I would like to use sensor descriptions on urdf_model.

I write proposals for extended sensor element of urdf ( http://wiki.ros.org/urdf/XML/sensor/proposals ).

It's based on SDFormat( http://sdformat.org/spec?ver=1.5&elem=sensor ). 

Some discussion already have here ( https://github.com/ros/urdfdom/pull/28 )

Please review proposals and send feedbak.

Thanks in advance.