The Root Locus Method - Introduction

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  • Опубліковано 25 гру 2024

КОМЕНТАРІ • 499

  • @Paddydothrock
    @Paddydothrock 9 років тому +1008

    I never thought I'd see the day when someone could produce a youtube tutorial video which progresses in a logical way, makes sense throughout, doesn't have a highly irritating voice, uses a decent microphone and doesn't constantly fumble with it, stays on topic and has not just legible but actually impressively neat writing..
    Thankyou so much, yours are the best tutorial videos I've seen.
    Please consider giving some lessons to Kahn Academy.

    • @hyderali4351
      @hyderali4351 7 років тому +6

      can't agree more !

    • @vuongngo2181
      @vuongngo2181 6 років тому +3

      You are very detailed and thorough. Keep it up!!

    • @mrsblackviper
      @mrsblackviper 3 роки тому

      well it take a lot of effort to achive that.

  • @ianhanley1213
    @ianhanley1213 5 років тому +75

    I am a fifth year Aeronautical engineering student, currently using root locus to design aircraft flight control systems. This fifteen minute video is a more complete, effective and absorbable explanation than I have been given throughout my degree.

    • @fac7orcosplay
      @fac7orcosplay Рік тому +5

      Currently studying Electrical Engineering, I have to pass the final exam of Automatic Control, this videos were much more helpful than the entire course

  • @neroskywalker9183
    @neroskywalker9183 8 років тому +621

    I've learned more of the basis of root locus in this video than in my whole course in the university.

    • @keval761
      @keval761 7 років тому +2

      NeroSkywalker which uni? xD

    • @batman_1st
      @batman_1st 7 років тому +5

      National university of singapore

    • @TheTeladras
      @TheTeladras 7 років тому +4

      Could it be that u did not listen during the courses? :d

    • @Nazirm7
      @Nazirm7 7 років тому +31

      Yeah probably didn't because his professor couldn't explain for shit like mine or didn't do any examples

    • @julius8631
      @julius8631 7 років тому +1

      Same here

  • @BrianBDouglas
    @BrianBDouglas  12 років тому +58

    Hello, I briefly cover that in my video called Stability of Closed Loop Control Systems starting at around 6 minutes. The even faster answer though is that the time response of a pole is e^st, where s is the location of the pole in the s-domain. If s is negative (left half plane) then as time get's larger e^st gets smaller (stable). If s is positive, then e^st gets larger as time increases. No matter how many poles you have, it only takes 1 unstable pole to drive the system to infinity.

  • @sagasa456
    @sagasa456 Місяць тому +1

    Wow as someone who's currently struggling with a flight controls class with a non native speaking professor and no controls theory background, this is GOLD ! Thanks so much

  • @iAMCobalus
    @iAMCobalus 2 роки тому +1

    You are literally the GOAT. You broke down a concept and explained it so well with amazing visualizations. This video deserves an award!

  • @NTNscrub
    @NTNscrub Рік тому +2

    You helped me understand the purpose of a root locus in 5 minutes better than my prof did in two lectures. Thank you.

  • @Lolwutfordawin
    @Lolwutfordawin 3 роки тому +6

    my uni has done an awful job at online classes, these series of yours are a life saver! so wonderfully explained!

  • @dinmukhamedzardykhan5815
    @dinmukhamedzardykhan5815 10 років тому +19

    I am subscribed to you forever.. A lecture have never been so clear..

  • @anantchopra1663
    @anantchopra1663 5 років тому +5

    One of THE best videos I've ever seen on Control Systems. I learnt far more from your video than my control systems course at my university. Amazing explanation with wonderful insights! Hats off to you for producing such great work!

  • @shovon9412
    @shovon9412 4 роки тому

    This is a gold mine for any control engineer who is still in the learning phase or even for those who is just revising man

  • @dorsaghaemi
    @dorsaghaemi 8 років тому +1

    Thanks Brian. After 12 years in Control Engineering, This is the first time I have this level of understanding, which you provide.

  • @abdulazizsalman6197
    @abdulazizsalman6197 4 роки тому

    i got tears on my eyes when i watched your explanation, it is the greatest lesson i have heard in entire my life even though i am in a university with among of useless lecturers , thank you so much

  • @myonlynick
    @myonlynick 5 років тому +5

    0:00 up to 6:30 is PACKED with a load of insight info!

  • @bobseagull7600
    @bobseagull7600 5 років тому +1

    It's interesting to see just how much people appreciate good quality videos. Nearly a million views for the nerdiest content on UA-cam. Congrats and thank you for your work!

  • @aminijooni
    @aminijooni 8 років тому +27

    you're my hero Brian. well explained and super easy to understand. thank you

  • @kdmq
    @kdmq 6 років тому +83

    My professor never explained everything up to 6:30 and just explained root locus and threw me off for half the semester. I should have skipped more classes!

    • @rubenayla
      @rubenayla 4 роки тому +8

      That's the conclusion I come to everytime I go to class.

  • @Rmkrh
    @Rmkrh 3 роки тому

    Thank you Brian for these videos. I am feeling like I am reborn after watching this. 10 mins of your video has taught me more than what 6 months of studies in my university have.

  • @DhirenDave-v4g
    @DhirenDave-v4g 11 місяців тому

    The way you have explained the concept with very illustrative examples is fantastic. You are doing a great service to the engineering community by this effort. Please keep it up. Thank you.

  • @ChrisjayH1
    @ChrisjayH1 11 років тому +3

    I think my entire class is watching your videos. Thank you so much for these.

    • @darrenp83
      @darrenp83 11 років тому

      Yup! We are all watching these videos!

    • @nemesis3255
      @nemesis3255 11 років тому

      Darren P And I had to find out all by myself...

  • @yakovmarkov
    @yakovmarkov 10 років тому +77

    Hi Brian, thank you for the lectures, I really appreciate your job.
    I'd like know if it is possible you make a PDF file of your video lectures allowing us check the notes later.

  • @gang57
    @gang57 9 років тому

    i must post this, i just came back from my exam "control systems" today. during my preparations i used all your videos about the root locus and the nyquist. I must say, thank you very very much Brain, because of you i managed to get the proper insight i needed. your techniek is awesome, good animated and keeps the interest locked on target! thanks many times bro

  • @imafirinmalaser
    @imafirinmalaser 11 років тому +1

    Brian, you are amazing. Honestly. As an undergrad control system engineer, I am indebted to you!

  • @sudmudmud357
    @sudmudmud357 4 роки тому +1

    Not everyone got the skills to teach and nail it right there, I feel like I can obtain a degree just attending UA-cam videos, your videos are one of the reasons. Keep up the good work .

  • @sowasvonkeinplan
    @sowasvonkeinplan 5 років тому +8

    It's wierd... I've been attending 3 lectures on system's theory and control theory during my university studies several years ago and I have the impression that the first 5 minutes of your video tought me a lot more about one of the most useful methods frequently used in control theory than all of the lectures together. Maybe my point of view is a little bit biased as there's a lot of previous knowledge so everything seems total intuitive. Anyway, I wished my professors had been as talented as you explaining and presenting stuff like that. Great video.

  • @Bahloola17
    @Bahloola17 10 років тому +6

    amazing is the way you explained it!!! I read about root locus 100 times but never understood the logic behind it... now it makes sense :)

  • @deekshas3936
    @deekshas3936 Рік тому

    This is such a great video oh my god. Our teacher didn't even tell us what k is supposed to be. We just solve problems mindlessly. But you helped me to understand the meaning and the real use of the root locus. It was so intuitive that something just clicked in my brain. Also along the way, your explanation of the s plane helped me to fill in some gaps in understanding. The video was very engaging throughout. Thank you so so much!!!

  • @MusicGameFinatic999
    @MusicGameFinatic999 4 роки тому

    Dude you are the MAN. I'm about to be able to pass my control system design course thanks to these videos. Thank you so much.

  • @nikosips
    @nikosips 6 років тому

    I have no words.. thumbs up from an undergrad of electrical and computer engineering! The intuition you give on this subject is amazing and really helpful . Keep the videos coming !!

  • @juliajordan5023
    @juliajordan5023 11 років тому +3

    You are awesome! Really great examples, practical applications, the graphs help a visual learner such as myself, and you draw awesome pictures and comics! Keep up the good work! I am so excited about control theory!

  • @chrisp7255
    @chrisp7255 8 років тому +2

    I am using this to study for a final right now, and I am so mad I didn't discover this earlier. This would have cleared up an entire semester's worth of confusion. Thanks for the explanation Brian, this is really well done.

  • @BrianBDouglas
    @BrianBDouglas  11 років тому

    Hey James, no problem. The transfer function is 1/(s^2 + 1.5s + k). For such a simple transfer this is the easiest way. Put the den. in standard form which would be s^2+1.5s+k = s^2+2*z*w*s+w^2. When k = 1.1 then it's easy to solve for the damping ratio. w = sqrt(1.1) =1.049. Then z = 1.5/(2*1.049) = 0.715. Of course the root locus is a good way to visualize how the damping ratio changes with k. On the diagram zeta = sin(angle between pole to origin and the vertical axis).

  • @PunmasterSTP
    @PunmasterSTP 2 роки тому +1

    I'm so glad I came across your channel, because your videos are so superb. I'm sure other commenters have already given much praise, and so long ago, in more eloquent ways, so I'll just say "Thank you!"

    • @prateekmuthiahnitap8447
      @prateekmuthiahnitap8447 2 роки тому +1

      Hi samter from Neso academy comment section ( ͡° ͜ʖ ͡°)

    • @PunmasterSTP
      @PunmasterSTP 2 роки тому +1

      @@prateekmuthiahnitap8447 Hello back! How are you doing? Also, are you studying for the JEE or another test? As for myself, I tutor in electrical engineering a bit, so I try to stay sharp...

    • @prateekmuthiahnitap8447
      @prateekmuthiahnitap8447 2 роки тому +1

      @@PunmasterSTP I'm doing great! Well atleast for now...
      Wish me luck for my currently ongoing college exams ^^

    • @PunmasterSTP
      @PunmasterSTP 2 роки тому +1

      @@prateekmuthiahnitap8447 I'm glad to hear it, and best of luck on your exams!

  • @Pyrohawk
    @Pyrohawk 4 роки тому

    Your tutorials are amazing. You've given a gift to humanity.

  • @Plenty_for_Twenty
    @Plenty_for_Twenty 2 роки тому +1

    UA-cam University prevails again. I was not entirely grasping RL from my professor and the textbook. Just kind of head down and mathing into the unknown. Your video placed a ton of perspective into my study. Thank you Brian Douglas 🍻

  • @davoodseify3624
    @davoodseify3624 5 років тому +11

    Man your explanation was extraordinary. I’ve learned so much here than anywhere else. It helps me so much. Thank you🙂🙏

  • @magyarandrastamas2485
    @magyarandrastamas2485 9 років тому +1

    If only 1/10 of the teachers had such a huge enthusiasm to make the students got the curicullum then people would love to go to school.
    Good teacher equals knowledge + fedback enthusiastic repetition till the understood lecture equals the determined level. :)
    Well done Brian!

  • @Carrierski
    @Carrierski 9 років тому

    This is literally the best explanation i have EVER seen in my life. Very clear, the speed is perfect and answers all important questions. Instant sub.

  • @fawazmohsin2287
    @fawazmohsin2287 4 роки тому

    This series is the best way to learn about root loci

  • @matthewoliver88
    @matthewoliver88 5 років тому

    I have a test tomorrow and this is the first video that i clicked on. You're my hero

  • @greersimpson
    @greersimpson 11 років тому

    Thank you so much you I just watched all of your lectures in one sitting and it literally just clicked. Your the man, keep it up!

  • @nalostta
    @nalostta 6 років тому

    man,you explained not just the technique ,but also the right questions that should go through ones mind while doing this...amazing!!!

  • @RobBabu
    @RobBabu 6 років тому +5

    Great Video Brian! You're a huge help to all of us struggling with control systems (aka all of us) :)

  • @19hashan93
    @19hashan93 11 років тому +1

    THANK YOU SO VERY MUCH DR. BRIAN!! In a little over 10 minutes, you managed to teach a topic that I couldnt understand in 2 hours at class. You are extremely awesome for uploading these. We are eternally grateful! Liked and Subscribed! Its also amazing how you linked this to a real world engineering problem so well. It reminds one that engineering is not just numbers and maths but directly mirrors what goes on in reality. (btw, the "we messed up" cartoon was a brilliant idea!)

  • @Jkemp-yq4qq
    @Jkemp-yq4qq 4 роки тому

    Absolutely fabulous! I love the practical application. Very helpful You taught me more in 13 minutes than I learned in 4 hours of lecture.

  • @MrRawnik
    @MrRawnik 9 років тому +33

    brian you are awesome. like your methodology.

  • @LuigidBlackhouse
    @LuigidBlackhouse 11 років тому

    Thank you, you saved my live (or at least my grade). This video (and the other two) helped me catch up some lectures I missed due to an illness.

  • @ShahzadHassanBangash
    @ShahzadHassanBangash 8 років тому

    great work sir keep up the good work our society need people like you .

  • @sullivan3503
    @sullivan3503 2 роки тому +5

    At 7:30, you mention that natural frequency requirements dictate that the pole must lie inside a horizontal band. However, this would correspond to limiting the imaginary part of the mode. The natural frequency corresponds to the norm of the pole, which would mean the pole must lie inside or outside of a certain circle.

  • @BrianBDouglas
    @BrianBDouglas  10 років тому +28

    viraj shelke and Suraj more, It's hard to explain in writing but I'll try. Start with the root locus form of the transfer function: G(s)/(1+K*G(s)) and then separate G(s) into numerator and denominator. N(s)/(D(s) + K*N(s)). Now if K is 0 then the transfer function is N(s)/D(s) which is G(s), so the roots start at the poles of the original transfer function. When K is increased the denominator D(s) + K*N(s) starts to behave more and more like just K*N(s) which are the zeros of the original transfer function. Does that help?

    • @serialglobetrotter
      @serialglobetrotter 9 років тому

      Brian Douglas sir , i have few problems , 1st ) there was a question where i was asked to plot the damping ratio line with just OS% given as 15% how do i do that? how to plot damping ratio line ? 2nd) how to calculate natural frequency & damping ratio in case of a 3rd order transfer function ? kindly please refer back...thank you!!

    • @ph7ryan
      @ph7ryan 9 років тому +2

      ID Jeet 1) There is an equation that relates %OS directly to zeta, %OS = exp[(-z*pi)/sqrt(1-z^2)]*100, where z is zeta (the damping ratio). There's a few ballpark, pre-calculated OS's that are good to remember, 5%, z=.7, 15%, z=.5, 35%, z=.3. So you would plot the z of .5 when given a OS of 15%.
      2) 3rd order+ functions can always be broken into 1st and second order systems. You would simply factor out a first order to create a first order and a second order, and your natural frequency would be the frequency of the second order response.

    • @serialglobetrotter
      @serialglobetrotter 9 років тому

      ph7ryan thank you very much... that was helpful ..

  • @MrDoz01
    @MrDoz01 11 років тому

    the amount of planning that must go into this ...so good ...thank you so much

  • @BrianBDouglas
    @BrianBDouglas  12 років тому

    Well put Trunks. If I don't have specific phase and gain margins I like root locus (especially to move poles around to meet requirements). For me it tends to make more sense. However, if I'm designing a filter for a sensor (lead, lag, band pass), I like the Bode plot. If all you want is for your system to be stable and you don't care whether it oscillates or has a certain damping ratio then all you need is for all poles to be in the left half plane. And that's easy to see with root locus.

  • @deanw8206
    @deanw8206 4 роки тому +1

    You need to grow your channel and cover more topics. You just explained the 2.5 hours of confusing controls lectures I sat through in under 15 minutes.

  • @StevenMcconnon
    @StevenMcconnon 12 років тому

    Thank you. I'm an engineering student who is trying to teach himself control systems and this helps a lot.

  • @santiagoricoy1313
    @santiagoricoy1313 7 місяців тому +1

    I met an old coworker of yours! She heard I was doing controls and immediately recommended your videos; I smiled and said, yes, I've watched every single one.
    If I taught the class, the lectures would just be practice problems, and the homework would be to watch your lectures. 😂
    Also, at about 7:29, I thought the imaginary portion was the damped frequency, not the natural; I thought the requirement forms a circle. Anyone able to help me understand?

  • @condedennisful
    @condedennisful 9 років тому

    excellent explanation. i like how you explain very quickly and don't waste time like other videos.

  • @nickvonklemperer4807
    @nickvonklemperer4807 11 років тому

    The night before an exam, this has got to be the best channel I've discovered on youtube. Our lecturer for the 3rd year control course has made an art form out of being vague. This has clarified so much. Is it possible to get a PDF of the video, like a combination of all the notes you've written during the video just on one long PDF.

  • @サメ頭のくま
    @サメ頭のくま 6 років тому

    This is a REALLY good explanation of this. I came for later R.Locus stuff but I decided to watch this intro video (so I understood 99% of it prior to watching). Your explanations are very thorough but concise. I have a friend taking Control Systems next term and I'm going to recommend your videos!

  • @akankshapassi8962
    @akankshapassi8962 8 років тому +1

    +brian douglas you are love. Your videos are gonna save my exam tomorrow. Thanks.

  • @q1q1q1q1q1q1q1q11
    @q1q1q1q1q1q1q1q11 2 роки тому

    Thanks for your clear teaching style, it is much appreciated.

  • @余坤奇
    @余坤奇 7 років тому

    we dind`t learn any thing about the loucs root method but our teacher ask us to do a course work with this. thank for u help , your video helped me a lot !

  • @jacquesnicolay9221
    @jacquesnicolay9221 7 років тому +1

    Thanks for making UA-cam useful. Thank you sir.

  • @mohamededbey
    @mohamededbey 3 роки тому +1

    Great content as usual
    Control engineers are very proud to have you

  • @xxanimangaloverxx
    @xxanimangaloverxx 9 років тому

    I wish I could print out what write out in your videos. Best notes ever.

  • @guruprasad_1984
    @guruprasad_1984 Рік тому

    Super Brian...you have covered beautifully the significance and notion of root locus in a 13 minute video....

  • @jorgerive7335
    @jorgerive7335 5 років тому

    Your are a talented instructor!! Excellent job on these tutorials --they move quickly, they're thorough, and your explanations are clear and presented in a very easy-to-understand fashion. Kudos and thank you.

  • @abdohajar908
    @abdohajar908 7 років тому

    Sir, you don't know how helpful these videos are!!!
    Thank you :)

  • @Berilium2
    @Berilium2 9 років тому +1

    Good man Brian! You're saving my degree one video at a time!

  • @dr.ganeshbhokare6547
    @dr.ganeshbhokare6547 2 роки тому

    Very simple and conceptual explaination of root locus...really very impressive due to to simplicity of explaination

  • @jaimemartinezdiaz1004
    @jaimemartinezdiaz1004 4 роки тому

    These videos tie all my lectures together. Amazing

  • @johnhan75
    @johnhan75 9 років тому

    oh my god.. Your video is so much helpful, I can't belive it,,, I am an university engineer student, and I actually think you teach way better than our proffessor, eventhough school I am attending is quite a good school.. thank you so much for lecture, have a good day!

  • @MrAskOnce
    @MrAskOnce 11 років тому

    Very well put together... I'm about to have to develop the root locus for a project I have in my controls class and this is so much better of an explanation in ~13 minutes than my professor has given in 3 lectures.
    Woo.
    Will continue watching the others -- thank you for posting this. xD

  • @elmerosorto1680
    @elmerosorto1680 2 роки тому

    Amazing explanation, i am reviewing all the content i've learn in these university years, because this is my last semester, thanks for the good work.

  • @elzarqua
    @elzarqua 7 років тому +1

    wow, learnt more in this tutorial than i have all semester! love how you link everything together! cheers!

  • @idrissalim8348
    @idrissalim8348 5 років тому

    this could replace almost any control theory course in engineering schools!! Great work

  • @re.liable
    @re.liable 3 роки тому

    I hope you won't ever take down these videos. It's still a little bit over my head but I expect to be coming back to these over and over again lol
    EDIT: I just noticed that I'm already subscribed. I must've seen another video series from you before. You're the best, thank you very much

  • @sizmostudent
    @sizmostudent 6 років тому

    Finally, I understand it, I have been trying to understand it for 2 months, thanks a lot for this amazing video!

  • @seang5476
    @seang5476 Рік тому

    Thank you sir! Helping students 10 years later

  • @debasismt
    @debasismt 4 роки тому

    In my college time I thought I will never be able to understand this. Now its crystal clear.

  • @shengzhu9716
    @shengzhu9716 9 років тому +1

    Great teaching. You really help me understand control much better!

  • @EdgarPoe_Raven
    @EdgarPoe_Raven 7 років тому

    4 minutes to get to know what I NEEDED. Dude,you have no idea how grateful I am. Perfectly explained. I should donate you to your Patreon or PayPal or whatever, for the coffee at least, you fucking deserve it.

  • @ECOMMUSK
    @ECOMMUSK 7 років тому

    these are amazing examples. I did not know to think of it like that. It makes more sense when you say the marketing department says a system with a mass of 1 will sell the best, and the spring department wants to use a constant of 1 etc... thanks!

  • @hebazo3ar
    @hebazo3ar 5 років тому

    You are an engel , I am crying of happiness.

  • @BrianBDouglas
    @BrianBDouglas  12 років тому

    Hi Echo, is your question why I didn't set b such that no oscillations occur at all (poles only on the real axis)? You could set b to be anything along that blue line that I drew. The reason I didn't choose a larger value is because when you're buying an actuator (like a damper) typically the larger the value (or larger damping) the more expensive the unit, the larger the unit, and the heavier the unit. Normally I try to select the cheapest smallest part I can that still meets requirements.

  • @nkk918
    @nkk918 11 років тому

    YOU SHOULD HAVE DONE THIS AGES AGO! I absolutely love the videos. To the point, interesting, amazing! Simply amazing! Thank you so much :) I have an exam I'm sure I'll pass thanks to you :) I'll even take up contlrol as an elective now coz you've made me understand and fall in love with it. THANK YOU!

  • @BrianBDouglas
    @BrianBDouglas  11 років тому

    Hi there, yes you are correct, the natural frequency should have been a circle. I thought I added an annotation explaining my error. I'll go check now and if I don't I'll add one. Thanks for reminding me.

  • @pridez6132
    @pridez6132 4 роки тому

    Brian, your 13 mins lecture is more clear than my lecturer who used 3 hours to explain this one.

  • @SolidSnakePlissken108
    @SolidSnakePlissken108 8 років тому

    i am racing against time to study for an exam which is about 8 hours away (it is my last ever exam at uni i might add), and 3 hours ago i was in utter panic that i will fail at the Root Locus problems that await me. i cant happily say: not anymore. why? because of your Root Locus lectures. Thank you.

  • @zahidfaheem3233
    @zahidfaheem3233 5 років тому +1

    love it when you find a video that gives more than you expected! thanks a lot bro and hope the book becomes a bestseller :D

  • @jaydesai7386
    @jaydesai7386 4 роки тому

    very well and logical video . Understanding level is very high . Well done.

  • @ryanvickramasinghe1971
    @ryanvickramasinghe1971 5 років тому +1

    give this guy tenure already.

  • @pelonags
    @pelonags 2 роки тому

    You're a student's dream, Brian! Thanks so much!

  • @MANGOBAPRODUCTIONS
    @MANGOBAPRODUCTIONS 7 років тому

    Thanks for your passion of sharing knowledge to the world, keep the good work. You saved my control course and made me enjoy it.

  • @protiiooi
    @protiiooi 9 років тому

    This is awesome! I finally understand what my teacher has been trying to teach for the past few weeks

  • @Postermaestro
    @Postermaestro 8 років тому +2

    Love the "side notes" in your videos. It seems to me like these are things that have confused you in the past, and most likely confuse students (like myself) taking these courses.

  • @drsandeepvm5622
    @drsandeepvm5622 3 роки тому

    Been teaching control engineering since many years, but understood today 😇. Thank you Sir 😊

  • @codesrhodes3757
    @codesrhodes3757 3 роки тому

    Just amazing sir. Don't have the words to describe how awesome you teach It is fabulous.

  • @gabrieljalil1562
    @gabrieljalil1562 9 років тому

    Great tutorial! Not that many tutorials of this quality discussing engineering subjects. Keep up the good work!

  • @condedennisful
    @condedennisful 9 років тому

    GADDAMMIT!!!! thats the best explanation i've ever seen on youtube and I use to study from youtube.

  • @shrikantmahapatra5135
    @shrikantmahapatra5135 8 років тому

    Your explanation of concepts is awesome!!