[FTC]: Motor encoders Love'em? or leave'em?

[aakerberg]

Well, accurate distance isn't all that important. Presumably you should have some opportunity to tune your program to account for any inaccuracy in the encoder. However, consistent results ARE important. A better experiment would be:

1. Mark a very specific start point
2. Program the robot to go any distance
3. Mark where it finishes moving.
4. Repeat several times - preferably with different loads (add/subtract weight) and/or different levels of battery charge.

How close does it get to your original finish mark each time? if the encoders are reasonably consistent, you should end up in the same spot (or very close) each time, regardless of load or battery condition.

The problem with using encoders for measuring robot position in autonomous mode is they offer no defense against the things that are most likely to trip you up - getting bumped off course by another robot, wheels slipping on the edge of the board, etc.. I would argue that provided you don't make radical changes to the robot during the course of a single competition and manage your battery pack properly, you can get equally effective results using time for judging distances driven.

If they are consistent, I can see them being more useful for measuring things like precision arm movements, or maybe feedback for a sophisticated driving control system...

We have been also been unhappy with they way they are mounted to the outside of the motor. We are experimenting this year with other ways to give us the information we need.