Every college needs lecturers like you who concentrate on the concepts rather than making us score in our exams with their crude methods! Thank you Brian!
Oh man you're telling me! I was upset how poorly that dark blue recorded but by the time I went to edit the video it was way too late. I'm not using that color again:) Thanks for the comment!
Thank you so much, Brian. I am currently studying 3rd year Mechanical Engineering, and have lost my interest in Engineering due to poor lectures. However, after seeing your videos, I am more motivated and inspired to study Engineering now, and realise how amazing Engineering is. Hopefully, you can expand your good work, make it 'big' like Khan Academy one day. Wish you all the best!
Its been almost 6 years since I started to know Control systems. Since then Whenever I need a refresh or forget sth I come back to your video... You are the best sir... Always helpful and always I learn sth new..Thanks and Good Luck
Brian, I am perfectly happy with the quick math, you have great talent to squeeze a whole lecture into my attention span. As a student I have plenty of examples to practice the math by myself. Your videos give me deeper understanding and motivation. Thank you a lot!
Thanks Brian, these lead/lag videos provided instant clarification on the topic after spending a week scratching my head in class... I'm really grateful!
Great lectures.Telling us the physical significance of the mathematics and also building our intuition. A lot of thanks Brian Douglas. And waiting for more lectures. Keep it up.
My Proff. explained it this way... A Controller (PID, PD, PI) requires an external power source or amplification where a Compensator only emulates a PID, PD, PI controller by lead, lag, or lead-lag compensation WITHOUT the need of an external power source. For example where a PI controller is used to drive steady state error to zero, a lag compensator can only emulate that, driving steady state error very close to zero but not quite there.
Great explanation! This offers a good introduction and review on what lead/lag compensators are. I tend to agree with your statement and see "controller = compensator." In that, given that the system performs in a particular way, I want give control commands that "compensates" for the undesired performance and turn it into a desired output.
Hallo Brian, thank you for your awesome intuitive illustration. I believe the last meant when you introduced the lead lag compensator the locations for the poles and zeros were reversed.
Hello! Off topic - Can you talk about state space representation if you are planning on making more videos? I heard that control engineer frequently use the state space approach to design system.
Amazing lectures. Your way of explaination is the best in this world. Could you please upload more videos so that we can learn more from a wonderful teacher.
this is something that i will also vote for!!! it's probably the most mentioned thing in my labs and tutorials, but i never got even close to understanding it completely :(
When we have a closed loop system, we are concerned about robustness, which can be determined by something called phase margin and gain margin. The higher the phase margin (measured in degrees) the more tolerant our system is to become unstable due to disturbances; therefore we are interested in modifying the phase to give us a nice "cushion" for uncertainties. Adding a phase compensator might introduce some undesired phenomena such as modifying the original bandwidth. Thanks for the video Brian
I'm taking notes from Modern Control Engineering by Katsuhiko Ogata, ed. 4 In chapter 6 section 5, Ogata doesn't really say they're trying to distinguish a controller from a compensator, but does nonetheless describe a compensator in a unique way. >In building a control system, we know that proper modification of the plant dynamics may be a simple way to meet the performance specifications.This, however, may not be possible in many practical situations because the plant may be fixed and not modifiable.Then we must adjust parameters other than those in the fixed plant. In this book, we assume that the plant is given and unalterable. >In practice, the root-locus plot of a system may indicate that the desired performance cannot be achieved just by the adjustment of gain (or some other adjustable parameter). In fact, in some cases, the system may not be stable for all values of gain (or other adjustable parameter). Then it is necessary to reshape the root loci to meet the performance specifications. >The design problems, therefore, become those of improving system performance by insertion of a compensator. Compensation of a control system is reduced to the design of a filter whose characteristics tend to compensate for the undesirable and unalterable characteristics of the plant. It's only in chapter 7 around Nyquist techniques that Ogata starts using the phrase >... controller (or compensator) ... And then by chapter 8, 'controller' alone is used exclusively concerning PD, PI, and PID. The overall trend seems to rely on two modes: 1. Ogata uses 'compensator' when your first and largest reason for modification is stability; you're compensating for inadequacies. Then they use 'controller' when stability is almost a given, and concerns are more with time-based requirements. 2. There is frequent mention of how PID controllers are modified on-site, implying that a compensator is not. Which I guess further implies that a controller has a human interface, and a compensator does not.
Hi Brian! First of all, I'd like to show you my gratitude for your channel content, it is really helping me out with my college assignments. About this topic, I have a question. In what situation a lead compensator can reduce the stability robustness of the control system?
Sir.! Your videos are amazing and helps alot in clear understandings of topics. I have a question regarding definitions of controller and compensator.. Can we say that " Controller is used to improve time response characteristics and compensator to improve frequency response characteristics" .?
Thank you very much for sharing your knowledge. I saw all your control system videos and all were very useful. Maybe state space representation lectures would be great.Thanks again and all the best!
Brian, this is truly great stuff! Thank you very much! Improvement suggestion: at 4.35 you use a very dark blue. It strained my eyes when i tried to read it against the black board. However the light blue worked perfectly :) Cheers again!
from the comments below i see that you deliver a great explanation by the examples of the real life you give, but i hope that you make more videos with mathamatical examples also because i cant really have the full picture sometimes of what you are saying , it would be awesome if you do this, i know its boring for you because you do it faster using matlab but it would be really helpful for us in our studies if you could do that. thank you in advance
Anecdotally, in my field of servo controlled hydraulic systems compensation is a passive or "dumb" action where a particular variable is acted on by a dedicated system, mechanical or electronic. Whereas a controller performs active analysis on a system and can respond to varying conditions and adjust things on the fly, and have its parameters modified to fit different conditions over time. Often controllers are used to actively adjust setpoints in compensators. For example, a pressure compensator may control the flowrate of a pump by constantly adjusting itself to maintain constant pressure at different pilot pressures. That pressure compensator is itself controlled by a proportional servo valve which can actively adjust that pressure compensation gain if desired.
active ckt is required for designing controllers pi, pd,pid . and a passive ckt for compensators lag,lead,leadlag. i guess that's the difference.. awesome video btw
You said that the pole and zero would mathematically cancel each other and it's a silly example but should we cancel them keeping in mind the state space approach and the Asymptotic stability?
To answer your question posted at 2:20 I would look at the two terms based upon intended definition: Controller - send instruction before execution, then correct execution error Compensator - send instruction after execution in order to correct execution error
I have a question, is the gain plot graph of combined lead and lag compensator is correct?? I think there should be a gain (positive or negative) for lead frequencies also.
Great stuff. Explains it very well! Do you think you could take a look at designing lag-lead compensators in the root locus, besides doing them seperately? Thanks a bunch!
As someone with zero experience in this domain, my default understanding would be: A controller is anything that controls something.. i.e. it has an output that is used as something else's input (e.g. how much power to deliver to a motor, or switch an LED on / off, or send a network packet, etc.). You can have hardware controllers and software controllers, and not all controllers are compensators. A compensator is a controller that also has a feedback input from which it reads a signal that it uses to help it make its decision about how to control. All compensators are controllers.
Controller is what converts the error into feedback. Compensator is something that changes the system to make up for design shortcomings. thats my guess
I was discussing with my friend about the difference. He said that PI controller increases noise but lead/lag compensators don't. So the use of compensator is more intuitive than the controller. Do tell me if there are more big differences. Thanks.
Douglas how did u write the transfer function as product real pole and real zero ? At approximately 5:40 in ur video How u break up the transfer function into a real zero and a real pole?
Hey mate just wondering what computer/parts and program you use as i have been locking for some hardware to write notes dureing lectures and it seems pretty good.
Thanks for posting your lectures! Are your lectures going to be focused on linear control systems only or are you planning to also describe the optimal control theory, involving calculus of variations, Pontryagin and Bellman theory?
For what I know, a compensator has the function of compensating the effects of increasing the proportional gain. Ideally, the proportional gain should be big, so that the output can follow the input, however, increasing the proportional gain too much can make the system unstable, and that is the moment where the compensator has relevance.
Hi Brian. I understood having poles and zeros reflects the stability. But I do not really sure why do we need to know the gain and phase shift and does it really matter in control system?
Hi Mr. Douglas! Your lecture videos are amazing! Are there any reference materials that you can recommend for my control systems class? Thanks in advance.
I think that a compensator is a type of controller which compensates the specifications with one or more couple of poles and zeros. Instead the controller can be just proportional, or integral and so on
It's 2019, and I know you're still saving lives.
he is 😂
Definitely!
It's 2020, and I know hes still saving lives.
And it's 2021
Its 2021 and he's helping me with my electrical engineering finals
Every college needs lecturers like you who concentrate on the concepts rather than making us score in our exams with their crude methods! Thank you Brian!
Oh man you're telling me! I was upset how poorly that dark blue recorded but by the time I went to edit the video it was way too late. I'm not using that color again:) Thanks for the comment!
It's 2023 ,and i know you're still saving lives
i passed the exam fundamental of control systems :) thank you brian douglas
Haha
My professor linked to this video from a lecture as a supplement, and I can see why. Wonderfully helpful good sir!
You are a Universal teacher and I am your Universal Students. Excellent and lucid Lectures. Hope our teachers are like you.
Oh my god. I'm a senior Aerospace Eng. bachelor. This channel is gold. Learning here more than in my univ!
It's same with my uni. I'm learning "Automation", literally.
Thank you so much, Brian. I am currently studying 3rd year Mechanical Engineering, and have lost my interest in Engineering due to poor lectures. However, after seeing your videos, I am more motivated and inspired to study Engineering now, and realise how amazing Engineering is. Hopefully, you can expand your good work, make it 'big' like Khan Academy one day. Wish you all the best!
I'm currently 2nd year master's student. You watched it 9 years ago! How's the stuff now as an engineer!?
@@mechguy118 I'm a working aerospace control engineer and I still revisit his videos. Very relevant, very useful!
I'm returning for your videos from time to time to refresh my knowledge and understand things at work. Thanks Brian!
Its been almost 6 years since I started to know Control systems. Since then Whenever I need a refresh or forget sth I come back to your video... You are the best sir... Always helpful and always I learn sth new..Thanks and Good Luck
Thank you Brian! Learned more from you in 11 minutes then 12 weeks in class! Was happy to donate to your book.
Thanks again!
Brian, I am perfectly happy with the quick math, you have great talent to squeeze a whole lecture into my attention span. As a student I have plenty of examples to practice the math by myself.
Your videos give me deeper understanding and motivation.
Thank you a lot!
As a practicing engineer that was refreshing indeed! Thanks Brian, much appreciated.
Brilliant Lecture. As Usual... Once again, you fixed the big mess I had in my head. Thanks a Million.
Thank you so much for putting all the efforts into these videos Brian. You are the best.
Thanks Brian, these lead/lag videos provided instant clarification on the topic after spending a week scratching my head in class... I'm really grateful!
Simply you are amazing, finally after relentless struggle I understood Lead/Lag compensator 😭
Great lectures.Telling us the physical significance of the mathematics and also building our intuition.
A lot of thanks Brian Douglas. And waiting for more lectures.
Keep it up.
Thanx for your videos! Its better to watch your videos than to waste time sleeping during lectures!
My Proff. explained it this way... A Controller (PID, PD, PI) requires an external power source or amplification where a Compensator only emulates a PID, PD, PI controller by lead, lag, or lead-lag compensation WITHOUT the need of an external power source. For example where a PI controller is used to drive steady state error to zero, a lag compensator can only emulate that, driving steady state error very close to zero but not quite there.
thanks
Absolutely fantastic explanation. You are a brilliant human being.
i did understand the concept when my teacher taught me...but you made it interesting.. Thank you sir!!
I always go back to your channel when I need to understand/review something in control. Thanks Brian for these truly amazing videos
Great explanation! This offers a good introduction and review on what lead/lag compensators are. I tend to agree with your statement and see "controller = compensator." In that, given that the system performs in a particular way, I want give control commands that "compensates" for the undesired performance and turn it into a desired output.
Hallo Brian, thank you for your awesome intuitive illustration. I believe the last meant when you introduced the lead lag compensator the locations for the poles and zeros were reversed.
This one really helped me recall the fundamentals of control design. Thank you so much!!!
Hello! Off topic - Can you talk about state space representation if you are planning on making more videos? I heard that control engineer frequently use the state space approach to design system.
You are phenomenal .. Why don't we have instructor like you ?!
My lord in heaven, I've just found the savior. Thank you, Brian.
You are welcome!
10:25 these questions, I'm glad you touched upon them..
It's,2023, And You are still saving lives.
Its 2021.. its still helping a lot! Thank you 😇
Learned this years ago. Needed a refresher. Very good content 👍
Amazing lectures. Your way of explaination is the best in this world. Could you please upload more videos so that we can learn more from a wonderful teacher.
this is something that i will also vote for!!! it's probably the most mentioned thing in my labs and tutorials, but i never got even close to understanding it completely :(
This guy is the plug. Seriously thank you so much, I wish I would have found these videos earlier in the semester.
When we have a closed loop system, we are concerned about robustness, which can be determined by something called phase margin and gain margin. The higher the phase margin (measured in degrees) the more tolerant our system is to become unstable due to disturbances; therefore we are interested in modifying the phase to give us a nice "cushion" for uncertainties. Adding a phase compensator might introduce some undesired phenomena such as modifying the original bandwidth. Thanks for the video Brian
thank you. finally getting a sense to what I am trying to accomplish with a lag lead comensator. saviour man
thanks, learned in 10 minutes more than I did in class.
i found why non ideal PI transfer function has wc ... really helpful video!!!
You are a genius teaching, man
Thanks for making videos like this
U r simply amazing Giving the concepts in short but clear ..
Thank you ..
Sir, you make understanding so easy. thank you so much.
Mr Douglas. You have exceptional videos. I ve looked at others. Thx
Super simplifying explanation 👌👏 thank you so much for your support to the learners
You are literally the best person ever. Thank you.
I'm taking notes from Modern Control Engineering by Katsuhiko Ogata, ed. 4
In chapter 6 section 5, Ogata doesn't really say they're trying to distinguish a controller from a compensator, but does nonetheless describe a compensator in a unique way.
>In building a control system, we know that proper modification of the plant dynamics may be a simple way to meet the performance specifications.This, however, may not be possible in many practical situations because the plant may be fixed and not modifiable.Then we must adjust parameters other than those in the fixed plant. In this book, we assume that the plant is given and unalterable.
>In practice, the root-locus plot of a system may indicate that the desired performance cannot be achieved just by the adjustment of gain (or some other adjustable parameter). In fact, in some cases, the system may not be stable for all values of gain (or other adjustable parameter). Then it is necessary to reshape the root loci to meet the performance specifications.
>The design problems, therefore, become those of improving system performance by insertion of a compensator. Compensation of a control system is reduced to the design of a filter whose characteristics tend to compensate for the undesirable and unalterable characteristics of the plant.
It's only in chapter 7 around Nyquist techniques that Ogata starts using the phrase
>... controller (or compensator) ...
And then by chapter 8, 'controller' alone is used exclusively concerning PD, PI, and PID.
The overall trend seems to rely on two modes:
1. Ogata uses 'compensator' when your first and largest reason for modification is stability; you're compensating for inadequacies. Then they use 'controller' when stability is almost a given, and concerns are more with time-based requirements.
2. There is frequent mention of how PID controllers are modified on-site, implying that a compensator is not. Which I guess further implies that a controller has a human interface, and a compensator does not.
nice
This is very useful video to explain lead/lag compensator.
thnx for the wonderful vedio @brain Douglas and all the guys who comment here also remove many confusions..thnx to them tooo
Awesome video lectures sir! You're an immense help for us to grasp the concepts and theory of control. Thank you very much
Very good presentation/explanation. Thank you a lot.
Hi Brian! First of all, I'd like to show you my gratitude for your channel content, it is really helping me out with my college assignments. About this topic, I have a question. In what situation a lead compensator can reduce the stability robustness of the control system?
Brian,your videos make me understand a lot of control system. Can you teach Mason's gain from your aspect? I will very appreciate.
I'm interested in MATLAB Control Tutorial. You have great videos. Thanks so much.
Sir.! Your videos are amazing and helps alot in clear understandings of topics.
I have a question regarding definitions of controller and compensator.. Can we say that " Controller is used to improve time response characteristics and compensator to improve frequency response characteristics" .?
Hello sir your videos are awesome sir.....
Please make videos on state space analysis also
wish my control system lecturer was like you.
it's 2024 and I am sure you are still saving many lives
Thank you very much for sharing your knowledge. I saw all your control system videos and all were very useful. Maybe state space representation lectures would be great.Thanks again and all the best!
Brian, this is truly great stuff! Thank you very much! Improvement suggestion: at 4.35 you use a very dark blue. It strained my eyes when i tried to read it against the black board. However the light blue worked perfectly :) Cheers again!
Thank you very much for clearly explaining these topics. It was very helpful.
from the comments below i see that you deliver a great explanation by the examples of the real life you give, but i hope that you make more videos with mathamatical examples also because i cant really have the full picture sometimes of what you are saying , it would be awesome if you do this, i know its boring for you because you do it faster using matlab but it would be really helpful for us in our studies if you could do that.
thank you in advance
Anecdotally, in my field of servo controlled hydraulic systems compensation is a passive or "dumb" action where a particular variable is acted on by a dedicated system, mechanical or electronic. Whereas a controller performs active analysis on a system and can respond to varying conditions and adjust things on the fly, and have its parameters modified to fit different conditions over time. Often controllers are used to actively adjust setpoints in compensators. For example, a pressure compensator may control the flowrate of a pump by constantly adjusting itself to maintain constant pressure at different pilot pressures. That pressure compensator is itself controlled by a proportional servo valve which can actively adjust that pressure compensation gain if desired.
This is seriously awesome. I wish you were my teacher.
Compensator = feedforward
Controller = feedback
active ckt is required for designing controllers pi, pd,pid . and a passive ckt for compensators lag,lead,leadlag. i guess that's the difference.. awesome video btw
Hey Brain thanks for the video it's really helpful. I think my prof said something like compensators are 'dynamic' controllers
You said that the pole and zero would mathematically cancel each other and it's a silly example but should we cancel them keeping in mind the state space approach and the Asymptotic stability?
To answer your question posted at 2:20
I would look at the two terms based upon intended definition:
Controller - send instruction before execution, then correct execution error
Compensator - send instruction after execution in order to correct execution error
🥳🤯
zajebisty jesteś gościu nie zmieniaj się
THANK YOU FOR ALL YOUR VIDEOS
Fantastic Lectures! It really helps a lot!
I have a question, is the gain plot graph of combined lead and lag compensator is correct?? I think there should be a gain (positive or negative) for lead frequencies also.
From 2022 you're helping me
Great stuff. Explains it very well! Do you think you could take a look at designing lag-lead compensators in the root locus, besides doing them seperately?
Thanks a bunch!
This guy is a genius
As someone with zero experience in this domain, my default understanding would be:
A controller is anything that controls something.. i.e. it has an output that is used as something else's input (e.g. how much power to deliver to a motor, or switch an LED on / off, or send a network packet, etc.). You can have hardware controllers and software controllers, and not all controllers are compensators.
A compensator is a controller that also has a feedback input from which it reads a signal that it uses to help it make its decision about how to control. All compensators are controllers.
Controller is what converts the error into feedback. Compensator is something that changes the system to make up for design shortcomings.
thats my guess
I was discussing with my friend about the difference. He said that PI controller increases noise but lead/lag compensators don't. So the use of compensator is more intuitive than the controller. Do tell me if there are more big differences. Thanks.
What a nice video!! Well done! I have a question: could you explain, the narrower phase lead/lag region is better or wider? thanks
Controller is for time domain response analysis and compensator is for frequency domain analysis of a system.
neatly expalined ... which software u are using in ths video ?? multicolor writing
Douglas how did u write the transfer function as product real pole and real zero ? At approximately 5:40 in ur video
How u break up the transfer function into a real zero and a real pole?
Hey mate just wondering what computer/parts and program you use as i have been locking for some hardware to write notes dureing lectures and it seems pretty good.
why does the o/p lags i/p by -90 degree? is this always happens with derivatives? or using PID only causes this lag?
Thank you so much for the video, Brian.
Thanks for posting your lectures!
Are your lectures going to be focused on linear control systems only or are you planning to also describe the optimal control theory, involving calculus of variations, Pontryagin and Bellman theory?
I had the same confusion about compensator and controller, thanks for mentioning it. btw, like your voice too
you are so amazing at this
The best video i have ever watched
These videos have been extremely helpful, thank you!
For what I know, a compensator has the function of compensating the effects of increasing the proportional gain. Ideally, the proportional gain should be big, so that the output can follow the input, however, increasing the proportional gain too much can make the system unstable, and that is the moment where the compensator has relevance.
The best explanation I've ever seen on this topic! Awesome job Brian!!!!! Thanks!
Hi Brian.
I understood having poles and zeros reflects the stability.
But I do not really sure why do we need to know the gain and phase shift and does it really matter in control system?
Hi Mr. Douglas! Your lecture videos are amazing! Are there any reference materials that you can recommend for my control systems class? Thanks in advance.
What a good Channel! Where I can find your book?
Thank you. great simplification with good knowledge.
I think that a compensator is a type of controller which compensates the specifications with one or more couple of poles and zeros. Instead the controller can be just proportional, or integral and so on
Effect of adding poles and zeros to system? eg: root locus,stability etc.
Please,Can you make a video on this topic?