Derivation of Transfer function from a Bode Plot

This video clearly explains how to derive a transfer function if a bode plot is given. If you want to find out the bode plot of a given transfer function, follow this link : • Bode Plot of a Transfe...

[@philippebarbie3829]

Never seen it better explained. Thank you!

[@ChinmayaASV]

Thank you. Glad it was helpful. All the best !

[@mihaifrunza2482]

Helpful Tutorial ! Thank You ! Just one question: What if we don't have a slope of 20 db/dec ? what if we have a slope for example 16dB/dec ? How does it influences our subsystem order ? (T1, T2, T3 ..and so on)

[@matthewjames5619]

Great explanation, many thanks!

[@elianerachkidy5137]

the video is quite helpful but what if there was a complex pair of poles how would we be able to deduce that from a given Bode plot

[@ant8427]

Great explanation, this helped a ton!

[@ChinmayaASV]

Glad it was helpful! All the best :)

[@LennyDeee]

Great video, many thanks mate

[@ChinmayaASV]

I am glad it was helpful :)

[@ilisandhya4646]

It was really helpful, simple and amazing explanation.

[@ChinmayaASV]

Sandhya I thank you. All the best :)

[@zprogress4004]

VERY NICE, clear explanation/walkthrough

[@ChinmayaASV]

Glad it was helpful!

[@fatmakhalil1909]

Thank you, it really helped me !

[@ChinmayaASV]

I am glad it was helpful.. Thank you :)

[@jorll7916]

It helped. So thank you!

[@plidjeezy2542]

You just saved my ass! Thanks bro!

[@shiprakhatri2847]

Great video! Thank you.

[@ChinmayaASV]

Thanks ! Hope it was helpful :)

[@nayanadasari803]

Thanks a ton. It really helped......

[@ChinmayaASV]

Glad it helped

[@tanhuynh2176]

Hello, how do I calculate the constant K when the bode plot doesn't start with a constant line, but with a slope?

[@hajerjm]

I think if the plot starts with a slope then that means there’s a pole/or zero at the origin. Let’s assume the slope is decreasing so that’s a pole at the origin. First take K=1, then normally the pole’s line would start at 20dB and decrease to cross the frequency axis at w=1 (Im assuming u label ur semilog paper starting at 0.1) (the line has a slope of -20dB/dec so at 0.1rad/sec, GdB = 20 , and at w=1rad/sec, GdB=0) (slope = -20dB/dec : check). Now if K was some other number, just take the difference of the point 20dB and the point where the slope line starts off and say that 20logK = that difference. I hope i am correct though nothing is certain

[@akashshrivastav2619]

Really helpful sir

[@uttam4948]

Sir, in case of bode plot to transfer function, in all questions, wc1 value should be given or not?
Please reply me sir

[@gnquince]

if there is 12db/oct change in first slope decrease and last slope increased by 6db/oct how i do

[@tumul1474]

thanks a bunch...gr88 explaination

[@ChinmayaASV]

Tumul Sharma You are welcome :) Hope it was helpful.

[@mohammedayaz9397]

what about constant term? it its given in TF

[@opioasde]

what if there is a non touching loop with the forward path? how is ∆k written then? This is reference to your next video of SFG

[@nhaminh88]

Hi, Could you let me know how to drive transfer function if the slope is not 20db? For instance, 30db or 40db?

[@ChinmayaASV]

There will be 40 db. Then add a square to ur term. Like (s+2) ^2. They never ask for 30 db.

[@anindita4thoctsaha]

Thank you so much :)
Please please please upload a video explaining how to draw nyquist plot...
I am having my control systems exam tomorrow...
please...
thank you once again :)

[@ChinmayaASV]

Since ur exam is close, better refer to Nagoor Kani one for Nyquist plot.... All the best again :)

[@adizeus7192]

how is T3 going from - 20 db to 0 it remains constant right .. please help!!!

[@shwetarai4521]

Sir plzz give some more video to calculate Transfer fxn from bode plot

[@HackingDutchman]

This video is only valid for critically damped systems(damping constant = 1). Because you show no way to calculate the damping factor if a Bode diagram has a ''hill'' in it, a resonance frequency.
To include that:
Take the distance in dB from the gain to the top of the ''hill'', if your gain is 40dB and the top of the ''hill'' is with 54dB, than your answer is 54-40=40dB. Lets call this distance X for now.
X [dB] = 10^(X/20) = answer.
1 / 2Y = answer, and then your Y in this case is your damping constant, a lot of times named zeta. You can fill this zeta in in the standard second order transfer function.
Also, to verify if you have the correct corner frequencies be sure to check the phase diagram of the bode plot, it is clearer to see the corner frequencies from the phase plot.
That out of the way, this method works fine, thanks!

[@kuljitray2803]

Sir, if I upload a picture and request you to derive the corresponding transfer function from a certain Bode Plot sketch then will you please solve it??

[@ChinmayaASV]

mail it. I cud giv it a try

[@nnaveen646]

+Chinmaya A.S.V i too have a doubt sir. can you please share your mail id so that i can mail you the question...

[@dineshreddy7773]

plz give me an other example which consists of 'k' value for better understanding....plzzzzzzzzzzzzzz

[@NMJC1]

If the constant plot (line) on the bode plot is say 20dB then 20log K = 20dB, this becomes log K = 20dB/20 =>>> K = 10^(20dB/20) = 10. So K equals 10.

[@zyber8525]

you've only chosen the most simple bode plot to use.....

[@Shuey272]

... seriously you didn't fix the video's audio....

[@manyakaushik6768]

That is such a terribly mixed accent

[@pnachtwey]

So where does the Bode plot come from? This is a waste of time. It is teachers teaching what they have been taught and think is important. What is important is to record the control signal and response as a function of time and use that data to find the coefficients of a differential equation. This is called system identification. Now you have the transfer function. Doing what is shown in the video is backwards.