
A joint
in your urdf defines the transform between two link
s, which are represented in your TF tree as frames.
So a revolute joint joint_1
between link_1
and link_2
for which JointState
messages are being published will cause robot_state_publisher
(in this example) to update the relative pose of link_2
wrt link_1
based on the transform specified by the origin
tag of joint_1
. Rotation will be around the origin of link_1
(plus or minus some offset specified by the joint
).
Is a joint in a URDF considered a frame in the TF library?
So I believe the answer would be "no, but link
s are".
Edit: note that the origin
element in your urdf specifies the transform between link
s with the robot in it's zero pose. Afterwards those transforms are updated based on JointState
messages.
Originally posted by gvdhoorn with karma: 86574 on 2018-03-27
This answer was ACCEPTED on the original site
Post score: 3
Original comments
Comment by MechLc on 2018-03-27:
Oh! makes sense! Thank you so much!
Edit:
rosrun tf view_frames
confirms it