Quote:
Originally Posted by Alan Anderson
You only need to check for the presence or absence of reflections from the horizontal target. A Class 1 laser sensor can be pointed at the dynamic vision target before the match begins, and it'll tell you whether or not the target is still there a moment after autonomous mode starts.
|
You hit the nail on the head Alan!
The
sensor I posted actually has a built in sensing light that illuminates when "the circuit is complete" for lack of a better term. This is all internal to the sensor. If the target is present both a green and amber light located on the top of the sensor will illuminate, if there is power to the sensor, but the target is not present, only the green light illuminates. That's the elegance behind a sensor of this design. Very easy to recognize the presence of the target without any additional coding or alignment mechanism. We weren't sure if this was the route we could take pre-Team Update 1... but after we learned that pre match setup will have both targets revealed, we went for it!
Like I said before, camera stuff consumes a lot of resources (at least on our team) e.g. coding time, debug time, and bandwidth among others, and we only use vision if we rule out all other possibilities. 5 extra points didn't seem worth consuming those resources to us, but in 1625 nature... we still wanted those points! haha So we opted for the laser. Team 2451 (formerly 2949) did a similar laser setup in 2012, from which we drew inspiration.
EDIT: In regards to
Quote:
Originally Posted by NotInControl
how do you know you are pointing ONLY at the horizontal target when placing on the field?
|
I guess it is a mixture of what I said above as well as both the retro-reflective properties of the tape and "trial and error" really... The retro reflectability of the tape will help us ensure there is no "spillage" of light from the vertical segment of tape, and "trial and error" helps improve our drive teams ability to position the sensor accurately. This "trial and error" methodology seems cumbersome yes, but most dead reckoned auton systems have some degree of this process.