Kinco FD425-CA-000, Руководство пользователя, Страница: 138 / 206

Kinco FD5 系列伺服驱动器使用手册 第七章 性能调节
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Position loop tuning steps:
Step 1
： Kpp adjustment
Increasing the Kpp can increase the position loop bandwidth to reduce the positioning time
and the following error, but if the setting is too large, it will cause noise or even oscillation, and
it must be set according to the load conditions.
Kpp = 103 *
position loop bandwidth 。 The
bandwidth of the position loop cannot exceed the bandwidth of velocity loop. It is
recommended that the setting value of the position loop bandwidth be less than one quarter
of the bandwidth of the velocity loop.
Step 2
： Kvff adjustment
Increasing the Kvff can reduce the position following error and improve the dynamic response
characteristics of the entire system, but it may lead greater overshoot during acceleration and
deceleration. When the position command signal is not smooth, reducing the Kvff can reduce
the motor oscillation. When the feedforward is set to 0, if only the Kvp is used to position the
servo, the in-position time will be longer.
Kvff function can be regarded as the upper controller, such as PLC, has the opportunity to
directly control the velocity in position operating mode. In fact, the function will consume part
of the speed loop responsiveness, so the setting value needs to match the position loop and
velocity loop bandwidth.
The elastic factor of the flexible load, such as pulley, will cause the speed feedforward command
loaded to the speed loop to be unsmooth and cause the load to oscillate. In this type of load,
the position loop speed feedforward can be appropriately reduced. In a rigid load, if adjusting
the Kpp cannot eliminate the vibration generated by the motor during acceleration and
deceleration, you can also try to gradually decrease the default 100% feedforward.
Speed curve
Pos_Actual
Speed_Deman
d_buff
0.5 1.5 2.5 3.5 4.5 5.5 6.5
Zero
speed
c
b
a
Kvff ： a<b<c
Pos_Actual
Pos_Actual
Figure 7-6
Speed step curve after Kvff adjustment
Step 3 ： Kaff adjustment
Users are not advised to adjust this parameter. When the practical application requires very high
position loop response, the acceleration feedforward can be adjusted to improve the response
performance.
The acceleration feedforward function can be seen as the upper controller has the opportunity to
directly control the torque in the position operating mode. This function actually consumes some of the
current loop responsiveness, so if the settings do not match the Kvp and velocity loop bandwidth,