EuRoC Forum

[beaver]

Hello everyone,

I'm preparing the VM simclient for the final submission. Looking to the technical annex, I have to automatically launch my programs. Thus, if I have well understood, I should call services: /start_task3 & /start_task4.
In this way the simulations for task3 & task4 will start together in the simserver.
Is it the right procedure?

Regards,
Beaver

[MathieuG]

Hi Beaver,

You should start one task after the other, so call /start_task3, wait for task 3 to finish then call start_task4.

Best,
Mathieu

[beaver]

Thank you for your answer.
One more question: do you mean to do it manually or automatically?
Actually for the pre-final evaluation we have submitted a VM where: task 3 and task 4 wait the ros service call /start_taskX which need to be called manually.
Looking at the Technical Annex (last version) at pag. 33 it is not clear who has in charge the management of /start_taskX.

The final system delivered for final evaluation must fulfil some requirements:
- The contestants must provide two ROS nodes (one for each task) started automatically when
logging in simguest session on the controller client VM. Contestants can use and modify the
startup scripts in /home/simguest/Desktop to fire up their system.
- The nodes must be in a waiting state for the ready signals (see sample code in Section 2.6).
- The nodes must signal that they are starting solving a task/subtask to enable the scoring
system through the use of the appropriate ROS services (see sample code in Section 2.6).
- The nodes must also signal the end of tasks/subtasks through ROS services (see sample code
in Section 2.6).

Regards,
Beaver

[MathieuG]

You're right, it is not very clear.
It should be done automatically. For tests, simserv is launched then simclient is launched, then everything should run automatically.

Best,
Mathieu

[beaver]

If have well understood I have to:

1) automatically call /start_task3 at the startup of VM simclient
2) execute my code for task 3 (and related service for subtask)
3) call /stop_task3, little pause and consequently call /start_task4
4) execute my code for task 4 (and related service)
5) call /stop_task4

is right?

Beaver

[MathieuG]

Exactly. And you also have to set autologin.

Mathieu

[beaver]

Dear Mathieu, dear all,

we are launching automatically the task4 (/start_task4) at the end of the task 3 (after waiting ~30 seconds), but we obtain very strange behaviors (and sometimes gazebo crashes) at the begin the task 4.

Do you have some ideas about the solution this problem?

Beaver

[fry]

When starting task 4 after task 3, I experience rospy.exceptions.ROSInterruptException: ROS time moved backwards exceptions. Is that related to your problem?
My workaround is to completely shutdown all my rosnodes and roslaunch my stuff again from a bash script.

[beaver]

Dear Fry,
we don't receive this message (or similar messages), but the problem seems to be related with the "connection" of the second task with the roscore before the end of the previous one. So, a workaround can be to launch the second task's nodes after the end of the first one (for instance, by using a bash script).

Regards,

Beaver

[MathieuG]

Dear all,

For final evaluation, tests are going to be launch automatically. But in case the score doesn't reflect the one you received on the intermediate evaluation website, I will test it again manually.
Therefore, please upload your logfiles on the website so I can compare scores and put, for each task, a script on the desktop of your VM so I can easily launch it manually.

Best,
Mathieu