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PI Speed Control

Hi All,

 

I was wanting some help with making the PI controller work in my VI. I am using it to control the speed fo a DC motor. The range of PWM is between 1120-1920 with 1520 being stopped. I have trued tuning the controller but it never responds the way I want and only uses the highest value in the range.

 

Thanks,

Kyle 

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Hi Kyle,

 


@Kyleab wrote:

I am using it to control the speed fo a DC motor. The range of PWM is between 1120-1920 with 1520 being stopped. I have trued tuning the controller but it never responds the way I want and only uses the highest value in the range.


PWM usually is in the range of 0…100%!

 

What exactly have you tried? Did you apply basic Ziegler-Nichols rules for determining PID gains?

How does the control loop respond? Which way do you expect it to respond?

Why don't you attach your VI(s)? We cannot debug images with LabVIEW!

Best regards,
GerdW


using LV2016/2019/2021 on Win10/11+cRIO, TestStand2016/2019
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Hi Gerd,

 

Thanks heaps for the fast respone.

 

I havent been able to understand Ziegler-Nichols approach and have been starting the process at 100 for the proportional gain and trying to alter it to get a steady oscialtion around the desired point, this was working from postion control but speed is different.

 

Good to note PWM is usually between 0-100, it may be worth me using the duty cycle then instead of trying to change the high time of the pulse.

 

I didn't attach the VIs as the layout is messy but when I am on that computer next I will attach them. I think I don't have a good understanding of the topic and this is causing me the most frustration.

 

Thanks,

Kyle

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