Re: Open source robot controllers

On 24 Sep 2001, Dominic Létourneau wrote:

> I have read the description of the OROCOS project and it seems very
> interesting.

It's still without any code though :-)

> http://freespeech.sourceforge.net/FreeSpeech/html/Overflow/

Thanks! I added the link to the Orocos web page.

I'm looking for such a builder interface: draw a schematic, and you
get a program. But I want to have something better than Simulink, in
the sense that the user can only draw what is physically meaningful.
That is, the `ports' between parts should be compatible, and an
`effort' port should be accompanied by a `flow' port. I guess this is
within the design scope of Overflow?

The physics of robotics (and other areas) is that blocks exchange
energy, as a `dual' pair of `effort' (force, voltage, ...) and `flow'
(velocity, current, ...). I want to impose this constraint when
drawing schemes. And I want to have a coupling with an engine that can
work on the graph structure that one builds, in order to come up with
the best computational scheme. So, I will closely follow what you are
doing :-)

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.

So, I hope we can share some efforts :-)

> http://www.gel.usherb.ca/laborius) to release a project that will be
> called RobotFlow that will include robotic libraries containing blocks
> to build robot controllers from low level actuators / sensors control to
> high level AI controllers (TCA, Subsumption, etc.)

That's very complementary to the Orocos goals :-) ! Great! Orocos
concentrates on the building blocks. We are working on software
framework designs for motion control, task execution, component
commmunication and kinematics.

> I hope this information can be of any help. If you have any questions or
> comments, don't hesitate to contact me.

Just one: don't fall in the trap of Simulink, and make sure that you
impose the constraints that physics imposes. Because I have seen way too
many people make spagetti code with a `tool' à la Simulink :-( Way too
many...

The orocos approach will be a bit different, in that `senior' people
will design frameworks that less-experienced users can fill in; we
won't allow `anything' to be put together :-) Of course, there will be
many frameworks, such that the user is not limited. (But
``guided''...)

Good luck!

Herman Bruyninckx