Standard HW Problem #2: Which is the real open loop transfer function?

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In this video, we’ll go through another standard homework problem so you can see how you can apply many of the things you’re learning into a single problem. The question is, we have two closed loop systems that are equivalent, they have the exact same closed loop transfer function, but they have different open loop transfer functions. So which is the real open loop transfer function for this system? Say, if you wanted to design a control system for it which open loop transfer function do you use?
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[@albertomeneses9160]

When videos from 2017 from Brian beat actual lectures from my professors. LIKE, SHARE AND SUBSCRIBED for this reason!

[@raj-s.]

Glad to see you back Sir

[@MikeDermksian]

Thanks so much for posting this, and I hope I can look forward to more videos like this. I first discovered you while I was taking my classical control systems class in college, and I've since graduated. Day-to-day work doesn't challenge me in the same way school did and I can already feel some of the knowledge slipping away. Videos like this are now one of the few ways I can keep fresh with this stuff! Thanks again and keep up the awesome work

[@xanyula2738]

Say I have a cltf, and I simplified into a single block , with no intention to adjust the gains. now can I simply design a system with that single block transfer function? if yes, will it still have feedback ? Because isn't it exactly the same as the cltf but simplified ? And wouldn't that imply that in theory feedback systems can be designed without an actual feedback path ?

[@erickclare05]

Hello I really liked your videos. I would like to know what software do you use to do the drawing and the video, It looks really handy to teach others. - Regards from Perú, South America =)

[@Counterpoint69]

Excellent! Very clearly presented. Thanks for sharing your knowledge and experience.

[@mnada72]

Please don't stop posting videos with your valuable insights, still there are lots of topics in control not covered. Waiting 🤗

[@AbrarShaikh2741]

Glad to see you back sir. Now go on a non-stop spree of making videos. Your videos not just teach me Control Systems. They inspire me to be a better engineer.

[@ayushkumarsingh616]

This was very helpful. Thanks a lot!

[@mamtakumari-bp3dr]

You cleared my all doubts.. thanks👌

[@emiliotanowe4323]

It's good to see you're back to creating videos, Brian. We know it takes a lot of time to plan and record a new video. One of the reasons why I've decided to enter a master's in systems & control is because of the material you share with us through your channel.

[@alihosseinipour5537]

You're fantastic, Brian!

[@kerimmoral]

Hello Brian, can you do a video on Feedforward control? I would like to listen it from you as well. And thanks for the great videos!

[@hibak8196]

Great video! It was sort of "back to basics" but really eye opening on how all these concepts work together. Thanks a lot for posting and good luck!

[@siebevanoorschot6953]

You're a god amongst men. Thank you.

[@matheussilvaoliveira1555]

Congratulations for your work.

[@johncuellar9349]

Thanks so much for your videos! They've helped expand my understanding so I can design my own stuff. That being said, I'd like a copy of your e-book, please. However, but I'm having trouble contacting you through your channel. Can you please help with that? I didn't see a "send message" tab or button under the "about" section. Thanks!

[@BrianBDouglas]

My email is under business inquiries. But that's OK, I just added my email to the about section paragraph as well so people can find it. You can reach me at [e-mail]. Cheers!

[@youmah25]

welcome back brian we missed you

[@kunalpanchal7751]

In part two of this video, you said if you cut the loop just before the summing point and then measure the gain which will obviously be G(s)H(s) if and only if we take our out point is our breakage point. However our out point is still going to be the take off point pertaining to Y(s)( or simply Y(s)). In that sense the open loop transfer function should stay as G(s). Can you please explain on this.??

[@therohitma]

Kunal Panchal Taking the output Y(s) as the breakaway point when the loop is cut at the summing point would defeat the purpose of having introduced the feedback, right? That would resemble a simple forward path, which you can of course look at as a system with no feedback. But what we're more interested in is in trying to analyse what the feedback signal is going to be like by studying the function that transfers the input to the feedback (which is also called the open loop transfer function of the closed loop system). And through that make some observations about the properties of the system that results when the loop does get closed.

[@kunalpanchal7751]

Alright your statement is quite logical but if you are breaking the path of feedback sensor for sensing, than what is the usefulness of the sensor/feedback path.. Maybe Mr Brian is trying to make this point in above video but still I am unable to pickup.

[@aaaaasssss884]

"It's been a long time, how have you been?" by glados in portal 2 Glad to see you post a new video again By the way, where is portal 3?

[@RicoElectrico]

Exactly, I don't care about HL3, P3 would be the thing ;)

[@FallenWolf-]

You sir are a legend.

[@justinmynest]

Hey, I'm a frequent viewer of your channel and needed to say your intuitions are really good. But in the late videos it seems you are going backwards. In the sense, back to the very basics. I hope in the coming videos we could find some advanced and non linear control systems. Such as pid tuning, non linear system characteristics etc...

[@BrianBDouglas]

You are correct, I am going back a bit. Most of my posts have been on the book I'm writing, which necessarily is starting from the basics. I'm getting back into making videos right now and I thought I'd start with a few questions I received but have neglected over the last year. I'm working on some new stuff ... specifically some discrete control videos. I think I'll cover PID tuning after that. Nonlinear system characteristics will probably be after state space control techniques - and that might be a while since it takes me so long to progress through topics. Thanks for the comment!

[@justinmynest]

Brian Douglas : yeah state space is really a good topic, and I will be eagerly waiting for the controller and observer part. Hope it will not take too long.

[@coaady]

Why is it that the OLTF is G(s)H(s) and not H(s)G(s)? I thought the blocks were supposed to be multiplied against the flow?

[@TheMusterionOfRock]

It's multiplication, it doesn't matter.

[@coaady]

The Musterion Of Rock it would matter in a MIMO system though yes? Or does this only deal with SISO?

[@TheMusterionOfRock]

Cody I don't see how it would matter if you assume the transfer function is something like 1/(s+1) x 1/(s+2) it's gonna be the same even if you multiply the 1st and 2nd or the 2nd and 1st

[@BaselineNL620]

Nice video. are you planning to start making video's again? This would awsome! i am currently trying to get my bachelor degree in electrical engineering and your video's are helping me a lot! keep up the good work!

[@BrianBDouglas]

I will be making videos regularly for the next 6 weeks. Then after that, it's back to my real job and who knows.

[@BaselineNL620]

that sounds awsome. i made a pledge! i can't wait to read the book!

[@BrianBDouglas]

Thanks, I appreciate it!