About the NXT Audio Sensor
The Lego NXT Audio Sensor, also known as the Sound Sensor, measures the sound pressure levels through the volume received in decibels (dB) and adjusted decibels (dBA). The measurement of dB detects all standard and unadjusted decibels, where all sounds are measured with equal sensitivity, which may include sounds that are too high or too low to be picked up by human ear. However, the dBA detects frequencies based on the human ear (frequencies around 3-6 kHz). Please note that the sensor should be placed as far away from the motor (wheels) as possible or else they will affect the noise that is picked up.
Botbot, powered by the NXT brick, is instructed to move based on the volume of the music being played, detected by the NXT audio/sound sensor. The power of the wheel motors that control Botbot's movement is determined by the amount of dB picked up through the sensor, which is influenced by the volume of Alex's voice.
||Video of Botbot's successful moves||
About our robot - "Botbot"
Our robot, Botbot, is a professional dancer. He moves based on the volume of the music, going faster when the music is loud and slower when it is softer. His amazing sense of volume has allowed him to become one of the best dancers in the robotic world!
As can be seen from the video, the speed at which Botbot moves is determined by the volume of Alex's beautiful voice.
Left: Building Process
Above: Control Program
Investigation
A Lego Mindstorm project that uses the audio sensor:
Industrial application of an audio sensor:
This robot created by "Hunter Chiou" demonstrates a practical use of a robot that can detect sound and move towards that source. The audio sensors allow the sound waves to be detected in which the robot is instructed to move towards that source.
Sound waves can be used to measure the temperature in harsh environment such as in nuclear power stations. Thermometers tend to lose accuracy in extreme environments and replacing or recalibrating would be a difficult task. The technology of using audio/sound sensors to detect sound waves uses the scientifically-proven fact of sound waves travelling faster in hotter mediums, and slower in colder mediums. This technology is used to accurately gauge the temperature in an industrial application. (To learn more, please click on the underlined title above the graph).
