custom message error in ros2 with simulink

I made a custom message using the "ros2genmsg()" function in matlab and successfully made my custom message.

And when i test the message in simulink, i get an error message claiming

STD exception 'mwboost::wrapexcept<mwboost::exception_detail::current_exception_std_exception_wrapper<std::invalid_argument> >': 'Connection to process with Exchange: "5f1470ff-8f66-40e9-84fb-5f3bfd116a13 " was lost.' was caught.

I have no idea what i have missed here. When i use the provided message by matlab like "std_msgs" it works fine, but when i use my custom message, the simulink shows error shown above and likely breaks the simulink.

you can see from the picture below, my custom message "tire4_debug_msgs" is shown when i type ros2 msg list

I wanna know how i can fix this and make it right.

i'll give the the needed information for you guys if you leave a comment.

Thanks.

enviroment:

matlab R2022b

ubuntu22.04 / humble

Answer 1

[Prabeen Sahu]

Hi,

Thanks for helping in investigation. This issue might be due to an incompatibility between the libstdc++ shipped with MATLAB and the libstdc++ shipped with "Ubuntu 22.04 LTS".

Please try the following workaround:

1. Please rename libstdc++.so.6 file located in "matlabroot/sys/os/glnxa64" so that MATLAB cannot find it and is forced to use the system's version of the library. Renaming it to libstdc++.so.6.old should suffice. (where "matlabroot" is root installation directory of MATLAB).
2. Please delete the previously generated folders during ros2genmsg() execution and run reg = ros.internal.CustomMessageRegistry.getInstance('ros2',true); reg.refresh(true); to remove the existing ros2 custom messages.
3. Now please regenerate the custom messages using ros2genmsg() in R2022b MATLAB and check if you still face the issues.

-Pabeen

[준기 홍]

You made my day Prabeen, it worked!

I used my tier4_debug_msgs perfectly with no errors.

But i still have one question,

reg = ros.internal.CustomMessageRegistry.getInstance('ros2',true); reg.refresh(true);

when i run the command above i can still see my custom message using "ros2 msg list".

Is this just a glitch or can it be a real problem?

[Prabeen Sahu]

Hi,

Thanks for your confirmation.

To remove existing custom messages, 1st the generated folders should be deleted and then we have to run reg = ros.internal.CustomMessageRegistry.getInstance('ros2',true); reg.refresh(true).

-Prabeen

[준기 홍]

Thanks for your enormous help,

you made my project one step ahead. Thanks again and keep up the good work!

-J.K Hong

[Zalan Deutsch]

Hi!

I’ve had the same issue with R2023a, also on Ubuntu 22.04 LTS, and this solution worked for me too. However I’ve recently upgraded to R2023b, and I’m facing the same issue, but this solution is not working anymore. Do you have any other suggestions?

Thanks, Zalan

[Tobias]

Hi!

I'm also still having that issue with R2023b and Ubuntu 22.04 LTS, when trying to run or compile Simulink models with ROS2 subscribers that apparently use the code generation via this library.

The solution above didn't work for me either. Has anybody found another solution?

Best regards

Tobias

Answer 2

[Prabeen Sahu]

Hi,

please provide us with the following information:

1. What is the operating system that you are running your MATLAB on?
2. Are you experiencing this issue only with this particular custom message package or with any custom message?
3. Could you specify the exact moment when you encounter this issue? Is it when you select the topic or when you start running the model?
4. When you face this issue, please execute ros2 topic list in the MATLAB command window and verify if the topic appears in the list.
5. Do you encounter this issue when both the publisher and subscriber are in R2022b MATLAB ( Publish the messages using ros2publisher and subscribe them using ros2subscriber)?

Thanks,

Prabeen

[준기 홍]

Hi Prabeen Sahu, thanks for your interest.

1. My OS is Linux

2.Unfortunately i've not yet tried any other custom message

3.I do not encounter the error when i select the topic, the error occurs when i "run" the model

At first

STD exception 'mwboost::wrapexcept<std::runtime_error>': 'Transport stopped.' was caught.

this error shows up. And whenever i press run again

STD exception 'mwboost::wrapexcept<mwboost::exception_detail::current_exception_std_exception_wrapper<std::invalid_argument> >': 'Connection to process with Exchange: "5f1470ff-8f66-40e9-84fb-5f3bfd116a13 " was lost.' was caught.

this error message repeats.

4.Yes, the topic appears using the command "ros2 topic list" when i encounter the error.

5.I didn't used publisher and subscriber at the same time. I only used the subscriber block in simulink.

I used the subscriber block to subscribe a topic called "/control/trajectory_follower/lateral/diagnostic" and the message type this topic has is "tire4_debug_msgs/Float32MultiArrayStamped".

[Prabeen Sahu]

Hi,

Please run the below mentioned commands in MATLAB to clear the existing custom messages

reg = ros.internal.CustomMessageRegistry.getInstance('ros2',true);
reg.refresh(true);

Now please regenerate the custom messages using ros2genmsg() in R2022b MATLAB and check if you still face the issues.

If you still face the issues please use below mentioned code to create both publisher and subscriber in R2022b MATLAB and publish the messages using ros2publisher and subscribe them using ros2subscriber.

nod = ros2node("/testnode");
pub = ros2publisher(nod,"/control/trajectory_follower/lateral/diagnostic","tire4_debug_msgs/Float32MultiArrayStamped");
sub = ros2subscriber(nod,"/control/trajectory_follower/lateral/diagnostic");
msg = ros2message(pub);
pub.send(msg);
msg = sub.LatestMessage

Please check and inform us if you were able to receive the message(msg) without any problems. This testing will aid us in comprehending and pinpointing the issue.

Additionally, please specify which flavor of Linux you are using to run MATLAB.

-Prabeen

[준기 홍]

First of all my linux is Ubuntu 22.04 LTS (Jammy Jellyfish)

I followed the command line and seems like nothing happend.

reg = ros.internal.CustomMessageRegistry.getInstance('ros2',true);

reg.refresh(true);

Tried checking with "ros2 msg list" command but the custom message was still existing.

After this,

nod = ros2node("/testnode");

was succesful but I got stuck at

pub = ros2publisher(nod,"/control/trajectory_follower/lateral/diagnostic","tier4_debug_msgs/Float32MultiArrayStamped");

an error occurs like the picture below.

For the first attempt

Transport stopped.

error shows up terminating the command. And whenever i try again, the same error keeps appearing.

Connection to process with Exchange: "2401ef35-46cf-4c35-90b8-ceef4f75713d " was lost.

I also tried to regenerate my custom message after clearing the message you have noticed.

But regardlessly, got the same result.

Thanks for your help, appreciate it.

Answer 3

[Prabeen Sahu]

Hi,

Thanks for helping in investigation. This issue might be due to an incompatibility between the libstdc++ shipped with MATLAB and the libstdc++ shipped with "Ubuntu 22.04 LTS".

Please try the following workaround:

1. Please rename libstdc++.so.6 file located in "matlabroot/sys/os/glnxa64" so that MATLAB cannot find it and is forced to use the system's version of the library. Renaming it to libstdc++.so.6.old should suffice. (where "matlabroot" is root installation directory of MATLAB).
2. Please delete the previously generated folders during ros2genmsg() execution and run reg = ros.internal.CustomMessageRegistry.getInstance('ros2',true); reg.refresh(true); to remove the existing ros2 custom messages.
3. Now please regenerate the custom messages using ros2genmsg() in R2022b MATLAB and check if you still face the issues.

-Pabeen