@@speedracer1702 Been more than 2 years, but here goes ahah. I am in a robotics undergrad class and we are mainly dealing with PID. Anything cool you can share about LQR control for your robot? What did it do and why did you go with the LQR method? Anything really. Very curious to learn more thanks!
Hey Brian, what an absolutely mind boggling video. I can now literally explain my Professor what LQR control is all about, thanks to you. Just brilliant! Who says only actors can be superstars? You are one. Thanks a lot.
These kind of videos can have the universities close their doors, and be left with certification only or distant learning. I mean who needs professors' lectures after this, really. :) I have been familiar with pole placement and LQR for years, but really wanted to find the video explaining it in simple words for my own sake. The whole series is brilliant, I am leaving comment of gratefulness to this one in particular, for the reason I stumbled on it firstly. Great job is a diminutive here.
I'm studying Control and we have a space-state module which at first it was easy, but gradually getting harder to understand. However, after your videos it really help me a lot since you made it really simple to understand and even gave different methods, but what help me the must its showing how they can be apply to different systems. Now I even think Space-State is actually really cool and would like to learn more about it and even apply it in my personal project and such. Thank you so much.
Hey everyone, thanks for watching this video! If you have any questions or comments that you'd like me to see, please leave them under this comment so that I get notified and can respond. Cheers!
@@ahmadalghooneh2105 I knew someone would ask and I should have been prepared. Yes I can ... but the code was written quickly to get this video out so it is horribly written. I'll get it up on Github shortly and let you know.
Brian Douglas so much thanks brian, no matter the order, I just wanted to know how did you manage to make the plots so cool, A huge fan of yours, Regards
I'd like to thank Brian for that fantastic take on the LQR explanation. I had understood the math behind it but I hadn't get the intuition I should have gotten while developing my LQR model and now I feel really ready to give it a shot.
The issue I come across is choosing "optional' values for Q and R. I prefer pole placement for SISO systems. It is easy to determine the response and effort. I usually want to place the poles on the negative real axis. I can move the poles to the left ( more negative ) until I hit one of two limits. 1 output saturation as mentioned. However, usually the problem is feed back resolution. Placing the closed loop pole on the negative real axis does not guarantee that there will be no over shoot. The closed loop zeros can cause over shoot if the closed loop zeros are closer to the origin than the closed loop polse. Sometimes the closed loop zeros must be placed too. LQR has an advantage for MIMO systems. If the Q matrix is chosen correctly, the closed loop zeros will be close to the close loop poles almost canceling them out and improving performance.
I haven't finished the video yet but I found exactly what I was looking for. Thank you for sharing this in such an intuitive way to understand what I am doing haha. Keep shining :D
Great to hear! I also have a video on the Algebraic Riccati Equation which might help as well: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-ZktL3YjTbB4.htmlsi=MWLW8nn0S9zPjjCG
It was really nice to see your videos, they were quite helpful as refresh and also maybe to understand better what I studied some years ago. Many thanks!
Sir, just now I have watched this video lecture. Thank you for explaining with the simple terms. I have a question. Why the state should be zero for a observer or other design ? Can you please explain me?
If someone is having problems finding the scaling term, try using simulink to see the step response of the system. Matlab and simulink responses are very different. This might be my mistake mishandling matlab, but if anyone is trying to implement this in a real system and nothing works it might be because of this. To give you some context the step response in matlab gave me a scaling term of around 3000 while with simulink I get the gain around 1,6 and with this my system works perfectly.
Excellent video as always but why leave out the part about solving the algebraic reccati equation to find the optimal solution to the cost function, since its just matrix maths and doesn't go into the complex derivations ?
In retrospect that probably would have been better. I didn’t for two reasons though: 1) I usually shoot for 12-15 minute videos and this was getting long and 2) I want to do another video in the future just on this topic. Thanks for the comment.
@@BrianBDouglas oh an I just want to say thank you for your videos both here and on your channel, I'm in my 3rd year on a robotics engineering course and I don't know if I would have made it through my 1st year without your videos.
Hi Brian, thanks for your lecture on LQR. You and Chris have done a great Job on this. Please my question is on the other diagonal that makes my matrix positive definite or semi positive definite in case of R., How can I choose members in case for nxn matrix, for n>=3. its easier for 2x2 to just pick any number and repeat it , just like zero if I am using an identity matrix, but for n>3 is my question. Secondly please can you do a video also for MPC?
Ha! The cow was a bit of video editing trickery so it's not in the code. But the rest of it does exist in the visualization if you check out the code in the description.
@@BrianBDouglas , haha well it was awesome! Little stuff like that makes it way more fun, I was going around showing my colleagues! Your videos are definitely helping me with OJT. Let me know if you're ever interested in visiting NASA AFRC and maybe giving a talk to our new professionals group and I'll try to coordinate something!
Hi, can you explain how the angular acceleration is dependent on the angle by a factor of 0.01? I was thinking dynamics should be like T = I*(angle)'' and no angle terms in it. Thanks for such an amazing video btw
Hey Brian, thanks for another fantastic and very informative video. I am curious would it be possible for you to share the code you used in this video? Thanks for taking the time to create these great videos.
Here's a GitHub where I posted the code for the UFO animation. I'll ask MATLAB to place it in the description so others can get to it too if they want. github.com/aerojunkie/control-tools/blob/master/ufo_rotate.m
