joint_state_publisher not starting

[cpetersmeier]

Hello,

I am unable to use the moveit commander cmd line, because the joint_state_publisher doesnt start properly.
In my launch file I call

<node name="joint_state_publisher" pkg="joint_state_publisher" type="joint_state_publisher">
<param name="use_gui" value="true"/>
<rosparam param="source_list">[move_group/fake_controller_joint_states]</rosparam>
</node>

When executing the launch file I get this error:

Traceback (most recent call last):
File "/opt/ros/melodic/lib/joint_state_publisher/joint_state_publisher", line 474, in <module>
jsp = JointStatePublisher()
File "/opt/ros/melodic/lib/joint_state_publisher/joint_state_publisher", line 149, in __init__
robot = xml.dom.minidom.parseString(description)
File "/usr/lib/python2.7/xml/dom/minidom.py", line 1928, in parseString
return expatbuilder.parseString(string)
File "/usr/lib/python2.7/xml/dom/expatbuilder.py", line 940, in parseString
return builder.parseString(string)
File "/usr/lib/python2.7/xml/dom/expatbuilder.py", line 223, in parseString
parser.Parse(string, True)
UnicodeEncodeError: 'ascii' codec can't encode character u'\xb0' in position 4420: ordinal not in__range(128)

and

[joint_state_publisher-4] process has died [pid 5986, exit code 1, cmd /opt/ros/melodic/lib/joint_state_publisher/joint_state_publisher
__name:=joint_state_publisher
__log:=/home/chris/.ros/log/a08dc708-8dca-11e9-9608-000c2908badd/joint_state_publisher-4.log].
log file: /home/chris/.ros/log/a08dc708-8dca-11e9-9608-000c2908badd/joint_state_publisher-4*.log

This is all in an rviz context, and the gui and the rest of moveit loads fine.
Can anyone help me resolve this issue?

[gavanderhoorn]

I'm unsure how this is related to the Fanuc packages here.

Can you clarify?

[gavanderhoorn]

And please use verbatim formatting for xml and console copy-pastes (ie: three consecutive backticks).

[cpetersmeier]

Of course,
so I got this error while trying to launch the test.launch file provided by the fanuc packages

[gavanderhoorn]

so I got this error while trying to launch the test.launch file provided by the fanuc packages

please be specific: which file.

Provide steps to reproduce, otherwise we cannot help you.

[cpetersmeier]

Okay, I am sorry for my unclear explanation.

I am working on adapting the fanuc packages for the 35kg variant of the m20ia robot.

What I did:

Create a URDF / XACRO file for the robot.
Create a MoveIt Config.
Created the 4 launch files, described here

When do I get the error?
When launching the...

• adapted test_m20ia.launch file (note: appears to not load the origin and material tags correctly)
• demo.launch file created by the moveIt setup assistant (note: loads correctly)

When starting the test_m20ia.launch file from the offical ros-i fanuc packages, everything works fine.

I am wondering if I missed a step in my launch file, or moveit configuration. The other nodes, such as the moveGroup and Planning Scene provided by moveIt start just fine. That is why I thought it would maybe be an issue with a thing I missed in adapting the packages.
I followed the syntax and naming schemes of the offical packages as close as possible.

[gavanderhoorn]

It's difficult to help you without seeing your files, but I would first check whether you're not running into locale issues, seeing as you're German, using Ubuntu Bionic/ROS Melodic and most likely using a German locale.

Refer to ros/urdfdom_headers#45.

[cpetersmeier]

Thanks for the hint! I'll try and dig deeper there.
When I run

$ locale

the output I get is

LANG=en_US.UTF-8
LANGUAGE=
LC_CTYPE="en_US.UTF-8"
LC_NUMERIC="en_US.UTF-8"
LC_TIME="en_US.UTF-8"
LC_COLLATE="en_US.UTF-8"
LC_MONETARY="en_US.UTF-8"
LC_MESSAGES="en_US.UTF-8"
LC_PAPER="en_US.UTF-8"
LC_NAME="en_US.UTF-8"
LC_ADDRESS="en_US.UTF-8"
LC_TELEPHONE="en_US.UTF-8"
LC_MEASUREMENT="en_US.UTF-8"
LC_IDENTIFICATION="en_US.UTF-8"
LC_ALL=

[gavanderhoorn]

That looks ok.

The problem is most likely this:

UnicodeEncodeError: 'ascii' codec can't encode character u'\xb0' in position 4420: ordinal not in__range(128)

\xb0 is (according to this site) a Unicode Character 'DEGREE SIGN'.

It's likely that you copy-pasted joint limits from a PDF and added a degree sign somewhere.

You'll have to check your xacro macro.

[gavanderhoorn]

As this is not a problem with any of the packages in this repository, I'm going to close the issue.

Feel free to keep commenting on it though, @cpetersmeier.

[cpetersmeier]

That solved the issue! Thank you very much for the fast help!

For reference, here is a detailled description of the solution:

In the .XACRO file I commented the joint limits for reference with a degree sign:
<limit lower="-4.712389" upper="4.712389" effort="0" velocity="6.98" />
<!-- <limit lower="-450°" upper="450°" effort="0" velocity="6.98" /> -->

Removing the degree sign in the comments solved the issue for me:
<!-- <limit lower="-450" upper="450" effort="0" velocity="6.98" /> -->

[gavanderhoorn]

I would recommend to use the support in xacro for Python expressions.

That would allow you to do something like this:

<limit lower="${radians(-450)}" upper="${radians(450)}" effort="0" velocity="..." />