Integrating Computer Vision with Motion Control - FIRST Championship Conference

[Jared Russell]

Originally Posted by Ether

Do you know if the speaker will be fitted with an on-person mic that feeds electronically into the recorder?

Not sure, but I'll bring this up.

Originally Posted by jreneew2

When to use vision and when to not use vision. Last year, we had a mentor work on tracking the yellow totes for a couple of weeks and we didn't end up using it at all. :/

While this is not a strategy talk first and foremost, we will most certainly discuss this. In particular, we will look back at the history of vision in FRC and you will quickly notice how often the vision challenge is a diversion for the majority of teams.

[JesseK]

Mostly likely, I won't be able to attend the conference (either session at 7pm), but I do have a question and a few examples of what I mean.

What are some rules of thumb for the prerequisites to attempting vision?
- Great PID Control (fast settle, little/no overshoot) or "Good Enough" PID Control
- Level of precision on drive train turning or (auton) "drive straight" distance offsets
- For high-load situations, is a braking mechanism necessary

[dcarr]

Originally Posted by Jared Russell

While this is not a strategy talk first and foremost, we will most certainly discuss this. In particular, we will look back at the history of vision in FRC and you will quickly notice how often the vision challenge is a diversion for the majority of teams.

I think it's interesting that Stronghold seemed to present the "perfect storm" of factors that made vision a viable and extremely value asset for a larger-than-ever subset of teams.

Looking forward to this talk!

[Tom Bottiglieri]

I thought I'd share a clip we took today prepping for this conference presentation. We will definitely be going through all the pieces it takes to get a robot tracking like this!

[billbo911]

Tom and Jared, will you guys be discussing the realities of being able to process frames faster than the camera can produce them?

For example, a camera's maximum frame rate is listed at 30 frames per second, but your vision processing board can process over 80 frames per second.

[James Tonthat]

Too cool for school!

[marshall]

Originally Posted by Tom Bottiglieri

I thought I'd share a clip we took today prepping for this conference presentation. We will definitely be going through all the pieces it takes to get a robot tracking like this!

I didn't know you guys had ILM as a sponsor. I kid.

Seriously cool and I'm really looking forward to this talk now.

[billbo911]

Some additional questions.
What is the minimum frame rate you feel is acceptable for FRC?
How much lag is acceptable and how do you cope with it.
What is the most efficient way to get targeting data into the RoboRio (TCP, UDP, Serial etc.)?

[pmangels17]

I think it will be addressed, but I would be curious to hear exactly how much control on 254 is done by drivers vs with vision. What are your failsafes if the vision board suddenly crashes/shorts/explodes?

Also, what other sensors do you combine with vision for a more complete picture of your control system. For example, if you want to know distance to a target, are you using only a camera for that, or are there other sensors that you use to crosscheck your measurements.

And, specifically on your robot, how do you relay to the drivers that everything is in position for a shot? Is there a giant green check mark, does the system just not let you fire until it's ready, is the firing also controlled autonomously, or do you have a different solution?

[Jared Russell]

Originally Posted by pmangels17

I think it will be addressed, but I would be curious to hear exactly how much control on 254 is done by drivers vs with vision. What are your failsafes if the vision board suddenly crashes/shorts/explodes?

The operator holds a button saying they want to auto aim, and the driver holds a button saying that it's okay to shoot. Everything else is autonomous.

[JesseK]

Originally Posted by Jared Russell

The operator holds a button saying they want to auto aim, and the driver holds a button saying that it's okay to shoot. Everything else is autonomous.

Hmm - including sensing on the intake and ball pre-positioning?

[Jared Russell]

Originally Posted by JesseK

Hmm - including sensing on the intake and ball pre-positioning?

The intake also has some automation but no, I was speaking about the aiming and shooting subsystem.

[wesleyac]

Do you guys find that it's easier to accurately position the turret than it is to turn the drivetrain? That gif is really impressive, and I'm wondering how much of that is the turret being mechanically easier to control. Do you do any motion profiling on it, or is it just PID?

I'm looking forward to your talk!

[Jared Russell]

Originally Posted by wesleyac

Do you guys find that it's easier to accurately position the turret than it is to turn the drivetrain? That gif is really impressive, and I'm wondering how much of that is the turret being mechanically easier to control. Do you do any motion profiling on it, or is it just PID?

I'm looking forward to your talk!

The turret is just running position PID (onboard a CAN Talon SRX). Turrets are much easier to control than a drivetrain (inertia, friction, and skidding are basically non-issues).

[billbo911]

Originally Posted by Jared Russell

The turret is just running position PID (onboard a CAN Talon SRX). Turrets are much easier to control than a drivetrain (inertia, friction, and skidding are basically non-issues).

I assume you are using the camera to generate the set-point. Are you closing the loop with the camera as well, or are you using some other sensor like a gyro or encoder?