MathEngine Arm

[From Bill Powers (991226.0511 MDT)]

I'm been looking over the MathEngine programming, and when you said that
creating a new setup wasn't easy, you were right. There are lots of
unspoken requirements, apparently, so it's not just a matter of setting up
a simulation as in Vensim.

I'm wondering if you would have time to set up a simple arm simulation for
me, with input and output links so I could hook it into my arm program. For
starters, just a 3-df simulation would do: a hinge at the elbow, and a
ball-and-socket at the shoulder. The upper and lower arm segments could be
cylinders or truncated cones, with specifiable dimensions, moments of
inertia about principal axes, and masses. The inputs to the model would be
three torques: two at the shoulder and one at the elbow. The values
returned would be the three angles and angular velocities at the joints. At
the shoulder, the vertical axis (for yaw) would be fixed to the (invisible)
body and the horizontal axis (for elevation) would be fixed to the upper arm.

Since this is basically what you would need for a bug leg anyway, I thought
you might spin off an arm for me, if you were feeling generous. If doing
this isn't compatible with your schedule just say so, but I thought I'd ask.


Bill P.


To: Richard Kennaway;