  With the increasing complexity of robot systems, it is necessary to simulate
them before deployment. To do this, a model of the robot's kinematics or
dynamics is required. One of the most commonly used formats for modeling robots
is the Unified Robot Description Format (URDF). The goal of this article is to
understand how URDF is currently used, what challenges people face when working
with it, and how the community sees the future of URDF. The outcome can
potentially be used to guide future research. This article presents the results
from a survey based on 510 anonymous responses from robotic developers of
different backgrounds and levels of experience. We find that 96.8% of the
participants have simulated robots before, and of them 95.5% had used URDF. We
identify a number of challenges and limitations that complicate the use of
URDF, such as the inability to model parallel linkages and closed-chain
systems, no real standard, lack of documentation, and a limited number of
dynamic parameters to model the robot. Future perspectives for URDF are also
determined, where 53.5% believe URDF will be more commonly used in the future,
12.2% believe other standards or tools will make URDF obsolete, and 34.4% are
not sure what the future of URDF will be. Most participants agree that there is
a need for better tooling to ensure URDF's future use.
