Biomimetic Sonars Videos

  • Rodolph – robot dolphin. Biomimetic sonar has a center transmitter flanked by two receivers. Side view. Front view.

    1. Using 60 kHz wide-bandwidth transducers and time-of-flight information at the two ears, Rodolph detects the O-ring. The sonar moves to position the O-ring at a predetermined location (15 cm along the transmitter axis). The O-ring then generates a unique pair of echoes (see next video), which are used to recognize the O-ring.
    2. ( Echoes from the O-ring observed at left and right ears. )(382KB)
      The echoes detected from a 16 mm diameter O-ring are shown, with the left ear shown on the top and the right ear on the bottom. The traces start just before a time-of-flight threshold is exceeded. The sequence of echoes is shown, starting with the first detected echoes, and ending with the echoes observed when the O-ring is positioned at the predetermined location. The echoes are then processed to extract the envelope, shown in yellow, over the extent of the waveform exceeding a perceptual threshold. The envelope is sampled every 8 microseconds (twice the period of the 60 KHz waveform) and the samples are stored in a database, with the left and right ears being separate entries.
    3. Echoes from a steel machine washer observed at left and right ears. (334KB)
      The echoes detected from a 19 mm outside diameter (8 mm diameter hole), 2 mm thick steel machine washer are shown. They are processed by Rodolph in the same manner as described above.
  • Obstacle Avoidance Sonar
    1. Eight strategically-placed Polaroid sonars on an Electric Mobility electric scooter and controlled by a PIC16877 micro-controller interface the joystick and the wheelchair controller. Obstacles are detected, speed is reduced, and joystick commands are over-ridden to avoid collision. Blindfolded user (Alex Kuc) navigates a crowded hallway.
    2. Qualitative sonar – tracking with no calculations performed.
  • Biomimetic sonar.

    1. This sonar has a center transmitter that has 25kHz and 40kHz piezoelectric transmitters. The pinna are paraboloids constructed with 3D printers. Each paraboloidal section focusses sound onto 25kHz and 40kHz receivers that have narrow bandwidths. Servo motors provide independent bearing and elevation motion for each pinna. The complete sonar head has five degrees of motion (x,y,z,bearing, elevation).
  • Tracking sonars.
    1. Qualitative sonar – tracking with no calculations performed. (511KB)
      This sonar has a center transmitter flanked by four receivers, a horizontal pair and a vertical pair. All transducers are 40 kHz narrow bandwidth PZT bimorphs. Simple logic determines which receiver in a pair detects the echo first and activates an air jet to push the sonar axis toward the object. Since no calculations are performed, this is our qualitative sonar. Interrogation pulses are emitted every 10 ms. This sonar operates correctly in the union of the beam patterns (since either ear detecting an echo causes activation), unlike triangulation, which operates over the intersection of beam patterns (since both ears must detect the echo).
    2. Robat – our Robot Bat sonar has a center transmitter flanked by two ears and performs triangulation.

      • This sonar has a center transmitter flanked by two receivers, which can rotate like bat pinnae. Interrogation pulses are emitted every 10 ms. Time-of-flight is determined at each ear and triagulation is performed to find the range and azimuth to the object. Since the transducer spacing is known, the angle by which the ear must be rotated to place the object on its axis can be determined.

      • Echo waveforms detected at the left (top) and right (bottom) ears. The horizontal line indicates the threshold, which is used to determine time-of-flight. The sonar moves to equalize the time-of-flight at both ears.