[ODE] Fwd: Ball and Socket or (Universal +Hinge)

[Jaap Stolk]

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---------- Forwarded message ----------
From: Jaap Stolk <jwstolk at gmail.com>
Date: Apr 11, 2006 7:08 AM
Subject: Re: [ODE] Ball and Socket or (Universal +Hinge)
To: vector at acm.org


On 4/11/06, Brian Dexter Allen <chokma at gmail.com> wrote:
> Right, I don't believe the Angular Velocity info is (easily) available
> from the API.  For my AMotors (I'm also doing controlled humanoids) I
> just settle for comparing the current angle to the previous, which
> works fine for small time-steps and smooth motion.  That said,
> retrieving the current angle works fine for Euler-mode AMotors.  FWIW,
> I'd be happy to send you my setup for ball-and-socket joints with
> Euler AMotor drivers if you might find it useful.

yes that would help me a lot.

> So, how are you
> planning to do the motor control?

in short, i simulate (torsional) springs, and set the position and
stiffness before each simulation step. like on the bottom of this
page:
http://www.ai.mit.edu/projects/humanoid-robotics-group/cog/hardware.html

the code is on the bottom of this page:
http://jwstolk.xs4all.nl/wisse/?M=A
(this was still without the amotors)

jaap.