/usr/share/sdformat/1.3/imu.sdf is in sdformat-sdf 2.0.0-6.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 | <element name="imu" required="0">
<description>These elements are specific to the IMU sensor.</description>
<element name="topic" type="string" default="__default_topic__" required="0">
<description>Topic on which data is published.</description>
</element>
</element>
|