Re: Where is the multi object tracking code for the RC?
 

We're currently looking at a number of things. Of particular interest to us is the relationship between the location of the centroid and the locations of the top-left and lower-right corners. We're hoping to use the fact that the centroid is closer to the light with a smaller angle to the robot in order to write a function that takes those three locations and tells us enough about where the lights are to either lock-in on one of them or on the middle.

-Guy

Re: Where is the multi object tracking code for the RC?
 

We are in a similar situation, and I was hoping to begin camera work this week. Kevin, I'm actually glad that you've decided not to release your camera code right away and have instead just gently prodded (:D) us in the right direction. Though your code is phenomenal and a big help, it has been a lot of fun this year to try to figure out some possible alternative solutions (especially for such an interesting problem).

To all the people who have proposed methods other than the one used by the EasyC code: would you care to share any test results or code for those methods? It would be very time consuming for everyone to test every method for its viability, so perhaps some collaboration would be useful.

I'll try to post some LabView Code and C source if I can test the VW thin-slicing method soon. Thanks again to Kevin and everyone else's input on this topic

Re: Where is the multi object tracking code for the RC?
 

Well, it's not like I wasn't/haven't been thinking about this. I only asked because I was about to start hardcoding and wanted to know if I should wait. It would be stupid to code up a whole solution if I knew that one would already be available in a few days(no need to reinvent the wheel). I have been thinking about this quite a bit.

Re: Where is the multi object tracking code for the RC?
 

My question, what is the best way to change those PWM outputs to a tangible angle for the tangent function to use? Our team didn't get to test the camera much last year... So it's all sort of new for me. Obviously it has to be in radians, because, correct me if I'm wrong the tan function in C is based off of radians.

I've thought about ways to do this, and it isn't all too complicated... I just need to test it out, and make sure 127 would be the camera pointing parallel with the ground. I'll get to testing it, but I'm wondering what you guys have come up with for this?

Re: Where is the multi object tracking code for the RC?
 

You might as well start experimenting. Neither Kevin, nor anyone else(apart from maybe GDC) knows how autonomous will turn up. If Kevin comes up with a better solution for your purpose, use it.

Re: Where is the multi object tracking code for the RC?
 

I believe the best way is not to use the tangent function on an angle in the code. It's both easier and quicker to use a small lookup table that turns the camera tilt PWM value into a distance.

You can use a tangent function when you create the lookup table, of course. Or you can fill in the table empirically by repeatedly placing the robot a known distance from the target and observing the tilt angle.

Re: Where is the multi object tracking code for the RC?
 

Ahh, that makes a lot of sense. Thanks.

Re: Where is the multi object tracking code for the RC?
 

Just FYI, you can create that table, and read from it using the EEPROM code at http://kevin.org/frc.

Edit: I also wrote some example code that creates an 8- and/or 16-bit sine table in EEPROM with one piece of code and then allows you to quickly do a sin() or cos() lookup using another piece of code (stuff written to EEPROM is permanent until you erase it). I haven't written any formal documentation yet, but I think the code is fairly readable. The code can be found here: http://kevin.org/frc/frc_trig.zip.

-Kevin