What information can we access from the camera?

[Total Meltdown]

What information do we have access to regarding the camera? I heard about Height of the target, angle from the robot to said target, etc. What other information is returned?

[fowlerm]

Originally Posted by Total Meltdown

What information do we have access to regarding the camera? I heard about Height of the target, angle from the robot to said target, etc. What other information is returned?

You can get all that along with motion tracking using the IFI CMUcam not the Google digital camera. The Google camera is ment only to take pictures of your robot and upload them as a "photo essay".

[Elgin Clock]

I think you are a bit confused.

Google was announced as a sponsor of FIRST last year, and so the camera in the kit is a digital camera for taking pictures donated by Google for all teams to document their build/team progress.

The camera which is going to be on robots, is the return of 2005's CMU Cam system.

This is used for defining the green color, and going to be used for the purposes you are thinking of.

Originally Posted by fowlerm

You can get all that along with motion tracking using the IFI CMUcam not the Google digital camera.

The CMU Cam was made by Carnegie-Mellon University (CMU) and is not an IFI part. I think your confusion is because IFI handles the ordering of the CMU cameras. (If I'm not mistaken)

[Ken Leung]

I just edited the thread title, correcting the confusion between the Google ditigal camera and the CMU camera. Hopefully that will clear things up and provide the right answer for the person who asked the question.

[Elgin Clock]

Originally Posted by Ken Leung

I just edited the thread title, correcting the confusion between the Google ditigal camera and the CMU camera. Hopefully that will clear things up and provide the right answer for the person who asked the question.

I was wondering who did that. Thanks Ken.

[fowlerm]

Originally Posted by Elgin Clock

The CMU Cam was made by Carnegie-Mellon University (CMU) and is not an IFI part. I think your confusion is because IFI handles the ordering of the CMU cameras. (If I'm not mistaken)

The camera we get in the kit is an IFI manufactured part. They licensed it from Carnegie-Mellon.

[Total Meltdown]

Yes, sorry, I meant the IFI camera, not the Google one.

We're developing a system for auto-tracking the top goal autonomously, so that our "gun" will always be pointing at the correct angle to fire the ball into the goal, using some basic laws of projectile motion. I'll make a thread about it if the team decides they like it and it goes anywhere.

[Kevin Watson]

Originally Posted by Total Meltdown

We're developing a system for auto-tracking the top goal autonomously, so that our "gun" will always be pointing at the correct angle to fire the ball into the goal, using some basic laws of projectile motion.

This is precisely what I (and others) hope teams will do this year. I'm writing a one page white paper on computing range, which I'll post soon. Basically, range = (green light height - camera height)/tan(tilt angle), where green light height equals 10' 10", camera height is the distance the camera is mounted above the floor and tilt angle is the calculated tilt angle derived from the tilt PWM value when the tracking software has a good solution. I've posted the camera software Dave Lavery mentioned here: http://kevin.org/frc

-Kevin

[Total Meltdown]

Yeah, I could compute the distance if I need to, but I thought I heard them say that the distance was already returned right in the camera code itself.

...and would I be safe in assuming that the robot controller can do the basic Trig functions? Sin Cos Tan and the like?

[Kevin Watson]

Originally Posted by Total Meltdown

Yeah, I could compute the distance if I need to, but I thought I heard them say that the distance was already returned right in the camera code itself.

...and would I be safe in assuming that the robot controller can do the basic Trig functions? Sin Cos Tan and the like?

The current revision of the code does not give you range (I'll add this on the next rev.), but if you look at the code in terminal.c, you'll see how to calculate the tilt angle, which gets plugged into the equation mentioned above. Yes, the compiler has math.h support.

-Kevin

[Total Meltdown]

Balls are scooped in between the front wheels, being shuffled toward 
the "Wheel" which works like an automated Baseball pitcher.

Front                                Back
                   \
                    \
            \        \  <-- Turret swivels 360
             \        \     Degrees, and tips from
              \        \    Straight up to about 30 degrees
|-------------------------------------|
|   Wheel   --> ()     /<-- Ball      |
| (not to scale)      / scooper brings|
| shoots balls up    / balls to turret|
| the barrell       /  base           |
|-------------------------------------|

...yes, I just made an ASCII diagram of my robot design.

What I was thinking, is that the program constantly calculates the launch vector based on the speed at which the mechanism launches balls, and rotates and tilts the turret. I'm taking Physics now and we've already gone over Projectile motion, so it shouldn't be too hard to figure out the Angle at which the turret has to be positioned based on how far away you are from the goal.

Note that this design requries that the ball be fired at the same speed every time, or have some way to determine how fast the ball will be fired.

[devicenull]

So far, I intend to mount the camera next to the launcher. This way, as long as I mirror the up/down motion of the camera, the laucnher should be always aiming correctly.

Does anyone know if we got the mount for the camera they used at the kick off, or if the plans are available for it.. it's a lot nicer then the one we used last year.

I find it nice we have a physics teacher as one of our mentors

[seanwitte]

Attached is a Windows app for version 2.0 of the .NET framework that I used when I reviewed the camera code last month. The app will display what the robot thinks its seeing and the values for the pan and tilt servos. Directions for sending the data are included in the zip file. Extract the exe and the dll to the same folder and run it.

[Justin Stiltner]

devicenull,
Yes we recived the pan/tilt unit that was shown at kickoff, it should be in your electronics box in a bag marked frc-pantilt-01, I have not yet found directions on how to assemble the camera, but will be making some and posting them if noone beats me to it.

[seanwitte]

Originally Posted by seanwitte

Attached is a Windows app for version 2.0 of the .NET framework that I used when I reviewed the camera code last month. The app will display what the robot thinks its seeing and the values for the pan and tilt servos. Directions for sending the data are included in the zip file. Extract the exe and the dll to the same folder and run it.

It looks like the x and y bounds in the application are wrong and should be reversed. It will still track and display fine, but the x axis is too long and the y axis is too short. I will make the correction and re-post if anyone is actually using it.