Modern Robotics, Chapter 2.1: Degrees of Freedom of a Rigid Body

[@СаулеИбраимова-з9к]

this is some hardest way to explane DoF

[@parameciumcheese]

Thank you all for these videos! I'm so excited that you all have put so much effort into making this information available with the book and such. Thanks.

[@sachinfulsunge9977]

Thought this was going to be beginner friendly

[@RohanKumar-oz8tc]

Thanks for the video. I didn't understand how when specifying C, we have moved B away from the circumference of the point A. Isn't B supposed to be at the circumference of A?

[@logicraju]

Can't understand 1:46. The CSpace should be a disk, right? How come it became a torus?

[@physicsmadness]

u r right....i guess the first joint is orthogonal to the second...he has mistaken it...it should actually be an annular disc...

[@mccunnj]

It is the result of S1xS1. 1 Joint rotation is the angle on the torus from above, and the second is the angle within the torus itself.

[@paramitapal392]

Consider a joint between two rigid bodies. Each rigid body has mm degrees of freedom (m=3m=3 for a planar rigid body and m=6m=6 for a spatial rigid body) in the absence of any constraints. The joint has ff degrees of freedom (e.g., f=1f=1 for a revolute joint or f=3f=3 for a spherical joint). How many constraints does the joint place on the motion of one rigid body relative to the other? Write your answer as a mathematical expression in terms of m and f. ans?

[@thakervedant3170]

here the Answer is m-f. as per the equation given over here, f+c=m . and we want the value of c in terms of m and f.

[@الاستاذتزروتي]

thank you mister . its helpful

[@goktugguvercin8069]

In the video, it is said that there is only one number needed to specify location of point C. I could not understand it. How can we specify location of point C with one value ?

[@sparshmecwan2962]

See the location of point C is represented by 3 numbers but it's position has to be in the circle that A and B formed which means it has to be at a particular distance from A and B ,and whatever the position might be in that circle, it IS going to be represented by 3 coordinates. It's not the coordinates of point C that is decreasing, its the degrees freedom of it's location. Edit: I'm replying 7 months later, you probably would have mastered robotics until now. xD

[@physicsmadness]

a circle is parametrically represented with just theta...any curve is intrinsically one dimensional..

[@sidharthsaratrajbatchu6593]

​@@sparshmecwan2962 but still your answer is helping me with same question But professor mentions point c wrt a as an outer parameter of the B sphere

[@charismaticaazim]

Simply take any object (e.g. pen, shoe) & fix its x & y co-ordinates (i.e. keep it constant), then you'll observe that you only need one more number to specify the location of the object.

[@hichemsetif1741]

hey nice video ,can you do a video for 5 DOF bipedal robot .thanks if have one send me the link.

[@Luhpu]

شرح صعب جدا وغيرمفهوم