Modern Robotics, Chapter 3.3.2: Twists (Part 1 of 2)
This is a video supplement to the book "Modern Robotics: Mechanics, Planning, and Control," by Kevin Lynch and Frank Park, Cambridge University Press 2017. See modernrobotics.org for information on the book, free software, and other materials.
This video introduces the 6-vector twist, a representation of the linear and angular velocity of a rigid body. A twist can be represented as a normalized screw axis, a representation of the direction of the motion, multiplied by a scalar speed along the screw axis. A screw axis or twist can be represented in any frame, such as the body frame or the space frame.
This video is a brief summary of material from the book, and it is not meant to stand alone. For more details, such as an explanation of the notation, please consult the book and the other videos.
Playlist for Chapter 3: • Modern Robotics, Chapt...
Playlist for all book videos: • Modern Robotics, All V...
KZread channel with all playlists: / kevinl2145
Wiki for the book, including software and other supplements: modernrobotics.org
Modern Robotics is now a series of online courses on Coursera! www.coursera.org/specializati...
Пікірлер: 11
I don't understand why this series does not come up so easily in the searches. These are really good and such a useful service to robotics students! And thanks especially for making the book available.
Sir can you give example of Vb?
How/what do I learn about the math before I go into this course?
Lie group and algebra are so difficult!
3:50 - h is finite then theta_dot defines not only rotational speed, but also linear speed, isn't it?
@zevminsky-primus7434
3 жыл бұрын
Well he's normalizing angular speed to have a magnitude of 1 in the S vector, so it only defines angular speed. If theta_dot denoted both, then ||S_v||/||S_w|| would always have to be the same.
@MrSerozka
3 жыл бұрын
@@zevminsky-primus7434 Am I understand right that skrew can represent either linear or rotational speed and not both at the same time as it would make ||S|| > 1?
@zevminsky-primus7434
3 жыл бұрын
@@MrSerozka Well it can't represent the magnitude of both at the same time because there are two independent magnitudes, and just one theta_dot variable.
Why is the angular velocity negative 1 in the y hat direction and not postive
@alpharomeo1521
Жыл бұрын
I think its because the rotation is happening in the counter clockwise direction (against the Y-axis)? Although I could be totally wrong
Probably the least clear video in this playlist