dannyk
Did anyone successfully use the IR sensors this year? If so, how did you do it? If not, what did you learn?
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jgraber
Comments from a referee:
 There were several line-followers that worked.  We had one or two at DBEST, and I saw probably at least 4 at TX BEST.  I think Trenton had one.  I reviewed a notebook (Westbrook from USTEM) that also used the third sensor as a tower base sensor (front facing object detector) and the other two as a line follower.  Some were herky-jerky slow like mine, some had a very "nice" control.    
  Martin HS Notebook mentioned using them as wheel encoders, but they had too many glitches to use, so they put them back as line sensor position.   I talked to their programmer: even when working as wheel encoders,  if you just make both the right wheel and left wheel counts align by the end, you can still end up off track, due to an S-shaped path.  I suggested a physics based model, where you plot the robot position at each point along the path, based on the wheel base, wheel diameter, and encoder count for each wheel;  that method should track the S curve, and gives enough information to reverse the effects of S-curve. 

Wait, Martin HS your school dannyk.     Did you have other answers?
 
   Other comments from other schools I heard:  "IR sensors work, but only if going slow,  and it is faster and just as reliable to just do timed driving straight ahead."

Otherwise, try contacting Trenton and Westbrook.
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dannyk
Martin had a lot of theories as to why things did not work at Regionals. They had one unsuccessful auto at the Hub and one successful one at Regionals.
Right now they are just theories. Hopefully they will work on them.
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EvansPhysics

My kids used all three IR sensors for line following at the local competition. They worked, but delivery was so slow that by semifinals they edited the code to just drive straight for the tower without them (bump switch to end). That method was much more efficient, even if they missed the tower and had to restart.

For Regionals, they changed the sensor layout and their location on the robot. Delivery improved some, but it was still more efficient to just drive at the tower. We kept both options available in the code, but the drivers never once use line following during the competition.

We talked about editing the code to ignore a stray sesnsor error (one that oscilated too quickly) but never implemented it.  Maybe I'll task one of the coders to work on that in the off season.

I was watching one highlight video from a local competiton and the lines disappered from the courses halfway through the day. It turns out that no one at the competition (large enough to have 2 fields) was using line following and the tape was peeling and causing problems. They removed the tape and played on.

FYI, we 3D printed a housing for the 3 sensors that kept them separated to reduce interference and isolate reflections. We probably need to experiment with it to get more than just anecdotal results on its effectiveness.
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