On Tue, Jan 29, 2013 at 7:17 AM, Adolfo Rodríguez Tsouroukdissian <
adolfo.rodriguez@pal-robotics.com> wrote:

> Firstly I'd like to thank you all for the positive feedback the original
> post received. As next steps, it seems that the Willow Garage / hiDOF
> implementation is a good starting point, as it already allows:
> - Loading controllers as plugins, and serializing their execution in a
> single thread.
> - Creating controllers with arbitrary hardware interfaces.
>
> I'll be giving this a test-drive, with the immediate steps being to:
> - Write an Orocos 2.6 based component that leverages the
> controller_manager library.
> - Trigger each controller with a dedicated, configurable timer event to
> allow each controller to have its own update rate. This timer event should
> be compatible with deployment in hard-realtime and simulated clock contexts.
>

Adolpho,

If you're interested in help with integrating ros_control with orocos, I'd
be happy to contribute, as I was already planning on trying something
similar in a few weeks from now.

With respect to hard realtime (xenomai) and ROS sim time, I wrote a simple
tool as part of my own architecture about a year ago [1]. It's made to just
query the time, but I think something similar could be done to switch
between timers.

[1]
https://github.com/jhu-lcsr/lcsr_ros_orocos_tools/blob/master/rtt_ros_tools/include/rtt_ros_tools/time.h#L36

Also, thanks for starting this conversation!

-jon

ps - I also ported the old PR2 JointSplineTrajectoryController into an
orocos environment last year [2], and it'd be interesting to compare ports!

[2]
https://github.com/jhu-lcsr/controllerman/blob/master/controllerman_controllers/src/trajectory_dispatcher.cpp

-- 
Jonathan Bohren
PhD Student
Dynamical Systems and Control Laboratory
Laboratory for Computational Sensing and Robotics
The Johns Hopkins University

(707) 520-4736
jbo@jhu.edu