Velocity curve
Speed_De
mand_buff
Speed RPM
0.5 1.5 2.5 3.5 4.5 5.5 6.5
Speed_real
Speed_real
Speed_real
a
b
c
Kvp：a<b<c
Figure 7-4 Speed step curve after Kvp adjustment
Step 2 ：Adjustment for Kvi
Kvi is designed to eliminate static errors. It can strengthen the low frequency gain of the velocity
loop, and a large Kvi can reduce the response ability from low-frequency disturbance, thereby
improving the anti-disturbance capability in low-frequency.
When Kvi is too small, The integral time will be long. The error adjustment will be slow, and it will
take longer time to make the system entering steady state. When the integral gain of the speed
loop is too large, the error will appear and in severe cases, the motor may oscillate. Kvi should be
adjusted to the servo eliminating the error and enter a stable state efficiently.
Speed curve
Speed_Dem
and_buff
Speed RPM
0.5 1.5 2.5 3.5 4.5 5.5 6.5
Speed_real
Speed_real
Speed_real
Kvi：a<b<c
c
b
a
Figure 7-5 Speed step curve after Kvi adjustment
Generally, if the machine has more friction, the kvi should be set larger. If the entire system needs
to respond quickly, kvi should be set as small as possible or even 0. If you need to dynamically close
kvi during operation, you can use the kvi close in Din function。
⚫
Speed step curve：Curve that shows rise/fall changes.
⚫
The vibration and noise of the motor can be felt by hand touch and listening
⚫
Kvi32=1/32 of Kvi[0] ，In high resolution encoder, directly increasing the
data in the kvi[0] will lead to overshoot. At this time, you can reduce the
data in kvi[0], and fine-tune it in the kvi32
⚫
Generally,the parameters of kpp and kvi are relative. When the kpp data is
adjusted to be much larger than the factory value, the kvi should also be
appropriately increased on the basis of the factory value.
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