FLL backup at route start

[joshsloat]

From some reading and discussions with teams at Worlds, it seems like a lot of FLL teams do a micro backup in the starting quarter circle against the wall to remove any potential slop in the drive motors. I just ran into the following example when reviewing Pybricks documentation.

This code seems like it might be the basis for a really good routine to run at the start of most missions since it:

• Resets the gyro (might have been jostled in placing the robot) and accumulated distance (which could be anything if you use something like a continuously running program with auto advancing menu)
• Performs the micro backup as described above

I am curious, though, about the approach used for backup vs just doing some fixed distance drive backward and hold, this code drives forever in reverse for 2 seconds and then stops with a coast. I would love to understand why and if that's a better approach for doing this micro reverse at the start of a run to remove potential drive motor slop and get things lined up better out of the gate.

Thanks!

[laurensvalk]

I am curious, though, about the approach used for backup vs just doing some fixed distance drive backward and hold, this code drives forever in reverse for 2 seconds and then stops with a coast. I would love to understand why and if that's a better approach for doing this micro reverse at the start of a run to remove potential drive motor slop and get things lined up better out of the gate.

The issue with a fixed distance can be that the wheels can block if they have a lot of grip, and then your robot just waits and sits there. You could also combine the two for less waiting overall.

[joshsloat]

Great suggestion. Thanks!