wpd's profile - activity

It seems like a new version of ros-galactic-example-interfaces was released today, version 0.9.2-2focal.20220430.122855, or possibly/likely one of its dependencies. And suddenly, my example code in a container (which fetches example-interfaces via rosdep install), no longer works. It produces the following error when I attempt to run it:

$ docker run -it --rm my/ros:app
Traceback (most recent call last):
File “/opt/ros/galactic/lib/python3.8/site-packages/rosidl_generator_py/import_type_support_impl.py”, line 46, in import_type_support
return importlib.import_module(module_name, package=pkg_name)
File “/usr/lib/python3.8/importlib/init.py”, line 127, in import_module
return _bootstrap._gcd_import(name[level:], package, level)
File “”, line 1014, in _gcd_import
File “”, line 991, in _find_and_load
File “”, line 975, in _find_and_load_unlocked
File “”, line 657, in _load_unlocked
File “”, line 556, in module_from_spec
File “”, line 1166, in create_module
File “”, line 219, in _call_with_frames_removed
ImportError: /opt/ros/galactic/lib/libexample_interfaces__rosidl_generator_c.so: undefined symbol: rosidl_runtime_c__double__Sequence__are_equal

I'm not sure whom I should inform. I see that a container built from the same Dockerfile a few days ago has version 0.9.2-2focal.20220210.222214 of ros-galactic-example-interfaces and that has been working fine for me all week.

--wpd

Add apt update && apt upgrade -y to the Dockerfile. I was certain that my Dockerfile had an apt update -y comma

Rebuilding doesn't work for me... at least, rebuilding the docker container that pulls in the prebuilt Ubuntu .deb files

Did ros-galactic-example-interfaces break? It seems like a new version of ros-galactic-example-interfaces was released

Blech... I spoke/wrote too soon. Any thoughts on how to integrate a 3rd party package that names itself sdbus-c++ in th

@flimsypondreed answered this in his comment above: If you create a ament-cmake package using the ros2 pkg create

@flimsypondreed answered this in his comment above: If you create a ament-cmake package using the ros2 pkg create

How to build and include a 3rd party library in a ROS2 package? I have source code for a library (and test application)

How to build and include a 3rd party library in a ROS2 package? I have source code for a library (and test application)

Given that my original question was a thinly veiled version of "I think I recall reading REP-119 once (perhaps 11 years

Is there anything that says "Thou shalt only use geometry_msgs/Twist on the /cmd_vel topic"?

Is there anything that says how a robot might indicate, "I have 2 wheels and can only move in the X direction or rotate about the Z axis"?

What should a robot do if it is commanded to move in the Y or Z axis and it is not capable of doing so? Should it halt and catch fire? Should it silently ignore such commands?

Oh yeah, how about some way to indicate "If you ask me to go 3e8 m/s, I'm not going to be able to achieve that. The best I can do is 1e-2 m/s, and that's only on a good day".

I feel like I read a REP about this once before, but all I'm seeing today is REP-103.

Thanks.

--wpd

Thanks. I missed REP-119. I am aware that there are "general conventions" about this, but thought it would make sense

Is there a REP or standard for the /cmd_vel topic? Is there anything that says "Thou shalt only use geometry_msgs/Twist

I just upgraded my VM from Ubuntu 12.04 to 14.04, and my ROS installation from Hydro to Indigo.

Now that I've done that, I wonder if there is anything special I need to do to migrate my catkin workspace (which was created initially with Hydro) to Indigo.

I just tried the obvious (I guess I could have tried this _before_ I asked my question, but the end result was about what I expected):

$ source catkin_ws/devel/setup.bash 
$ cd catkin_ws/
$ catkin_make
catkin_make: command not found

Hello @gvdhoorn, Thank you for the suggestion. Not knowing about the --skip-keys option, I instead went down the path o

This is funny. I am trying to do the same thing, 2 days after the OP (build melodic on a 16.04 machine). But it seems

This is funny. I am trying to do the same thing, 2 days after the OP (build melodic on a 16.04 machine). But it seems

I would like to build a ROS node that uses some code from an external project. I certainly need to reference some header files from that project, and will probably also need to "pull in" some C++ source code from that project.

The simplest, dumbest, least maintainable way I could to this would be to simply copy the header file(s) and source file(s) into my ROS project.

I feel like there should be some way to tell Catkin or Cmake "Add this directory to the list of includes" and "Add that directory to VPATH". But, as Catkin and Cmake are totally new to me (as of about a week ago), I haven't the foggiest idea how to ask the Google to find the answer to my question. So I'll ask the community instead :-)

Thanks for any tips you can give me.

According to REP 105, "The pose of a mobile platform in the odom frame can drift over time". I am trying understand what that means. In what situations would the frame "drift"? And "drift" relative to what? The base_link? How would the the odom frame drift relative to the base link if the robot is responsible for publishing the base_link->odom transform based on it's notion of odometry in the first place?

REP 105 also states/requires, "the pose of a robot in the odom frame is guaranteed to be continuous".

Does this mean I can't use an INDEX pulse on my wheel encoders to reset the axel angle to zero on each wheel rotation, since that might lead to a discontinuity? Or does it imply a requirement that I must filter my odometry estimates to eliminate such discontinuities.

Hmmm... maybe this starts to make sense. If I'm required (by REP 105) to eliminate any discontinuities, I can see where that might lead to "drift"...maybe.

Anyways, I'm confused, and would appreciate any enlightenment folks would care to give me on this topic.

--wpd