Ultrasonic Sensors
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Why do we use ultrasonic sensors?
Our research showed that ultrasonic sensors work in any weather condition, and they are available at a very low cost. Some ultrasonic sensors can accurately detect objects 50 feet away or more, and the experiments we conducted showed that:
For longer range detection of 150 feet away or more, our research showed that radar could possibly be used in place of the ultrasonic sensors. Even though radar units are more expensive and larger in size, we would like to be able to test a radar unit for our SuperVision device.
Why do we use ultrasonic sensors?
Our research showed that ultrasonic sensors work in any weather condition, and they are available at a very low cost. Some ultrasonic sensors can accurately detect objects 50 feet away or more, and the experiments we conducted showed that:
- Ultrasonic sensors can detect objects from a wide range of angles, protecting the user from all sides. (Four sensors can cover a 180 degree range behind the bicyclist.)
- Ultrasonic sensors are capable of detecting objects with reflective or non-reflective surfaces.
- Ultrasonic sensors remain accurate while in motion, such as on a moving bicycle.
For longer range detection of 150 feet away or more, our research showed that radar could possibly be used in place of the ultrasonic sensors. Even though radar units are more expensive and larger in size, we would like to be able to test a radar unit for our SuperVision device.
Click diagram to enlarge
This is a polar coordinates graph of the detection area covered by four LEGO NXT ultrasonic sensors mounted behind a robot. As you can see, four sensors cover a 180 degree range. Although the distance is on a smaller scale, a stronger ultrasonic sensor can detect objects 50 feet away or more.