Ultrasonic Source Localization
Algorithm

  • The transmitter and receivers operate at 40kHz. Hence, the Nyquist sampling rate is 80kHz.
  • Within each processing interval, the robot collects 0.5 s of data at a sample rate of 125kHz from each of the receivers.
  • The RMS voltages of the waveforms from both the channels are computed.
  • These RMS voltages are compared by computing the monopulse ratio.
  • The receiving sensor array is rotated by one degree in the direction of the sensor with the higher RMS voltage if the monopulse ratio is higher than 1.4. This is done by rotating the servo motor.
  • This process is repeated until the monopulse ratio is less than 1.4. This means the transmitter is aligned with the boresight axis.