are re-operated to improve the servo. Sex. It is recommended to use a torque low-pass filter first. If the torque low-pass filter is not effective, consider the notch filter.
7. If shorter positioning time and smaller position tracking error are required, the speed feedforward, that is, the speed feedforward gain, may be appropriately increased, but it should not exceed 80%;
The gain adjustment steps for speed control are as follows:
1. Set the appropriate moment of inertia ratio;
2. Set the time loop integral time constant to a larger value;
3, increase the speed loop gain, if the mechanical vibration, slightly smaller;
4, reduce the speed loop integral time constant, if the mechanical vibration, slightly increase;
5. If the mechanical system cannot resonate and the gain cannot be obtained, and the servo application requirements are not obtained, the torque low-pass filter or the trap can be adjusted to suppress the resonance of the mechanical system; then the above steps are re-operated to improve the servo. Sex. It is recommended to use a torque low-pass filter first. If the torque low-pass filter is not effective, consider the notch filter.
Speed loop gain:
The speed loop gain directly determines the response bandwidth of the speed loop. In the case where the mechanical system does not generate resonance or noise, increase the speed loop gain, the faster the speed response, and the better the followability to the speed. However, excessive speed loop gain can cause mechanical resonance.
Speed loop bandwidth (Hz) = (1 + G) / (1 + JL / JM) * speed loop gain (Hz)
Where: G is the moment of inertia ratio, JL is the moment of inertia of the load converted to the motor shaft, and JM is the moment of inertia of the rotor of the motor. When the set value G=JL/JM, the speed loop gain is the speed loop bandwidth.
Speed loop integral time constant:
The speed loop integral time constant can effectively eliminate the speed steady state error and quickly respond to subtle speed changes. When the mechanical system does not generate resonance or noise, reducing the speed loop integral time constant can increase the system rigidity and reduce the steady-state error. If the load inertia ratio is large or there is a resonance factor in the mechanical system, the speed loop integral time constant must be increased to reduce the effect of the integral, otherwise the mechanical system is prone to resonance. If the inertia ratio parameter G is set to JL/JM, the speed loop integral time constant is:
Speed loop integral time constant (ms) = 4000 / (2 * pi * speed loop gain (Hz)) where: pi is the pi.
Position loop gain:
The position loop gain directly determines the reaction speed of the position loop. In the case where the mechanical system does not generate resonance or noise, the position loop gain is increased, the position tracking error is reduced, and the positioning time is shortened. However, excessive position loop gain can also cause mechanical system jitter or position overshoot. The location loop bandwidth cannot be higher than the speed loop bandwidth, as follows:
Position loop bandwidth (Hz) <= speed loop bandwidth (Hz) / 4
If the inertia ratio parameter G is set to JL/JM, the position loop gain can be calculated:
Position loop gain (1/s) <= 2*pi* speed loop gain (Hz) / 4
