This video is 7 years old, free and still provides a better understanding then the lecture content that I pay for at my institution, thank you so much.
I've been struggling these years to understand how phase and gain margin works and in a 15 min video you clearly explain it in a very dynamic way, really good content!
I am studying for my PhD qualifying exam in feedback control/linear systems and I can say this is as of yet the BEST explanation I have ever seen on this topic :) Thank you so much
This whole series is FANTASTIC!!!!! After numerous books and lectures, I did not quite get it. Control theory is starting to make sense, but more importantly starting to help my practical design efforts in power electronics.
This is hands down one of the most brilliant, simple, no bullshit videos I've ever seen. Thank you so much for this. Perfect utilisation of 13 minutes.
I've been reading papers for this so I can understand what those two are for my master's thesis and you explained it perfectly in 14 minutes. I can't thank you enough!
Man to put it simply you are a legend! You helped me understand the true meaning of a lot of things in Control Theory. You explain things that very few people on RUclips touch accurately and professors who teach the subject are mostly bothered with the maths rather than the true meaning of things. I owe you big time!
🎯 Key Takeaways for quick navigation: 00:00 📊 *Gain and Phase Margins Introduction* - Gain and phase in linear time-invariant systems: Distortion, magnitude, and phase shift explained. - Gain is the ratio of output magnitude to input magnitude; phase shift is the signal's angular shift. - Bode plots: Show system gain and phase across frequencies, crucial for understanding gain and phase margins. 03:30 🛡️ *Understanding Margins* - Margin as a safety net: Extra gain or phase before system instability. - Importance of margins in stability: Less margin can lead to instability with minor system variations. - Designing systems with built-in margin: Accounting for uncertainties and process variations. 05:49 📉 *Understanding System Instability* - Unstable systems: Characteristics involving poles or roots in the right half plane. - Assessing closed-loop stability: Designing open-loop systems and using tools like bode, root locus, and Nyquist plots. - Avoiding the -1 point: Critical for stability; staying away from the zero DB, -180 degrees phase combination. 08:06 📈 *Quantifying Margin on Bode Plots* - Analyzing gain margin: Impact on stability as gain increases or decreases. - Phase margin: Assessing phase delay for stability; its significance in system stability. - MATLAB's role in quantifying stability margins: Extracting gain and phase margin from bode plots. 10:55 🔍 *Uncertainty and Margin Sensitivity* - Impact of uncertain parameters: How a change in a single parameter can affect overall system stability. - Gain and phase margin's holistic view: Refers to margin in the entire open-loop system; focusing on specific uncertainties. - Misleading system stability: Examples where apparent stability can mislead system behavior. 13:22 🧲 *Additional Metrics for Stability* - Nyquist plot's insight: Using it to deduce system stability in relation to the -1 point. - Sensitivity metric: Evaluating the system's stability based on the proximity of curves to the -1 point. - Next steps: Teaser for exploring sensitivity in the upcoming video. Made with HARPA AI
Bioengineering student here... you sir, just saved my ass!!. There are VERY few people who can explain this subject with enthusiasm and absolute clarity. Sadly my control systems teacher is not one of them. A million thanks from Bogotá (Colombia).
Hi Brian. It's been about four years since I took any control systems lectures, but even though I work in a different branch of EE, I occasionally spend time reading up on previous topics I haven't seen since my undergraduate career. Reading through Nise's book again has been a trying and dry task, but watching these videos has shed serious clarity on the subject and I'm understanding it better than ever. Just wanted to say thank you for making these! I love a great engineering channel!
I really enjoy your videos .. when I'm tired and bored to read a book or solve problems .. I just relax and watch your videos .. God bless your soul :D
My advisor had me skip classical controls and go straight into multi-input multi-output LTI systems, so suffice to say I was very unprepared. Thanks for clearing a lot of this stuff up!
The "story " about Gain and Phase Margins I think it from the most difficult concepts...to say why and where 1 and -180 coming from and so on...Always all things are more obvious if you know the story...So imo it was so clear explanation!Good job..keep going like this...thank you!
Thanks mate, really, thank you so much. I'm an engineer and I studied that thing more than 10 years ago. These days I need the information again. After searching web for hours I was frustrated. I decided to go on youtube as a last resort and tadaaa! your video made everything clear in 10 minutes. I haven't watched the matlab part yet but I've decided to add a comment!!👍
Sadly, your videos are much better than what we get from our uni lecturer that we pay 9k a year. I understand more from 10 min of your video than from 5 lectures at uni!
Rofl 5:12 like a boss. Thanks B. Douglas for another fantastic video- your fast paced and comprehensive lessons are wonderful to watch, even if I am not really part of your target audience :)
Here to confirm this video is still helping students in 2024. When you explained how to think about the unstable transfer function going to infinity I had a massive eureka moment, thanks!
Im a South African student studying Electrical in India and its really tough and its very difficult to find proper english videos and i happen to stumble upon your channel thank you and hats off to you👍🙏
Till this day, after over a year of courses partially dealing with bode plots, I never understood the purpose of Gain and Phase Margins. THANK YOU!!! PS: You def got yourself a Like and Sub!
Best explanation. I would even say your vids are a good introduction to control. Of course having the mindset that later these things will go into much more detail, but just to grasp some overall concept of what's going on. Most lecturer's just jump way way way into the details and the CONTEXT is lost. thanks Brian.
Great video Brian, thanks for the explanation. What about a short explanation on the sign of gain margin, in particular a negative gain margin example.
Makes me want to pay more attention in class 😂. I genuinely felt like I learned something just now. And thanks to that you made me more motivated to do my work. Thank you !! :)
this guy explains better than my college teachers, all together , i keep wondering why i still pay for such a bad education!!! thanks Brian, amazing work !
Very good video to explain the bode plot, right now I study control system by myself and wanna using in the power electronics system, control theory is hard to me but this video explain the bode plot simple and easy to understand! Thx Brain~
@@UpendraYadav-mh9mm I just want to make sure about one single thing: I understand that we avoid GM = 0 dB and PH = -180° in the open-loop system in order for its close-loop configuration to be stable, but that's only true for an unitary feedback, right? Because if the feedback has, for example, a gain "K", then the resulting transfer function would be G(s) / ( 1 + K*G(s) ), therefore the close-loop system would become unstable when G(s) = -1/K, not when G(s)=-1. Am I right?
@@Marchel0522 Sir your logic seems right. But I guess you analyzed something wrong. The plot used to calculate GM and PM is constructed for open loop function ie G(s)H(s). For stability poles of closed loop(1+GH) are checked for polarity. And hence open loop plot GH is checked at(-1,0). So in my view it wouldnt make a difference if the gain is unity or not because that would be included in open loop plot GH and plot will still be checked at (-1,0). But still i'm not an expert and out of touch with control for few years, so do discuss it with someone good at it.
In under 14 minutes you explained this better than my prof in 3 lectures. I am forever indebted to you . You are the real MVP.
Exactly.....u thee boss Brian
Exactly mate.. I was going astray then suddenly I found this video.. Nice work done..!!
Not to mean that he doesn't explain well but one is able to understand this fast because you got 3 lectures before, all people seem to forget that
That is why Brian Douglas is my god. I will follow his teachings
agreeeeeeeeee
This video is 7 years old, free and still provides a better understanding then the lecture content that I pay for at my institution, thank you so much.
Everytime I search a topic in my controls class on RUclips i cross my fingers and hope there’s a Brian Douglas video lmao
Still helping people 4 years later, what a legend
Less phase and gain margin both are decrease stability or something different?
5 years later
@@harishchoudhary1441 yes, this will be still stable but the margin will be less. Will go quickly in the unstable mode for any undesired event.
6 years later.
7 years!
I've been struggling these years to understand how phase and gain margin works and in a 15 min video you clearly explain it in a very dynamic way, really good content!
I am studying for my PhD qualifying exam in feedback control/linear systems and I can say this is as of yet the BEST explanation I have ever seen on this topic :) Thank you so much
This whole series is FANTASTIC!!!!! After numerous books and lectures, I did not quite get it. Control theory is starting to make sense, but more importantly starting to help my practical design efforts in power electronics.
Brian deserves the Nobel prize for teaching!
Totally agree with you.
This is hands down one of the most brilliant, simple, no bullshit videos I've ever seen. Thank you so much for this. Perfect utilisation of 13 minutes.
I've been reading papers for this so I can understand what those two are for my master's thesis and you explained it perfectly in 14 minutes. I can't thank you enough!
4:11 wow that analogy couldn't have been more perfect.
Man to put it simply you are a legend! You helped me understand the true meaning of a lot of things in Control Theory. You explain things that very few people on RUclips touch accurately and professors who teach the subject are mostly bothered with the maths rather than the true meaning of things. I owe you big time!
I can't pass without saying "thank you". I think you are gonna save me for my System Dynamics Control exam tomorrow!
Thank You
🎯 Key Takeaways for quick navigation:
00:00 📊 *Gain and Phase Margins Introduction*
- Gain and phase in linear time-invariant systems: Distortion, magnitude, and phase shift explained.
- Gain is the ratio of output magnitude to input magnitude; phase shift is the signal's angular shift.
- Bode plots: Show system gain and phase across frequencies, crucial for understanding gain and phase margins.
03:30 🛡️ *Understanding Margins*
- Margin as a safety net: Extra gain or phase before system instability.
- Importance of margins in stability: Less margin can lead to instability with minor system variations.
- Designing systems with built-in margin: Accounting for uncertainties and process variations.
05:49 📉 *Understanding System Instability*
- Unstable systems: Characteristics involving poles or roots in the right half plane.
- Assessing closed-loop stability: Designing open-loop systems and using tools like bode, root locus, and Nyquist plots.
- Avoiding the -1 point: Critical for stability; staying away from the zero DB, -180 degrees phase combination.
08:06 📈 *Quantifying Margin on Bode Plots*
- Analyzing gain margin: Impact on stability as gain increases or decreases.
- Phase margin: Assessing phase delay for stability; its significance in system stability.
- MATLAB's role in quantifying stability margins: Extracting gain and phase margin from bode plots.
10:55 🔍 *Uncertainty and Margin Sensitivity*
- Impact of uncertain parameters: How a change in a single parameter can affect overall system stability.
- Gain and phase margin's holistic view: Refers to margin in the entire open-loop system; focusing on specific uncertainties.
- Misleading system stability: Examples where apparent stability can mislead system behavior.
13:22 🧲 *Additional Metrics for Stability*
- Nyquist plot's insight: Using it to deduce system stability in relation to the -1 point.
- Sensitivity metric: Evaluating the system's stability based on the proximity of curves to the -1 point.
- Next steps: Teaser for exploring sensitivity in the upcoming video.
Made with HARPA AI
But i dont understand how to fix this problem, Can anyone help?
Bioengineering student here... you sir, just saved my ass!!. There are VERY few people who can explain this subject with enthusiasm and absolute clarity. Sadly my control systems teacher is not one of them. A million thanks from Bogotá (Colombia).
Thank you, sir. I'm studying electrical & computer engineering and watching your videos really helped me a lot. Keep up the good work.
Hi Brian. It's been about four years since I took any control systems lectures, but even though I work in a different branch of EE, I occasionally spend time reading up on previous topics I haven't seen since my undergraduate career. Reading through Nise's book again has been a trying and dry task, but watching these videos has shed serious clarity on the subject and I'm understanding it better than ever. Just wanted to say thank you for making these! I love a great engineering channel!
You make the world a better place :)
I really agree with you...!
This explanation was incredibly clear, and helped tie up so many loose ends. Thanks so much for making this!
Wow, this Channel is the discovery of the year! What a genius way of explaining this stuff, hats off to you Brian, lovely work!
Mate you rock! I've been able to grasp all the concepts from your videos a lot better than from my professor in almost 2 months! Thanks a lot
I really enjoy your videos .. when I'm tired and bored to read a book or solve problems .. I just relax and watch your videos .. God bless your soul :D
So detail-oriented tutor! Love you so much. Thank heavens for your existence in the world!
My advisor had me skip classical controls and go straight into multi-input multi-output LTI systems, so suffice to say I was very unprepared. Thanks for clearing a lot of this stuff up!
The "story " about Gain and Phase Margins I think it from the most difficult concepts...to say why and where 1 and -180 coming from and so on...Always all things are more obvious if you know the story...So imo it was so clear explanation!Good job..keep going like this...thank you!
your explanation and drawings are a huge help to get the idea of gain and phase margin ! It is just so intuitive. thanks a lot!!
Thanks mate, really, thank you so much. I'm an engineer and I studied that thing more than 10 years ago. These days I need the information again. After searching web for hours I was frustrated. I decided to go on youtube as a last resort and tadaaa! your video made everything clear in 10 minutes. I haven't watched the matlab part yet but I've decided to add a comment!!👍
Sadly, your videos are much better than what we get from our uni lecturer that we pay 9k a year. I understand more from 10 min of your video than from 5 lectures at uni!
Rofl 5:12 like a boss. Thanks B. Douglas for another fantastic video- your fast paced and comprehensive lessons are wonderful to watch, even if I am not really part of your target audience :)
You found it! :)
what was it?
Found this series reviewing for my FE/PE exams! Exactly what I needed to get back on track.
Whatever you do, do not stop making these videos. Definitely the best video I have seen regarding the subject.
loved it man! very well explained. cheers!
Here to confirm this video is still helping students in 2024. When you explained how to think about the unstable transfer function going to infinity I had a massive eureka moment, thanks!
This teacher is literally legend
I really wish you had made this viseo last year. Your lectures makes so much more sense. Keep up the good work.
Somebody give this guy a medal
Very well explained... Been studying control system for a long time and yet this video brought the most clarity'
Im a South African student studying Electrical in India and its really tough and its very difficult to find proper english videos and i happen to stumble upon your channel thank you and hats off to you👍🙏
one of the best videos I have ever watched to understand Bode plot
Wow! That's f***ing brilliant! Gonna binge watch your playlist before my exam in a week.
Amazing work mate!
Thanks again Brian! It's not many people can make you laugh while clearly explaining control theory!
I could not find a better explanation anywhere on the internet!
This video is simply the best of the videos I have watched on this topic. Thank you very much
AWESOME!!! that is absolutely the best thing i ve ever found as a teaching video!!
Explained it to the optimum level.... Good job. Thanks a lot
You are very thorough in your videos, thank you so much!
Till this day, after over a year of courses partially dealing with bode plots, I never understood the purpose of Gain and Phase Margins. THANK YOU!!!
PS: You def got yourself a Like and Sub!
Best explanation. I would even say your vids are a good introduction to control. Of course having the mindset that later these things will go into much more detail, but just to grasp some overall concept of what's going on. Most lecturer's just jump way way way into the details and the CONTEXT is lost. thanks Brian.
Great video Brian, thanks for the explanation. What about a short explanation on the sign of gain margin, in particular a negative gain margin example.
Awesome work! The explanation, length, speed, pronunciation... everything is perfect! Thanks a lot!
Simply Wow!! That feeling when you understand it so good!!
Dear Brian, your tutorials are all excellent!
This guy’s free video>>> my sleepy academics control theory professor who simply reads aloud his power point slides and calls it a day
this is so far the best explanation to this topic. Thanks!!!!
commend the one true savior of all my control courses
You exactly explained
In just 13 min .
Thanks for lecture .
you are a genius at tying these concepts together ty ty ty ty
Wow. NOW I understand this. I will be watching the other videos also. Thanks for this fantastic lecture.
Great video. Cleared so much ambiguity in this topic.
Super awesome explanation, saving me from confusion. Thanks Brian!
Its people like you who inspire me!!
you sir are the only reason I passed control systems course T_T THANK YOU
This was much much better than what I learned during our lectures. Thanks a lot
Totally relieved because tomorrow saturday i'll have my processs control exam for chemeng and my lecture didnt explain those as well as you did :)))
your videos are helping me very much in understanding control systems. This is really an intuitive approach. Thanks a lot sir!
Thanks for the simplest and awesome explanation of a complex topic 🙏🙏🙏
Some are born to teach ,you are one of them👌👌
man you are a life saver. i have been watching a lot of your videos and the all have been helpfull to me. big up man
This video is so revealing for the concept of why use of bode diagrams - I LIKED IT - ...… thanks a lot Brian =D
you are my father
Makes me want to pay more attention in class 😂. I genuinely felt like I learned something just now. And thanks to that you made me more motivated to do my work. Thank you !! :)
this guy explains better than my college teachers, all together , i keep wondering why i still pay for such a bad education!!!
thanks Brian, amazing work !
Such a wonderful explanation
No words to express my happiness
Thank You
Awesome explanation. It cleared so many doubts. Couldn't have asked more on this topic with Matlab demonstrations. Thanks a lot again.
Woww,I have never found such an amazing video on youtube ,so great illustrations ,please help us by keeping it up
Great videos Brian, I watched them throughout a control systems course and they really helped with intuitively understanding the topics.
Very good video to explain the bode plot, right now I study control system by myself and wanna using in the power electronics system, control theory is hard to me but this video explain the bode plot simple and easy to understand! Thx Brain~
6:58 AHA!
Levi Schmitz You made me chuckle thank you ^^
I was waiting for this video! Such an important topic! Thanks Brian!
Just want to let you know that you've inspired people like me to be interested in engineering
Can't go without leaving a comment...Good videos bro..Never heard an explanation like this...❤️😍
Man. Your concepts are crystal clear. You nailed it sir. 👍🏻
Bode is nice, but it can provide false answers for non-minimum phase systems. Nyquist is ALWAYS reliable.
Thank you so much for this! So much more clear than my professor's lecture!
Brief and to the point. Very helpful. Thank you for this amazing short lecture.
thanks for taking painstaking effort to put this together!
Much better than any of my lecturers
Thank you so much from the S.Korea!
This explanation was very good. Thanks for sharing.
Brian, you're better than any Control systems professor at Imperial College London!
this was excellent. exactly the level of detail I needed. Thank you!
As others do, I learn the concept more quickly than unv. lectures.
I love this so much. Although my teacher is smart and cool, you are weigh better. Appreciate your dedication to create such contents.
Your explanations are amazing!! Please keep it up!!
Thanks a lot Brian,I got too much than I ever expected abt this topic.....now,it's interesting...
YES! Thank you Brian. This is exactly what I have been trying to figure out for a long time.
This video is VERY helpful. Thank you for such a well-made production!
I like your video. They are clear and effective. Thank you and please make more.
Great job man! I've been trying to figure out for a week why we want to avoid GM = 0 and PH = 180. Thanks!!!
Aj Miller because that is the case for critical stability. If you have any questions further feel free to ask.
@@UpendraYadav-mh9mm I just want to make sure about one single thing: I understand that we avoid GM = 0 dB and PH = -180° in the open-loop system in order for its close-loop configuration to be stable, but that's only true for an unitary feedback, right? Because if the feedback has, for example, a gain "K", then the resulting transfer function would be G(s) / ( 1 + K*G(s) ), therefore the close-loop system would become unstable when G(s) = -1/K, not when G(s)=-1. Am I right?
@@Marchel0522 Sir your logic seems right. But I guess you analyzed something wrong.
The plot used to calculate GM and PM is constructed for open loop function ie G(s)H(s).
For stability poles of closed loop(1+GH) are checked for polarity. And hence open loop plot GH is checked at(-1,0).
So in my view it wouldnt make a difference if the gain is unity or not because that would be included in open loop plot GH and plot will still be checked at (-1,0).
But still i'm not an expert and out of touch with control for few years, so do discuss it with someone good at it.
I gained quite a lot of understanding here! Thankyou!