Thread: Control testing
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Unread 17-11-2011, 11:44
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Mark McLeod Mark McLeod is offline
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FRC #0358 (Robotic Eagles)
Team Role: Engineer
 
Join Date: Mar 2003
Rookie Year: 2002
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Re: Control testing

The easy way to get distance per count is to:
  • Add a readout of the raw encoder value (essentially set distance per count = 1)
  • Layout a tape measure
  • Push your robot slowly 5 or 10 feet (or if it's an arm measure the rotation)
  • Divide count readout by inches pushed to get distance per count in inches.
  • Repeat to verify
You can calculate the value by knowing:
  • The number of counts per revolution of your specific encoder (all transistions for 4x)
  • gear reduction through transmission starting at the encoder mount point (not necessarily matched to the motor shaft rotation)
  • sprocket reduction between the output shaft and the wheel
  • The wheel circumference
  • Verify as before with a tape measure, readout, and pushing the robot a known distance
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Last edited by Mark McLeod : 17-11-2011 at 11:51.