Hello Gilberto,<br><br>I'll try to explain it better... I need to detect forces for two reasons:<br><br>1 - our robot is an UAV, and as it flies, it will get in touch with objects and environment. On the robot I need to have a few force/torque sensors, that will tell me the force/torque applied in that spot, and then we combine the different values to get a resulting force that will get back to the user using a force-feedback device. <br>
<br>2 - the robot features a grasp/manipulate tool, and I need to read the force applied on it.<br><br>Now, my first idea is this: if I model the sensor as a small pivoting damper, then I could read the position and pose of the damper to calculate force and torque... but this is just a very basic idea, I don't know if it's correct or if there are better ways. (Ideally, this should end up being a MORSE sensor, but that would be a second step, hence why I posted the question here instead on the morse mailing list)<br>
<br>I have also found this on the Bullet forum: <a href="http://www.bulletphysics.org/Bullet/phpBB3/viewtopic.php?p=&f=9&t=3637">http://www.bulletphysics.org/Bullet/phpBB3/viewtopic.php?p=&f=9&t=3637</a>, but I'm not understanding it completely, for instance I do not know what a "proxy" object is and how to set it up. <br>
<br>Hope this is clear enough :-)<br><br>You are saying that the Bullet engine is not extremely precise... can you tell me what are the limitations, or point me to a place where I can get more information?<br><br>Thank you again<br>
<br>Anna Chiara Bellini<br><br><br><div class="gmail_quote">On 6 June 2011 18:09, Gilberto Echeverria <span dir="ltr"><<a href="mailto:gilberto.echeverria@laas.fr">gilberto.echeverria@laas.fr</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
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Hello Anna Chiara,<br>
<br>
For the moment, MORSE does not include this sort of force sensors in
joints. So far, the main developers of MORSE have not approached this
sort of simulation, so it remains an open area for development.
However, maybe other people in the Blender community may have worked on
similar problems.<br>
<br>
It should be possible to measure forces in Blender, but the physics
engine used by default (Bullet) is not extremely precise. It will
depend on what exactly you want to model.<br>
If you can provide more details, we can give you a better insight on
how to deal with this kind of sensors.<br>
<br>
Best regards,<br>
Gilberto Echeverria<div><div></div><div class="h5"><br>
<br>
On 06/06/2011 04:16 PM, Anna Chiara Bellini wrote:
</div></div><blockquote type="cite"><div><div></div><div class="h5">Dear all,<br>
<br>
I am working on a robot simulation project ( <a href="http://www.airobots.eu/" target="_blank">http://www.airobots.eu/</a> ) with
Blender and I am trying to do something which I'm sure someone else has
already done, so I'm asking for directions: I need to model passive
compliant joints and detect the forces acting on them. I guess that the
way is through Blender's rigid body joint constraint , possibly the
6DofSpringConstraint, but I'm not really sure about it and I really
don't know which would be the best solution.<br>
<br>
In our project, we are using MORSE for sensors/actuators/middleware, so
if anyone had a MORSE-specific solution or suggestion, that would be
great.<br>
<br>
Any ideas?<br>
<br>
Thank you in advance<br>
<br>
Anna Chiara Bellini<br>
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<pre cols="72">--
Gilberto Echeverria
Research Engineer
Robotics and Interactions Group (RIS)
LAAS/CNRS, Toulouse
+33 (0)5 61 33 78 95</pre>
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