Practical Implementation Issues with a PID Controller
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- Опубліковано 30 чер 2024
- PID controllers are some of the most common and effective controllers in use today. Despite their relative simplicity, there are several issues that you should be aware of if you plan on using a PID controller. In this video we discuss some of these issues such as derivative noise and integrator wind-up. We also present several solutions to these problems and discuss their integration into a larger control architecture.
Topics and timestamps:
0:00 - Introduction
2:57 - Derivative issues
3:52 - Noncausal issues
9:20 - Noise issues
48:03 - Integrator issues
1:10:04 - Mass spring damper example
1:18:10 - Aerosonde example
1:35:30 - Prefilter
1:50:24 - Anti-windup schemes
All Control Theory videos in a single playlist ( • Control Theory )
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Select pictures and graphics courtesy of:
“Aerosonde Robotic Airplane Completes Historic Trans-Atlantic Flight”, Rob Harrill, August 21, 1998
“Laima: The First Atlantic Crossing by Unmanned Aircraft”, Tad McGeer, February 25, 1999.
You can support this channel via Patreon at / christopherwlum . Thank you for your help!
These videos are so high quality. I really like the extended, classroom-lecture-style videos. There are a lot of short 10 minute lectures on UA-cam, and many of them are quite good but nothing beats in-depth lectures when you really want to learn a topic. Thanks!
Hi Ignatius,
Thanks for the kind words, I'm glad you enjoyed the video. If the find the these videos to be helpful, I hope you'll consider supporting the channel via Patreon at www.patreon.com/christopherwlum. Given your interest in this topic, I'd love to have you a as a Patron as I'm able to talk/interact personally with all Patrons. I'm also able to answer questions on Patreon in case you ever want to talk about any of the videos. Thanks for watching!
-Chris
Hey Christopher, I'm a control engineer and I must say it was an amazing lecture, thanks!
Thanks for the kind words, I'm glad you enjoyed the video. If the find the these videos to be helpful, I hope you'll consider supporting the channel via Patreon at www.patreon.com/christopherwlum. Given your interest in this topic, I'd love to have you a as a Patron as I'm able to talk/interact personally with all Patrons. Thanks for watching!
Hey professor. i couldn't thank more for your videos. Paying in millions at university but no one is there to teach like you and that too at free of cost. Once again thank you so much.LOVE FROM PAKISTAN
Hi,
Thanks for the kind words, I'm glad you enjoyed the video. If the find the these videos to be helpful, I hope you'll consider supporting the channel via Patreon at www.patreon.com/christopherwlum. Given your interest in this topic, I'd love to have you a as a Patron as I'm able to talk/interact personally with all Patrons. Thanks for watching!
-Chris
@@ChristopherLum i would but the card i am using is not accepting any international transaction. However i have forwarded your channel to all of my control system friends
@@idreeskhan5129 No worries, thanks for sharing the channel and for watching, have a good day!
As always, great video! I'm happy to be a patron. I thought I would comment that there is another reason to evaluate the integral in PID in the order Ki then the sum (discrete) / integral (continuous): (error -> Ki -> 1/s -> output). When changing the Ki coefficient, if you have Ki term preceding the sum, then any change to the Ki term will change the rate that the total integral term "changes". There will be no step discontinuities. If the sum precedes the Ki term, a change in the Ki term will result in a step change in the total integral term. This is almost never desired. When would you change the Ki term on a "hot" system? 1) When tuning on a test stand and 2) gain scheduling 3) when you switch your control law "off" temporarily. In addition, the Aerosonde example is a great example of how the whole problem could have been avoided by using this scheme. When switching from PID control to manual control, the Ki term could have been set to 0. If the Ki term precedes the integral sum, then the integral sum wouldn't build up and it's super easy to code this up (this does not eliminate the reason to limit the integral sum). Of course, this avoids the issue that a live control loop should never be left executing when not "hooked up" to anything. Leaving he forward path "broken" is the ultimate in non-linear control! :). Many thanks to Chris for making a video with such meaty topics!
Great comment and great observations, thanks for sharing!
Thanks for uploading these videos, it's amazing!!
I'm glad you enjoy them. Thanks for watching!
AE511: Great lecture Chris! I liked the story about the Aerosonde.
I can't describe how great this video is ... thank you sir for Sharing your knowledge with us i am very glad
Mohamed,
Thanks for the kind words. If you have questions or would like to request a video, please consider supporting the channel via Patreon at www.patreon.com/christopherwlum. I interact personally with Patrons at all levels. Thanks for watching!
thanks for a great video sir...in India we use word "GURU" for great teacher....and you are guru!! thanx a lot guruji
DR RORPOPOR HERBAL on UA-cam changed my entire life with his herbal medicine. I appreciate you sir, for taken away my PID 🌿🌿
Great work. I truly enjoyed this video. Thank you.
I don't know how to thank you. You are one of the best teacher.
[AE 511]
This lecture helped me understand the integrator part of the controller much better. The accumulation of error or wind up is much more clear.
Great, hopefully this addresses your comments on the integrator state. Keep me posted on how the other videos go.
hi Christopher ... Started following your lectures on control .... They are amazing and simple to understand
This is amazing, one of the best channels on UA-cam
Potatorino,
Thanks for the kind words. If you have questions or would like to request a video, please consider supporting the channel via Patreon at www.patreon.com/christopherwlum. I interact personally with Patrons at all levels. Thanks for watching!
Hi Chris, I loved the Aerosonde story and the way you tied it to the material. I've been a controls engineer for a while and I love the way you present the subject. I like how you highlight the physical meaning of theory-based insights, like the delay and disproportionate noise amplification inherent in the derivative or the subtlety the integral no longer commutes after saturation. Something I'd like to see is your take on how to go about discretizing a continuous-time design for the purpose of then implementing it on digital hardware. Considerations on forward/backward Euler vs Tustin vs others, etc. Keep it up!
Hi,
Thanks for the kind words, I'm glad you enjoyed the video. I find it is always fun to try and include stories if possible. If the find the these videos to be helpful, I hope you'll consider supporting the channel via Patreon at www.patreon.com/christopherwlum. Given your interest in this topic, I'd love to have you a as a Patron as I'm able to talk/interact personally with all Patrons. Thanks for watching!
-Chris
@@ChristopherLum I think I became a supporter on Patreon moments after leaving this message. Great work!
@@thevaf2825 Thanks, I very much appreciate the support. Please feel free to message me on Patreon as I'm able to be much more responsive on that platform. Thanks again!
Stuck with the controller of the Atomic Force Microscopy device and this video is much better to understand the PI controller. I hope to solve the problem soon. Thanks, Professor for such amazing videos on control theory along with Simulink
Hi,
Thanks for the kind words, I'm glad you enjoyed the video. If you find these videos helpful, I hope you'll consider supporting the channel via Patreon at www.patreon.com/christopherwlum or via the 'Thanks' button underneath the video. Given your interest in this topic, I'd love to have you a as a Patron as I'm able to talk/interact personally with all Patrons. I can also answer any questions, provide code, notes, downloads, etc. on Patreon. Thanks for watching!
-Chris
Brilliant lecture.
Please upload "Introduction to PID controller " video sir
Once more, another great vedio. Thanks a lot.
Ali,
Thanks for the kind words. If you have questions or would like to request a video, please consider supporting the channel via Patreon at www.patreon.com/christopherwlum. I interact personally with Patrons at all levels. Thanks for watching!
Thank you Christopher it is necessary lecture
Отличный урок, спасибо!
In case it is helpful, here are all my Control Theory videos in a single playlist ua-cam.com/play/PLxdnSsBqCrrF9KOQRB9ByfB0EUMwnLO9o.html. You can support this channel via Patreon at www.patreon.com/christopherwlum. Please let me know what you think in the comments. Thanks for watching!
Today is my exam on control theory paper thank youuu ❤
Your way of teaching is fantastic and very step-by-step. Let me request you to make a video on "Quadrotor control". PID is a linear controller but Quadrotor is a non-linear system. We know that linearization works in a limited domain. But if we control it via non-linear technique, its very good. Can you upload a video in which you 1st do modeling of a Quadrotor and then control that with a non-linear technique in MATLAB?
Hi,
Thanks for reaching out. If you have questions or would like to request a video, I hope you'll consider supporting the channel via Patreon at www.patreon.com/christopherwlum. I'd love to have you as a Patron as I'm able to talk/interact personally with Patrons. Thanks for watching!
-Chris
AE511: This lecture going insane rn! 😎😎😎
Re-watching today because it was so good👌🏂
Great video sir
great lecture.....Thanks....keep doing......
Hi Aakash,
Thanks for the kind words, I'm glad you enjoyed the video. If you find these videos helpful, I hope you'll consider supporting the channel via Patreon at www.patreon.com/christopherwlum or via the 'Thanks' button underneath the video. Given your interest in this topic, I'd love to have you a as a Patron as I'm able to talk/interact personally with all Patrons. Thanks for watching!
-Chris
This is amazing
DR RORPOPOR HERBAL on UA-cam changed my entire life with his herbal medicine. I appreciate you sir, for taken away my PID 🌿🌿
Hi Chris, thank you so much for these videos. Not sure if you know about Signal Viewer and how easy it is to use that (for viewing multiple signals together, separate, or whatever) instead of the scope blocks. All you'd need is just an output port for each signal you're trying to add to the Viewer. I discovered about this a few months back and it has made my life so much easier.
DR RORPOPOR HERBAL on UA-cam changed my entire life with his herbal medicine. I appreciate you sir, for taken away my PID 🌿🌿
Great video
Hi Zhang,
I noticed you've been watching several of the videos on the channel. Thanks for watching and I hope you enjoyed the videos. Since you seem interested in engineering and control topics, I hope you'll consider supporting the channel via Patreon at www.patreon.com/christopherwlum . I'd love to have you as a Patron as I'm able to talk/interact personally with Patrons. I hope to hear from you on Patreon or on another video on UA-cam!
-Chris
Thanks!
Hi Eric,
First let me say thank you for your generous support of the channel, it is very much appreciated!
Do you have any particular interests in terms of videos or topics? I try to prioritize request made by interested parties as much as possible as I plan future videos.
If you are interested, I interact personally with all Patreon members at www.patreon.com/christopherwlum. Given your interest in the topic, I'd love to have you as a Patron.
In any event, I want to again say thank you for your contribution and for supporting the channel. I hope to hear from you at a future UA-cam video or on Patreon!
-Chris
Hi Chris, thank you so much for these videos. Would you please share the matlab/simulink code for this video? I tried to make matlab/simulink code based on this video and previous, but designing the guidance module is not presented here.
when comparing two plots, u can put the arrows to same scope for ease of visualization, but ig u have figured it out by now, considering this video is 2 years old. Thank you for making such a crystal clear video
Hi Christopher,
Thanks for the video, I really enjoyed it.
I want to know why we don't consider a lead-lag compensator instead of a PID to avoid noise amplification problem for derivative and integral windup problem for the integrator. I mean does PID have a spectacular benefit over lead-lag compensator that makes it the main option?
You know you are speaking fast when you almost loose your breath while speaking
AE511: This helps clear up some of the adverse behavior I was seeing in my use of the integrator in the previous homework. Is the decision of which nonlinear integrator fix (solutions 2-4) to use largely made via trial-and-error?
Yes, this takes some experience/intuition. Because some are nonlinear fixes, we don't have good tools to design for them yet.
Do you remember what signal you were using for the error term in the example you gave of a limited integral state vs limited output? When I set up a similar system and used a square wave as the input signal, I got the same output when limiting the integral block (what you called limiting the state of the integral) as when I put a saturation block on the output of the integrator. I think I'd understand the concept better if I knew what the input signal was, as I presume this is only an issue for certain types of functions/signals.
Hi Ignatius,
Thanks for reaching out, I'm glad you enjoyed the video. Unfortunately I'm unable to respond to questions on UA-cam due to the sheer volume of inquiries that I receive. That being said, I hope you'll consider supporting the channel via Patreon at www.patreon.com/christopherwlum or via the 'Thanks' button underneath the video as I'll be able to answer questions there. Given your interest in the topic, I'd love to have you as a Patron as I'm able to talk/interact personally with Patrons. Thanks for watching!
-Chris
AE511: It seems like the integrator is required to guarantee no steady state error but also has the most tendency to make the controller behave adversely.
As Ben Parker said, "with great power comes great responsibility"
AE511: Is there an analog to a pre filter and damping ratio? It seems like decreasing the coefficients you're effectively increasing the damping ratio of the system.
I can't find the introduction to PID video anywhere on your channel. Is it still available?
Sir, do you have any idea about the implementation of Nonlinear controllers with analog circuits? As for PID, we can construct analog PID controllers by resistors, capacitors, and opamp, because they involve simple calculus, but nonlinear controllers involve very difficult and complex mathematics, so how to implement these controllers in real-world systems?
AE 511: Looking at the list of anti-windup solutions, I had made the assumption that solution 2 of disabling the integrator would be the easiest approach. I don't understand how having the "if statement" on the integrator would make the system non-linear... How would the system become non-linear?
An if statement is a nonlinear operation as it fails super position
Would there be any risk to applying prefilters to only the I and D terms, but leaving the P term unfiltered?
Hi Andrew,
Thanks for reaching out, I'm glad you enjoyed the video. Unfortunately I'm unable to respond to questions on UA-cam due to the sheer volume of inquiries that I receive. That being said, I hope you'll consider supporting the channel via Patreon at www.patreon.com/christopherwlum or via the 'Thanks' button underneath the video as I'll be able to answer questions there. Given your interest in the topic, I'd love to have you as a Patron as I'm able to talk/interact personally with Patrons. Thanks for watching!
-Chris
Integrator does not have any accumulation until t-w, in option 3.
is it fault？
Sir pls about mathematical representation of rotary inverted pendulum pls pls
Hi Fraol,
Thanks for reaching out. If you have questions or would like to request a video, I hope you'll consider supporting the channel via Patreon at www.patreon.com/christopherwlum or via the 'Thanks' button underneath the video. I'd love to have you as a Patron as I'm able to talk/interact personally with Patrons. Thanks for watching!
-Chris
Does anyone know of a pid controller that will vary the voltage output rather than just cycle on and off. Thanks
DR RORPOPOR HERBAL on UA-cam changed my entire life with his herbal medicine. I appreciate you sir, for taken away my PID 🌿🌿
how can get your full lecture
DR RORPOPOR HERBAL on UA-cam changed my entire life with his herbal medicine. I appreciate you sir, for taken away my PID 🌿🌿
Good stuff sir, but pardon me. Audio is hard to follow, it sounds like your yelling even thou I have my sound at minimum. Maybe you have too much of gain or normalization. I guess you have some reason for over processing this audio. Thank you for great videos.
Thanks for the feedback, I'll take a look at the audio processing. I'm glad you enjoyed the video. If the find the these videos to be helpful, I hope you'll consider supporting the channel via Patreon at www.patreon.com/christopherwlum. Given your interest in this topic, I'd love to have you a as a Patron as I'm able to talk/interact personally with all Patrons. Thanks for watching!
DR RORPOPOR HERBAL on UA-cam changed my entire life with his herbal medicine. I appreciate you sir, for taken away my PID 🌿🌿
The problem I have with these videos is that too much time is wasted drawing or wiring the equations. They should be done ahead of time. The information density is low. Most 'noise" is not really noise. It is due to low resolution feedback. The feedback signals are "quantized" by the resolution of the feed back. A fast sample time helps but feedback resolution is more important. I didn't like the statement at the end about poles and zeros don't apply to a modified PID. The derivative low pass filter adds poles and the integrator pole is valid as long as the controller doesn't go into saturation. If the system does go into saturation then the control is basically open loop anyway.
I don't know how to thank you. You are one of the best teacher.
Hi Ajeet,
Thanks for the kind words, I'm glad you enjoyed the video. If you find these videos helpful, I hope you'll consider supporting the channel via Patreon at www.patreon.com/christopherwlum or via the 'Thanks' button underneath the video. Given your interest in this topic, I'd love to have you a as a Patron as I'm able to talk/interact personally with all Patrons. I can also answer any questions, provide code, notes, downloads, etc. on Patreon. Thanks for watching!
-Chris