Incorrect order of joints using ROS Humble

[IvoD1998]

Hello

When trying to use the joint states of the robot for a forward kinematic calculation, we noticed that the order of the joint positions seems to be published incorrectly.
It appears that the order of joints is now published as:

• joint1
• joint2
• joint5
• joint3
• joint4
• joint6

(see screenshot below for added clarity)

Thank you in advance!
Ivo Dekker

[clalancette]

Can you please describe why that is wrong, and how joint_state_publisher is involved here?

[IvoD1998]

We were wondering why the list of joints as published by the joint state publisher does not match the sequential order they are supposed to be in according to the robot URDF. We tested this with various different robot models and got the same result.
It could of course also be an issue on the side of the MoveIt configs for the robots, but we are uncertain.

[karanchahal]

Can I use foxglove to do this ? What do I need to do ?

[sloretz]

It looks like there is an intent to publish the joints in a fixed order:

joint_state_publisher/joint_state_publisher/joint_state_publisher/joint_state_publisher.py

Line 344 in 424fd9e

for i, name in enumerate(self.joint_list):

Mind posting a urdf that shows the issue? It might be the change in order came from the urdf parser, as that's where joint_state_publisher gets the order from

joint_state_publisher/joint_state_publisher/joint_state_publisher/joint_state_publisher.py

Lines 87 to 98 in 424fd9e

	def init_urdf(self, robot):
	robot = robot.getElementsByTagName('robot')[0]
	# Find all non-fixed joints
	for child in robot.childNodes:
	if child.nodeType is child.TEXT_NODE:
	continue
	if child.localName == 'joint':
	jtype = child.getAttribute('type')
	if jtype in ['fixed', 'floating', 'planar']:
	continue
	name = child.getAttribute('name')
	self.joint_list.append(name)