Download Final Report - Machine Intelligence Lab

IR Sensor 1
140
IR value
120
100
80
60
Series1
40
20
0
0
20
40
60
80
100
120
Distance (cm )
Figure 2
Ultrasonic Sensor
One ultrasonic sensor is used as simple radar for ranging. In one role, it is used in
obstacle avoidance for the front of the robot. In a second role, it is used as ranges for
detecting ping-pong balls. I found that using the ultrasonic sensor for detecting a ball is
very useful as it allows faster detection than the CMU camera. I took advantage of this
property and searched for objects using the ultrasonic sensor. After finding one, the
camera is used to decide whether it is an orange ball or not. The sensor had to be tested
for different positions. I finally placed it at the bottom close to the ground and pointing
slightly upward away from the ground. Another good place would have been at the top
looking slightly downward. I was able to detect a ball at maximum distance of about 1 m
when placed close to the ground. Figure 3 shows a graph of the returned values.
Ultrasonic Sensor
Ulrasonic value
20
15
10
5
0
0
20
40
60
80
100
120
Distance (cm )
Figure 3
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