Hi Stéphane,


On Thu, 08 Mar 2012 11:28:55 +0100,
Stéphane Magnenat <stephane.magnenat@mavt.ethz.ch> wrote:

> Dear community,
> 
> At some point, I would like to integrate planner9 [1,2], my HTN
> planner, into ROS.

That looks pretty interesting, looking forward to having this in ROS!

> At that occasion, it would be nice if planner9's
> node could conform to a standard HTN-planner interface. I have been
> looking for one but did not found any. Currently planner9 can
> distribute search on multiple nodes using avahi and be called using
> D-Bus. The interface to D-Bus could be a source of inspiration (at
> least it works for me), here is a rosmsged version:
> 
> * HTN/Atom.msg:
> String relation
> uint32[] params
> String value
> 
> * HTN/State.msg:
> Atom[] atoms
> 
> * HTN/Task.msg:
> String head
> uint32[] params
> 
> * HTN/Plan.msg:
> Task[] actions
> 
> * HTN/StartPlanning.msg:
> String[] constants # for debug output
> State initial_state
> Task task # task to do
> 
> * HTN/PlanningSucceeded:
> Plan plan
> uint32 total_iteration_count
> 
> * HTN/PlanningFailed:
> uint32 total_iteration_count
> 
> These messages assume:
> * constants are represented by integers
> * relations are represented by strings
> * values are represented by strings
> * the goal is specified as a task
> * the planner node has a description of the planning domain, and only 
> problems are specified dynamically.
> 
> 
> What do you think? Are there people interested in such interface?
> Should we make a REP?

I would be interested in such an interface, but I'm not sure if enough
other people are to justify a REP (comments, anyone?). Maybe you just go
on and define these messages in a separate message package (what about
the name htn_msgs or htn_planning_msgs?), and others can adapt it.

We've written a tiny ROS wrapper for JSHOP2 (not yet public), and it
would be easy to adapt it to your format.

One comment on your messages: StartPlanning, PlanningSucceeded and
PlanningFailed look like they should best be combined into an actionlib
action definition. Other than that, the messages look fine to me.

Cheers,
Martin

-- 
Dipl.-Inf. Martin Günther
Universität Osnabrück
Institut für Informatik
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