Understanding the Rotation Matrix

[@suddhasattasaha4793]

Please continue this series, extremely helpful to understand such complex topics. Excellent demonstrations! Please upload more videos on this topic

[@hiankun]

The introduction of extrinsic and intrinsic rotations was really helpful. Thanks.

[@Kejtoo]

I remember struggling at University for hours to understand this topic, but with this clear explenation and memorising tips life could have been much easier!

[@JUNGELMAN2012]

Brilliant animations!

[@nicodell6192]

I liked your explanation of 3d rotations, and regarding 2d, I thought SO2.

[@ArticulatedRobotics]

Oh man, that is too good haha

[@ayyasif]

thank you so much

[@aloksahu1783]

Please upload more videos on the topic of rotation

[@paulramasco6769]

I finished my degree that had a focus on robotics in november so this is an awesome refresher. However, the right hand rules you shown jacked my head up, probably because I'm used to the general electronics rules (right hand and left hand) are thumb up and middle finger pointing out, so right hand rule here is exactly the same as left hand rule. I'll have to review my books if they explained it the way you did. They probably did, I just don't remember.

[@ArticulatedRobotics]

THanks!

[@florist_notes]

Thank Youuu :D

[@Abdellahhassaine-of6dx]

Thank you very much for this video, I just can't figure out why the sin terms in 1:40 have signs like that, shouldn't it be the inverse? (I think that in counter-clockwise rotation the upper sin is positive and the lower sin is negative). You can check this wiki page to see: en.wikipedia.org/wiki/Transformation_matrix#Examples_in_2_dimensions

[@joshnewans2196]

Hmm, I think the Wikipedia article might be wrong, unless it is just trying to tell us something else (like rotation of coordinate systems). The frame you've noted (1:40) shows the full derivation! Check out the Wikipedia article on the rotation matrix en.wikipedia.org/wiki/Rotation_matrix which has the correct matrix in the opening paragraph and if you're still not sure, try some examples. A 45deg CCW rotation should be [0.7, -0.7;0.7, 0.7]. If we multiply that by [1;0] (X unit vector) we get [0.7;0.7] and if we multiply by [0;1] we get [-0.7;0.7] which are correct. If it was the other way it would be backwards.

[@Abdellahhassaine-of6dx]

​@@joshnewans2196 Yes I understand now, the Wikipedia article I mentioned deals with something different (even though very close). It talks about the rotation of the coordinate system for fixed vectors. While in this video the vector is being rotated in a fixed frame of reference. Interestingly, however, the CCW-rotation matrix of a vector is the same as the CW-rotation matrix of the reference frame, which is because the rotation of a vector by theta in one direction equals mathematically the rotation of the entire reference frame in the opposite direction by the same angle.

[@malindailankoon]

Im following your tutorial on how to setup ros on computer and raspberry pi, the network setup video is a bit unclear, do i have so give static ip addresses to both the pi and the computer?

[@sikirusalau9460]

Amazing video. What tool was used to make the animation of the angles?

[@unaigranados4088]

I want to get that GUI also

[@ArticulatedRobotics]

I use the Manim software, originally written by Grant of 3Blue1Brown (amazing channel)

[@unaigranados4088]

@@ArticulatedRobotics Can you share code?

[@alexbayarsaikhan]

Thank you for your videos. I really like your mobile robotic series. I'm new to robotics and have a question. What books do you recommend for beginners who want to learn more about ROS 2 with Python?

[@THEDOOMSLAYER999]

Hello, thanks for the video, would you like to make a tutorial, like you used to make about ros robot , but with robot dog?

[@0jeetparmar0]

hey josh ,can you please make a ackerman car tutorial just like last project , thanks

[@bhollywood01]

once again another dude on youtube that thinks everyone coming on here for help are looking for a guy talking learning the theory and the history of robotics, people wanna see how to put shit together, wiring, what kind of controllers to use and watch them build it. they don’t want to go to school on youtube.

[@ArticulatedRobotics]

Yeah I mean each to their own. Many people do want to go to school on KZbin! Or need additional resources to help them understand what they're learning. As much as some people want to see things get wired up, others need to know how to code transformations. The sort of knowledge I'm sharing here is used every day in industry! (Source: my day job)

[@mrechbreger]

@@ArticulatedRobotics if you extend it a little bit you also get scaling :-) I also use this at work the beauty is how simple yet effective all that is.