Chapter 4 Quiz not end as expected mark 7.0

Course Support ROS2 Basics in 5 Days (Python)
1

Hi,

the server creates this log

[services_quiz_server-1] [INFO] [1669053400.427494336] [turn_server]: req direction Turn Right velocity 0.2 time 10
[services_quiz_server-1] [INFO] [1669053400.428299051] [turn_server]: Turning to right direction!!
[services_quiz_server-1] [INFO] [1669053400.428992002] [turn_server]: Interval Start 2022-11-21 17:56:40
[services_quiz_server-1] [INFO] [1669053410.001020483] [turn_server]: Interval Stop 2022-11-21 17:56:50

when launching the client so in theory it should be as requiered

    • It will spin to the right.
    • It will spin at an angular velocity of 0.2 rad/s.
    • It will spin during 10 seconds.

any hint why it should not pass the test ?

Regards

2

Hi @vkuehn ,

Could you please post a picture of your error message that the Gradebot / Autograder generated?
That would be an easy way to find a solution to your problem.

– Girish

3

Hi @girishkumar.kannan ,

it says

...
âś” [info] Checking that the robot performs the expected turn... (mark: 7.0)

âś– [assess] The robot did NOT fully perform the expected turn. Things your can check:
- Did the robot turn as indicated in the notebook?
- Did the robot complete the turn within the stipulated time? (mark: 7.0)

Does this shed some light ?

Regards

4

Hi @vkuehn ,

Thanks for posting the error info.

The two checks for validating the “turn” seems straightforward.
I believe you have done it and verified it by testing your code (as posted on your earlier / initial post).

At this point, I have no suggestions for a solution and you must check with The Construct team to provide you a solution.

Regards,
Girish

5

Thanks @girishkumar.kannan

6

Hello @vkuehn ,

Looking at the logs, the problem is with the final orientation of the robot when it finishes the rotation. The final expected orientation is more or less 90 degrees to the right (as shown in the GIF of the resulting motion). Does your robot end in a similar orientation? Could you check the orientation quaternion of the robot when your motion finishes (you can check it on the /odom topic)?

7

Hello @albertoezquerro,

thanks.
I did miss the point that the turn messages should allow the angular speed equals zero.
But when moving 10 second with the speed 0.2 the rotation is not 90 degrees.

start z: -0.0002586989728542422
0.2 z: -0.5181289083644276
0.3 z: -0.9343995303966297

speed 0.3 would be almost 90 degree is that right to pass the test ?

8

Yes, after the 10 seconds pass, the robot has to stop. Then, the final orientation of the robot is evaluated. If this orientation is close to 90 degrees (it allows an error threshold), the Quiz should pass. Let me know if it doesn’t.

9

@albertoezquerro,

no doesn’t pass !
as mentioned above the rotation speed should be correct(tried 0.2 and 0.3) but rotates not close enough.

10

Hello @vkuehn ,

I did some adjustments to the correction script. Could you please try to correct it again?

1 Like
11

Hello @albertoezquerro,

thanks a lot ! that did the trick !

Kind Regards

12

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