How velocities of center of mass is calculated? Exercise 3.1

Course Support Robot Dynamics and Control
1

Hi! What is the intuition behind link center velocities formulas?
vxc2 = vx2 - w2*(yc2-y2)
vyc2 = vy2 - w2*(xc2-x2)
vxc3 = vx3 - w3*(yc3-y3)
vyc3 = vy3 - w3*(xc3-x3)

2

Hello @ermolenko_nikita ,

That equations are wrong. The correct ones are:

vxc2 = vx2 + w2*(0.5*math.cos(th2))
vyc2 = vy2 - w2*(0.5*math.sin(th2))
vxc3 = vx3 + w3*(0.5*math.cos(th3))
vyc3 = vy3 - w3*(0.5*math.sin(th3))

I’ve updated the equations in the notebooks as well, though it might take some time to show up in Production.

Best,