FTC Training Robot Locomotion

Translating Counts to Distance

Straight

REV 41 1300 Core Hex Motor: 288 counts / rotation
REV 41 1354 90 mm dia Traction Wheel
pi d = 282.7 mm / rotation
282.7 mm / rotation / 288 counts / rotation = 0.9817 mm / count
Or about 1 mm / count

Tests

• 77 1/4 in
• 77 1/16
• 76 5/8
• Av 76.98 in
• 76.98 in / 2000 counts => 0.0385 in / count
• 0.9779 mm / count is within half a percent

Rotate

Distance between wheels = 8 ¼ inches = 209.55 mm
pi d = pi 209.55 mm = 658.32 mm / rotation
658.32 mm / rotation / 0.9817 mm / count = 670.6 counts / rotation

tests - degrees short of a full roation

• 17
• 16
• 32
• 42
• 35
• 17
• avg 27 degrees => 7 % error
• Inconsistent -> blame on OMNI wheels