RE: Open source robot controllers

On Mon, 24 Sep 2001, Tiller, Michael (M.M.) wrote:

[...]
> >
> > It could be interesting for you to take a look at modelica.org, for
> > the modelling language. I do have some objections against the precise
> > way they are doing things, but it's by far the most advanced thing at
> > this instant.
> >
> A minor clarification.  Modelica covers the kinds of requirements
> you describe for connectors.  In addition, there are a (currently
> informal, I think) set of annotations that allow Modelica models and
> hierarchies to be represented and connected graphically.  These are
> implemented by Dymola (http://www.dynasim.se) and MathModelica
> (http://www.mathcore.com).

Thanks for the clarification. But they don't have any open source
implementation available, as far as I know?

> Finally, Modelica goes beyond just requiring pairs of effort and
> flow variables.  For example, in multi-body systems it is often
> necessary to express these quantities as vectors.

This is of course a necessity for robotics.

> Furthermore, in
> thermodynamic system (my area) we often have far more complex
> connectors where the flow and non-flow variables are not balanced.

What do you mean with `not balanced'?

[...}
> My caution to anybody developing a control system tool is to not
> forget about the plant. :-)

Indeed! And this becomes more and more important as we are going
towards _interaction_ between machines and humans...

Herman