Use Mk,gk instead of Yk,zk

[moorepants]

I use $Y_k\dot{\bar{q}} + z_k - \bar{u}=0$ when introducing kinematic differential equations but then use the notation $\mathbf{M}_k \dot{\bar{q}} + \bar{g}_k = 0$ later. M_k is Y_k and g_k is zk-u, so I should just use one of these notations. I could change to only using the Mk,gk form.

[Peter230655]

I assume, you compare eq (110) to eq (201) in your script (?)

1. In eq (110) in your lecture, the dot seems to be 'inside' of the q, rather than on top of it, at least so it looks on my screen.
2. IF I am looking at the equations you mean, does eq (201) not assume that $\bar u = I \dot{\bar q}$ ?

[moorepants]

When viewing with Firefox on my computer this is what I see for Eq 110:

[moorepants]

Eq 201 is this for me:

First equation on https://moorepants.github.io/learn-multibody-dynamics/nonholonomic-eom.html

So I'm not sure if that is the equation you meant to refer to.

[Peter230655]

Eq (110): I opened your lecture from GitHub. Your display looks right, must be an issue with mine.

Eq (201): Yes, this is the one I meant in my reply. Which equation did you refer to originally?

[moorepants]

I was referring to 191.

Regardless, 201 does not assume u = q'.

[Peter230655]

I think, maybe $M_k$ is better as it 'indicates' the 'mass matrix of the kinematic DEs.'
NB: Now my equation (110) is displayed well. Must have been an internet problem this morning.