Field of View Experiment

In order to test the capabilities of the the NXT ultrasonic sensor we conducted an experiment to demonstrate the width and length ranges at which the NXT sensor was still functional.

1. We layed our NXT robot, equipped with an ultrasonic sensor on the front of the robot, on a flat white board. The program detecting distance (cm) under 'view' was run.
2. After this, white masking tape was layed directly in front of the robot in a straight line for 2 meters.
3. Intervals of 10 cm were marked on the white tape
4. An object (Whiteboard eraser, flat side towards sensor) was slid down the white tape until the ultrasonic sensor no longer detected it. This position was marked with black tape.
5. At every 10 cm interval the whiteboard eraser was slid left and right until the sensor no longer detected an object. These positions were also marked with black tape.

Once the procedure was finished we marked down the black tape points on a smaller a4 paper which was divided into a grid. The distances were scaled down so as to fit onto the a4 grid, personally I used a scale of 2:1.

Now looking at the black tape pattern our group recognized that when an object was closer to the sensor, the sensors field of view was narrow (~5cm either direction). However past a certain distance, (~40-70cm) the sensors field of view widened to a maximum of about 20cm before gradually shrinking down in width to the maximum distance the sensor could read.
This formed a somewhat balloon-like shape.

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