Wrong Field Measurements and Bad FMS

[Michael Hill]

To be perfectly honest, 1 inch sounds pretty reasonable. We have real design constraints and tolerances that you have to design your robot around. This isn't the "Perfect Physics world in a vacuum" where all measurements are spot on. They're close, but not perfect. The field is [mostly] held together with velcro, pins and zip ties. What do you expect?

[MarcD79]

As Field Supervisor at the Groton & Southington District plus Field reset at the Hartford District in Connecticut, I can tell you that the field definitely grew an average of 2-3 inches resulting in the classic folds on each end. In Groton the carpet was taped down on a brown craft paper. In Southington & Hartford the carpet was taped down on a vinyl rolled-out layer, which did stretch. As for being off an inch in the colored zones, I saw many robots shooting on the fly, so that "1 inch" was a moot point. If you are relying on being within 1 inch so you can shoot your ball, that takes too much time to line up & results in longer cycle times than someone who can just shoot as they fly down the field.

[Jay O'Donnell]

Originally Posted by Michael Hill

To be perfectly honest, 1 inch sounds pretty reasonable. We have real design constraints and tolerances that you have to design your robot around. This isn't the "Perfect Physics world in a vacuum" where all measurements are spot on. They're close, but not perfect. The field is [mostly] held together with velcro, pins and zip ties. What do you expect?

I expect people to put tape in the right place. Seriously an inch is honestly a pretty big deal for some teams. Why can't we put tape in the right spot? It's not that hard.

[RufflesRidge]

Originally Posted by Jay O'Donnell

I expect people to put tape in the right place. Seriously an inch is honestly a pretty big deal for some teams. Why can't we put tape in the right spot? It's not that hard.

The overall dimension of the field is specced as +4.0/-0in. and the tape is specced to trisect this area. This means that +1.33in. should be the tolerance for the size of each zone. Additionally the field and carpet stretching as mentioned by other posters above may cause additional deviation from this measurement that is very difficult for FIRST/event staff to do anything about.

If 1 inch honestly effects your autonomous:
1. You have a pretty solid PID running, it should be trivial for your team to tweak the value to fix your auto
2. It is unlikely your robot will score many goals in teleop this season unless you are using automatic positioning. A driver cannot achieve inch accurate positioning from 30+ feet away. Even with auto positioning any defense at all will cause a deviation of substantially more than an inch.

[Bryan Herbst]

Originally Posted by Jay O'Donnell

I expect people to put tape in the right place. Seriously an inch is honestly a pretty big deal for some teams. Why can't we put tape in the right spot? It's not that hard.

We can and should expect tape to be placed in the right spot. Unfortunately I think that part of this thread got lost amongst the unfounded FMS complaints.

It also wasn't clear whether the tape was incorrectly placed from the start, or whether the tape was placed correctly then appeared to be incorrect after a weekend full of matches.

This is an easy problem to deal with appropriately. As per section 5.5.7 of the manual, the field will be open for measurements for one hour at some point prior to practice matches starting. Go out on the field, take a look at the small details that you know will affect your robot, and point out any errors that are outside the tolerances to the Field Supervisor and/or FTA.