Chief Delphi - Minibot's triggering targets?

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Re: Minibot's triggering targets?

After having spent many hours acting as a high school swimming timer, I can tell you that this is a similar situation. There are "touch" pads at the end of the lane to automatically time the touch, there are people standing at the end of each lane with a manual trigger that is pressed when the swimmer touches, and there are two people with stopwatches that back-up the automatic system. Simple triple redundancy. If everything works, the touch-pads are the official score. The manual trigger is the backup for the touch-pads. In the event of a total system failure, the stopwatches are the official time.

Why not do something like that?

Re: Minibot's triggering targets?

For those of you insinuating small bots are not triggering, that was definitely not the case at FLR. The switches at the top of the pole are simple limit switches that deflect easily. The false positives during practice at FLR caused the field team to basically disable (I don't know what they actually did, but only one pole was really triggering) the tower finish lines. The mini bots traveling up the pole in 1.5 seconds or less have at least 10 times the energy required to trigger at the specified trigger force.

I am sure the system will get fixed, but the tower is definitely the problem right now.

Re: Minibot's triggering targets?

Quote:

Originally Posted by Paul Copioli (Post 1035403)

The mini bots traveling up the pole in 1.5 seconds or less have at least 10 times the energy required to trigger at the specified trigger force.

I am sure the system will get fixed, but the tower is definitely the problem right now.

We had a lot of issues triggering the poles at Kettering. Fortunately the Refs were reasonable about this, and there were only a few actual minibot races that there was a concern of which alliance got what place. The switch on our bot had a push force at 1.5X the maximum force specified in the manual. The bot itself builds up enough momentum to make the 10 foot steel pole on the practice field jump (not properly anchored) when it strikes. Force is definitely not the issue...

Re: Minibot's triggering targets?

The fault very much lies in the sensing equipment. I saw far more triggered by robots colliding with the the pole rather then minibots hitting the sensor.

Re: Minibot's triggering targets?

Quote:

Originally Posted by pitzoid (Post 1034993)

So FIRST FRC Engineering Ryan at the NJ regional has been playing around with the tuning all weekend trying to figure out what works best

Indeed, the sensors seemed to be working fine in practice, but appeared disabled for qualification rounds. They were fooling with them often during the days, but the manual system worked well.

Quote:

Originally Posted by R3P0 (Post 1035351)

TARGET design fail.

I don't think so. The minibots were easily hitting hard enough to trigger the switches, more than hard enough to overcome incidental friction from screw threads. My suspicion is the voting system "wasn't quite right". By the end some towers indicated consistently, but that left rear one never, ever did.

Re: Minibot's triggering targets?

Quote:

Originally Posted by Abrakadabra (Post 1035340)

According to this news report, the Finals at BAE GSR were actually contested due to this exact issue:

http://unionleader.com/article.aspx?...d-a4aac9a692ba

We were one of the the teams at BAE with a minibot that always climbed but never triggered the tower properly. We use a common Decora-style light switch on the top with hard physical stops on either side of it to protect the switch from being "crushed" into the plate when it hits the top. Our minibot definitely hits with the required force, but, as mentioned above, we suspect it may be the dwell time at the top that is the issue. The head of robot inspection came by our pits to specifically check our triggering setup on the minibot, and he said they were doing a survey of different triggering systems in an attempt to determine what did and did not work properly.

In any case, I would hope they figure this out quickly and fix it. The article above quotes an official as saying "We don't do video review here", but maybe that's something FIRST should actually consider.

I asked a ref about it at Traverse City, and he cited the "dwell time"; the programming for the field makes it so that the sensor plate doesn't trigger unless it is held for a short time (long enough that hitting the base won't trigger it). Ours triggered it because it held the sensor for a short time.

Re: Minibot's triggering targets?

Quote:

Originally Posted by TEE (Post 1035449)

Interesting design choice. If the FMS is handling that debounce routine, those are field faults: the sensor tripped and sent a signal (hence the tower has been triggered), and the FMS ignored it, because of an arbitrary timer with no basis in the rules. If, instead, the debounce is being handled on the sensor (so the FMS doesn't get a signal), then the fault lies in not accurately describing to everyone how the sensor actually works.

Ultimately, I think we've got to see a rule change and/or a design change, because it looks like the field is implemented in a manner that encourages field faults, and the only solutions available to the referees are by definition complete subjectivity with a large margin of error.