G39 - Autonomus

[MARS_James]

I do not foresee this being an issue with my team, but I do think this will be fairly common and something to keep track of when scouting.

[JohnFogarty]

Quote:
Originally Posted by rich2202
I'll have to tell the programmers to check their position, and do not shoot if not in the right place.
This is harder than you think. Unless your vision system can accurately tell distance (and therefore derive your position on the field), there isn't much your programmers can do. Most defences like the Rough Terrain or Ramparts will render encoders basically useless until you're on flat ground again.

That being said, I think a lot of teams will get stuck on defences, or read their position inaccurately, during autonomous. However, some teams may have a way to mitigate this

Everyone's roboRIO has an accelerometer built into it.

If a team can't use that to tell the difference between being flat on the floor or sitting on a defense before firing... I will be very sad.

I might even go around at events making sure every team that plans on shooting, that our team would play with in quals at least, can utilize that feature to ensure no fouls.

[Jaci]

Originally Posted by JohnFogarty

Everyone's roboRIO has an accelerometer built into it.

If a team can't use that to tell the difference between being flat on the floor or sitting on a defense before firing... I will be very sad.

I might even go around at events making sure every team that plans on shooting, that our team would play with in quals at least, can utilize that feature to ensure no fouls.

Accelerometer =/= Gyro. Although 2 dimensions worth of data can be derived from the accelerometer, for most teams, this is not worth the effort. The RoboRIO's accelerometer has a lot of drift associated with it. This was also discussed Here

Even if a team decides to implement this, they still have to reorient to face the goal and shoot, for which they need to determine their distance and angle to the goal. If their vision is capable of this, it negates the need for a gyro in the first place.

[efoote868]

Originally Posted by Jaci

Accelerometer =/= Gyro. Although 2 dimensions worth of data can be derived from the accelerometer, for most teams, this is not worth the effort. The RoboRIO's accelerometer has a lot of drift associated with it. This was also discussed Here

Even if a team decides to implement this, they still have to reorient to face the goal and shoot, for which they need to determine their distance and angle to the goal. If their vision is capable of this, it negates the need for a gyro in the first place.

Drift only matters when you're double integrating for position. Using the accelerometer to determine which way is down will be very accurate.

[Caleb Sykes]

Originally Posted by efoote868

Drift only matters when you're double integrating for position. Using the accelerometer to determine which way is down will be very accurate.

It's not quite this simple to tell if you are stuck on a defense though. Teams can still be trapped on defenses when their robots are parallel to the floor. This will be very common on the moat, and could still happen with many other defenses.

[efoote868]

Originally Posted by Caleb Sykes

It's not quite this simple to tell if you are stuck on a defense though. Teams can still be trapped on defenses when their robots are parallel to the floor. This will be very common on the moat, and could still happen with many other defenses.

In that case, one could monitor the current going to the drive motors... if the drive wheels are spinning free they're not in contact with the carpet.

[Taylor]

We're mounting color sensors to the underbelly of our robot. We'll be watching for green, then not green, then green again.

[JacobD]

I don't necessarily see the accelerometer as a viable option for getting reliable data in autonomous unless you plan on only crossing defenses with level surfaces (unlike the moat or rough terrain). Otherwise, you will find that the inaccuracy of the accelerometer will hinder your tracking of positions on the field.

[notmattlythgoe]

Originally Posted by JacobD

I don't necessarily see the accelerometer as a viable option for getting reliable data in autonomous unless you plan on only crossing defenses with level surfaces (unlike the moat or rough terrain). Otherwise, you will find that the inaccuracy of the accelerometer will hinder your tracking of positions on the field.

Unless you just plan to use the accelerometer to sense when your robot has settled back down. Don't need to know you are flat, just need to know you are not moving all over the place.

[Daniel_LaFleur]

Originally Posted by efoote868

In that case, one could monitor the current going to the drive motors... if the drive wheels are spinning free they're not in contact with the carpet.

Yup, they can.

... another check before firing.
... another check most teams won't do

As the OP stated, there will be a number of G39s during autonomous.

[tr6scott]

Humm...
Forgot about the built in roborio...
Nothing but Navx...
#Pudding
https://youtu.be/l1z8WqELviA

[Andrew V]

We have developed a great way to tell if we made it to the other side of the outer works so we don't rely on encoders. Hint: The outerworks are a lot shinier than the carpet.