paper: Team 341 Vision System Code

[Ziv]

Originally Posted by sebflippers

Thanks for the code. I believe lines 322-334 [snipped] could be replaced with

private double boundAngle0to360Degrees(double angle)
    {
        return(abs(angle)%360.0);
    }

Consider the angle -90. Daisy's code returns 270, but yours returns 90. I think you're looking for something more like this:

private double boundAngle0to360Degrees(double angle)
    {
        double ret = abs(angle)%360.0;
        if(angle < 0.0)
        {
            ret = -ret;
        }
        return(ret);
    }

[sebflippers]

Originally Posted by Ziv

Consider the angle -90. Daisy's code returns 270, but yours returns 90. I think you're looking for something more like this:

private double boundAngle0to360Degrees(double angle)
    {
        double ret = abs(angle)%360.0;
        if(angle < 0.0)
        {
            ret = -ret;
        }
        return(ret);
    }

right.

[sebflippers]

done. This one kind of defeats the purpose of making your code simpler, though.

	public static double boundAngle0to360Degrees(double angle)
    {
        return(angle > 0.0? angle % 360.0 : 360.0*(1 + (Math.abs((int)angle)/360))+angle);
    }

[Gray Adams]

Originally Posted by sebflippers

done. This one kind of defeats the purpose of making your code simpler, though.

	public static double boundAngle0to360Degrees(double angle)
    {
        return(angle > 0.0? angle % 360.0 : 360.0*(1 + (Math.abs((int)angle)/360))+angle);
    }

Why not just...

 public static double boundAngle0to360Degrees(double angle)
    {
        return((angle+360)%360);
    }

[Jared Russell]

Originally Posted by Gray Adams

Why not just...

 public static double boundAngle0to360Degrees(double angle)
    {
        return((angle+360)%360);
    }

What if angle is equal to -361?

It's awesome that you guys are analyzing the code and you have already taught me something new (that Java's "%" operator works on floating point values...as a primarily C++ guy, I have it burned into my brain that thou shalt use "fmod" for floating point modulus). But if this is the part of the code that engenders the most discussion, then I'm a bit disappointed

[Gray Adams]

Originally Posted by Jared341

What if angle is equal to -361?

It's awesome that you guys are analyzing the code and you have already taught me something new (that Java's "%" operator works on floating point values...as a primarily C++ guy, I have it burned into my brain that thou shalt use "fmod" for floating point modulus). But if this is the part of the code that engenders the most discussion, then I'm a bit disappointed

Ok, fine.

return(((angle%360)+360)%360);

[AlexD744]

I feel like at this point the original code was easier to understand from an outside perspective.

On another note, this is AWESOME! It's nice to see another team using Java to program, especially when it's done so well. Our camera tracking system is currently only used in auton to track after grabbing the third ball off the co-op bridge. It's very rudimentary code so that it can be run on the cRio (we had issues with a bad camera that made it impossible to test any sort of laptop based vision code). This is very interesting, and I'm excited to go over it in more detail later.

[Tom Bottiglieri]

Thanks for posting this, Jared. I took a look at your dashboard on the field at Champs and was very impressed. It seems incredibly useful to have the vision system draw its idea of target state on top of the real image.

I suspect if vision is a part of upcoming games, we will probably use a solution very similar to this. This year we wrote all of our vision code on top of WPILib/NIVision to run on the cRIO. In the end we got this to work pretty well, but development and debugging was a bit of a pain compared to your system.

[Leeebowitz]

Very cool! I just finished taking an online data structures course from IIT, so it was really awesome to see the implementation of the TreeMap! Just so that I'm sure I understand, it is used to quickly find an rpm based on your distance, right? What are the advantages (if any) of using this instead of plugging your data points into an excel graph and getting a polynomial best fit equation to transform your distance into an rpm?

[Jared Russell]

Originally Posted by Leeebowitz

Very cool! I just finished taking an online data structures course from IIT, so it was really awesome to see the implementation of the TreeMap! Just so that I'm sure I understand, it is used to quickly find an rpm based on your distance, right? What are the advantages (if any) of using this instead of plugging your data points into an excel graph and getting a polynomial best fit equation to transform your distance into an rpm?

The biggest advantage was it made tuning very easy. Take the bot to the practice field with some balls, fire away, and record the range/RPM information into the TreeMap if you like what you saw (we actually had a version of the software that let the operator do this with the push of a "commit" button, but we ended up doing it all by hand just to sanitize the values). No need to fire up Excel.

[Jared Russell]

Originally Posted by Tom Bottiglieri

I suspect if vision is a part of upcoming games, we will probably use a solution very similar to this. This year we wrote all of our vision code on top of WPILib/NIVision to run on the cRIO. In the end we got this to work pretty well, but development and debugging was a bit of a pain compared to your system.

By far the biggest advantage of a laptop-based solution was the development process that it facilitated. Simply collect some representative images and then you can go off and tune your vision software on a laptop without needing a cRIO or the FRC control system.

[JamesTerm]

Originally Posted by Jared341

What if angle is equal to -361?

It's awesome that you guys are analyzing the code and you have already taught me something new (that Java's "%" operator works on floating point values...as a primarily C++ guy, I have it burned into my brain that thou shalt use "fmod" for floating point modulus). But if this is the part of the code that engenders the most discussion, then I'm a bit disappointed

Doh! I missed this before I responded as it was on the 2nd tab...

While I'm here though... if you are a c++ guy why use Java? Is it because it was the only way to interface with the dashboard? I gave up when trying to figure out how to do that in wind river.

[Jared Russell]

Originally Posted by JamesTerm

Doh! I missed this before I responded as it was on the 2nd tab...

While I'm here though... if you are a c++ guy why use Java? Is it because it was the only way to interface with the dashboard? I gave up when trying to figure out how to do that in wind river.

Easy, it's because I am not the only person who writes software for our team! Java is what is taught to our AP CS students, and is a lot friendlier to our students (in that it is a lot harder to accidentally shoot yourself in the foot). I also have a lot of training in Java (and still use it on a nearly daily basis), even if C++ is my bread and butter.

[JamesTerm]

Originally Posted by Jared341

Easy, it's because I am not the only person who writes software for our team! Java is what is taught to our AP CS students, and is a lot friendlier to our students (in that it is a lot harder to accidentally shoot yourself in the foot).

Ah ok.

Originally Posted by Jared341

But if this is the part of the code that engenders the most discussion, then I'm a bit disappointed

Don't be disappointed... this discussion has taught/reminded us something that we rarely use in c++, and this discussion indirectly helped my co-worker fix a bug today. I do know how you feel though as there is a *lot* of effort that goes into this! I had most-all my vision code written as well, and unfortunately it is all going straight into the bit bucket, as we could not get the deliverables to make it work in time. I do want to look your code over in more detail and post what I did as well, and hopefully at that time the discussion will have more meat in it as I do want some closure in the work that I have done thus far.

I will reveal one piece now with this video:
http://www.termstech.com/files/RR_LockingDemo2.mp4

When I first saw the original video, it screamed high saturation levels of red and blue on the alliance colors, and this turns out to be true. The advantage is that there is a larger line to track at a higher point as I could use particle detection alone. The goal then was to interpret the line to perspective and use that to determine my location on the field. From the location I had everything I needed as I then go to an array table error correction grid with linear interpolation from one point to the next. (The grid among other tweaks are written in LUA more on that later too).

more to come...

There is one question that I would like to throw out there now though... Does anyone at all work with UYVY color space (a.k.a YPbPr). We work with this natively at NewTek, and it would be nice to see who else does.

[Bryscus]

So after attending the Einstein Weekend debugging session this past weekend and chatting with some of the teams about their various OpenCV implementing vision systems, I just HAD to check out Daisy's code (another suggestion from Brad Miller).

So honestly, I have little experience with Java but figured what the heck since it's so close to C++. After following some of the Getting Start Guides and playing with a couple of projects, I downloaded Daisy's code and set to work running main() and passing the example image paths to the code as arguments. This seems to work well and two windows pop up showing the "Raw" and "Result" images. What baffles me is that I get this as output as well:

"Target not found
Processing took 24.22 milliseconds
(41.29 frames per second)
Waiting for ENTER to continue to next image or exit..."

and for the "Result" image I get a vertical green line more or less in the middle of the picture. I ran the program a couple of times with different images and similar results? Can someone tell this C guy what the heck he's doing wrong? Is there something I'm missing? If you guys (Daisy) were using a different color ring light or something, could you provide some sample images that work? Thanks in advance!

- Bryce

P.S. I'm running this on an OLD POS computer running XP and a Pentium D processor. I'll have to run it at home on something with a little bit of muscle and check performance.