Frequently Asked Questions

General Troubleshooting

I can't see models in the Gazebo scene

You may need to download your models manually.

The models should be located in ~/.gazebo/models folder. If the models folder doesn't exist, just create this.

Go to this newly created folder cd ~/.gazebo/models and clone the following repository:

git clone https://github.com/osrf/gazebo_models.git

The files are saved in a folder named gazebo_models. Make sure everything in this directory is moved directly to ~/.gazebo/models.

You can do this by: cd ~/.gazebo/models mv gazebo_models/* .

Please note the models folder should now have the models in separate folders, e.g. your fire hydrant or cafe tables.

My script or the ROS package is not found

If you experience problems when running ROS problems, for example, it can't find a package, launch file, etc. You should try the following steps before anything else:

source ~/.bashrc

source ~/catkin_ws/devel/setup.bash

If this doesn't fix it, please take the following steps:

1. Check this page to see if it's been addressed already. We will be updating this page regularly as new issues arise.
2. Google for your error message or problem. Most things have been reported and fixed by others so use this information to help you. Make sure you check that the fix is relevant to your setup, e.g. ROS versions, specific packages etc. If in doubt, please ask us to check it over.
3. Ask your team if they have had similar problems and can help advise. Often your team mates will have been through a similar journey with their work and can help you out or even work together to find a suitable solution to the problem.
4. Post a message in your team channel with details of the problem you are experiencing. Try to provide us with a synopsis of the problem and the steps you have taken to try and resolve it. Once you have posted it, please flag the support team in Computing and Practicals team channel letting us know that you have a problem and which Team channel you are in.

I have a while loop where I check the duration, however the loop is never entered

This only happens when working in the Simulation, where sometimes the clock does not start in due time. You can avoid this situation by putting a sleep() call after initialising your node.

Environmental Setup

When I launch Gazebo I get an ignitionfuel.org error.

If you see the following error when launching Gazebo: libcurl: (51) SSL: no alternative certificate subject name matches target host name 'api.ignitionfuel.org' ; You should follow this guide: https://varhowto.com/how-to-fix-libcurl-51-ssl-no-alternative-certificate-subject-name-matches-target-host-name-api-ignitionfuel-org-gazebo-ubuntu-ros-melodic/

Azure Virtual Machines

I can't login to my Azure Virtual Machine

Make sure you are using the user labuser and not your Nottingham username. Also, please try resetting your password via the Azure labs website by clicking on the 3 dots next to your machine and following the Reset Password instructions.

I'm having browser issues on the virtual machine.

Some instances of Azure have seen problems with the default web browser. If you experience any issues, it is recommended that you install Firefox using sudo apt install firefox.

Gitlab

I don't have access to Gitlab

Contact [email protected].