For our experiment we decided to test the limitation and accuracy of the ultrasonic sensor. We started off by choosing three different objects to test our sensor on. We agreed on a small cereal bowl, a rubix cube, and a deodorant stick.
First of all, we moved the object around the sides of the sensors trying to detect the points at which the sensor started detecting the objects and the accuracy of the distance calculations. This way we were able to conclude that one side of the sensor has a wider range of detection. By trying this on all of the objects, we were able to take note of a few recurring measurements. By sliding our objects closer to the center of the sensor (not closer to the sensor itself but rather closer to its range) we were able to conclude that the previous numbers were off by a huge margin. For example, when one of the recurring measurements was 42.6 cm, when slid closer to the center the sensor would read closer to 19.3 cm, almost double of the first faint measurement. This helped us implement the conclusion that the sensor isn’t always accurate, but we were able to estimate the range of the sensor overall.
The second part of our experiment was more focused on the accuracy of the sensors measurements for objects placed directly in its line of vision. In order to test this, we remeasured the distance between the object and the sensor with a ruler. The sensors’ measurements were constantly off by -3 cm. This constant measurement led us to the conclusion that the received of the ultrasonic signals is not placed directly in front of the sensor but rather closer to the back of the sensor.
Overall, we learned that the ultrasonic sensor is very limited as to how accurate it can measure distances due to its range and uncertainty value of -3 cm. An ultrasonic sensor (other than Lego’s), however, can be used in real world autonomous robots to build a sense of position. Using ultrasonic sensors serves as another sense for these robots to detect distances, and objects within their range. An example of this in today’s world is autonomous cars. Ultrasonic sensors are essential for these cars to get by in the real world with a sense of what is surrounding them in order to reach the given destination in the safest and most convenient way possible.