Robotics - Inverse Kinematics - Example

Connor with UConn HKN explains how to analyze a 3-link robotic manipulator using inverse kinematics.

[Ben-zsqo]

dude looks like he hasn't slept in 14 weeks

[seasnek]

The DH convention for prismatic joint 2 should have Z2 pointing along the direction of the manipulator (as shown), however X2 and Y2 should've been swapped. Do the right-hand rule and with DH convention and you'll see this.

[hernandobolanos]

Your explanation is the best one I have found. Very clear I suscribed and look what are you sharing about robot's Arm. I am sure there are a thousand of way to perfomr more complex situations, but the concepts explained and technic is excelent. Please include in comments of this video or as answer the list of videos associated to this topic.

[stefankeilich]

when a vector or axis is pointing into or out of the boards plane please use the convention of an X if into and a dot inside a circle if out. Think of it like an arrow entering into or exiting the plane. this helps more then drawing improper arrows like in your side and top view eyes. Thank you for posting this.

[agustinsantanaromero]

Thanks for sharing this example! Is there any other example considering 3 revolute joints? I´m having trouble with de "wrist" joint...

[Ferberius]

Inverse kinematics and inverse writing XD

[TheStuwy]

I dont see how d2 affects z3, isnt its supposed to be d3=Z30-1? Because youve flipped the axes?

[prathameshmore]

You are good....I appreciate you are writing from left hand just cz we can understand it.

[jvenmusic]

Let's say there was a fourth prismatic joint connected to the 3rd joint, and this joint was oriented such that its z is the same as x_2, i, .e., the axis of rotation is different then the other joints. Would this require a third view to do thei nverse kinematics?

[MichaelBrowne_esq]

@2:40 Why abandon DH parameters on the last joint? Shouldn't X2 and Y2 be swapped?

[kishorebellada]

in top view why you did'n use the last interceptor?

[yaredabraha]

@UConn HKN, please explain how X3 is perpendicular(adjacent), it seems wrong for beginners like us. so we are missing something there.

[bryannaing]

I have no idea how any of this works nor do I know how I ended up here, so feel free to point out my idiocy at this question, but how are x3 and y3 perpendicular in the top view? I would assume for that to happen, theta can only be one specific angle, and rotating it in any amount other than that would ruin the right angle triangle it forms.

[campbellmorrison]

But on your top view 1 + d3 are not in a straight line are they? if they are no then Pythagoras doesnt apply?

[moosa]

x3 and y3 came by drawing vertical line from end effector position n using pythogarous therom..

base square+opp side square= hyp square

[juancamilomogollon]

prodian colocar mas videos de cinematica inversa y sobre robotica en general es de gran ayuda para personas auto didactas gracias

[brickbybrickdesignstudio]

for a 3D animator it's a little confusing to keep seeing actual Y as Z and Z as Y since you explained them inverted for me. :)) thank you thou great video to understand basics much appreciated!

[lukedowneslukedownes]

I’m confused on where you put your points? Is it centered? Or on a edge?

[mojoomla]

How is this video produced ? Is he writing from the otherside on a transparent glass board ? How can he write in reverse ? Somebody please clarify. thanks

[raghavnandwani]

At 10:39 the direction of y should be opposite ?? As from the earlier figure y never changed its direction as he said on 2:26 !!