Transcript Ball Man

Ball Man – Sensor Oral
By Vivek Manoharan
TAs: William Dubel
and Steven Pickles
Bump Switch
• Basic use for an ENTER KEY
• Helps with initializing Ball Man under
different conditions
• LCD feedback initiates use of ENTER KEY
Photocell Resistor
• Indicates lighting conditions
• Helpful for differentiating between need for
white balance and not
Ultrasound Sensors – SRF-04
• Once one sensor is able to ping the tennis
ball, respective DC motor will “slow down”
to allow robot to turn
• Then, when ping rates are equal, DC
motors will run at same speed straight
ahead
• Experiments
Distance Accuracy
• Sample table, one
SRF-04
• Used maximum prescaling (1024)
• 148us = 1in
2
3.0900”
3.0”
3
5.1150”
5.0”
4
10.1928”
10.0”
5
15.3250”
15.0”
6
21.0547”
20.0”
Difference Tests
• Dual SRF-04 setup
• Measured offset
needed for BallMan to
understand “equal”
distances
5
0.375”
6
0.563”
7
0.438”
8
0.438”
9
0.563”
10
0.625”
CMU Camera
• Detect contrast level of tennis ball on
tennis court
• Green – Pickup tennis ball
• Bright Red – Home Base
• Test range of contrast detection
White Balance Indoors
• White Balance off
White Balance Indoors
• White balance on
Conclusion
• Further tests for CMU need to be run
outdoors
• White balance is crucial for contrasts
• Ultrasound ranges are not as far as
claimed (distances become iffy after 90”)