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Unread 31-01-2009, 00:56
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TheOtherGuy TheOtherGuy is offline
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AKA: Kevin Forbes
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Re: 1726 progress - week 4

Thanks for all the feedback!

I sure hope the programmers get the robot for the last week this year, that would be a first! Although we're mostly still waiting for the rest of the robot to be "adjusted" before continuing

So we basically did a small distance test today with PWM values and distance; we managed to get very consistent shots considering the variety of conditions our balls are in. Plugged into a jaguar, here are the basic results:
Code:
output(0to1)   Distance
.3-.4          0-1ft
.4-.5          2ft
.5-.6          3-4ft
.6-.7          6-7ft
.7-.8          8-9ft
.8-.9          9-10ft
.9-1           9-10ft
Not very exact (off the top of my head, I'm pretty sure it's right) but it is much more accurate than it sounds. We'll map this out and create some relationship between the motor speed and distance. We're planning on using the height or size of the target as the distance calculator. If we have time we'll add some form of revolution counter to the shooter for more a more determinate angular speed than PWM values (3500rpm is kinda fast for an encoder... I saw 111 used a reflection sensor on their 2006 robot in the "Behind the Design" book? perhaps that'll work...).

EDIT: I have been reminded to mention that the distance calculated was between the front of the robot and the back of the trailer (space between the robot and target trailer). Which may or may not be important
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Last edited by TheOtherGuy : 31-01-2009 at 01:04.