Motor & 9505

[tlp0605]

Hi,

I am new to the system identification and control design toolkit. I have cRIO 9505. I have an old printer which I want to find its transfer function. The input is a current and I want to monitor the movement of the motor (horizontal). I would like to know how to get the transfer function of this current input and position output.

I have looked at the user manual of 9505 and there is a NI 9505 block diagram (pg 8 in the version I have). On page 10, there is a current loop. Why is there a Kp and Ki?? Are they there to make sure that the current to the motor is closed to or equal to the current command (if current command is within current limit)??

Thanx

Lee

[VuD]

Hello Lee,

In regards to your question, yes, the Proportional-Integral (PI) controller is used to manipulate the difference between the measured variable and the set point both proportionally and through offset.  I have also attached a link to a Knowledgebase document on our website  which I found using the following keywords “PID algorithm effects”.  Please let us know if you would like any further clarification on this issue.

Effects of the Proportional, Integral, and Derivative Components of the PID Algorithm on the System ...   

Best regards,

Vu D
Applications Engineer