The University of Victoria’s Autonomous Underwater Vehicle (AUV) club AUVIC, competes in a yearly RoboSub competition. During this competition, the clubs’ AUV completes several tasks outlined by the RoboSub committee; such as collecting markers and using computer vision to decipher images. To navigate between these tasks the AUV needs to follow several acoustic beacons placed around the course.

A subsystem is needed to interpret the direction or location of these acoustic “pings” (momentary single frequency pressure wave emitted from the beacons) and communicate this information to the main “Trident” AUV. This data needs to be communicated within reasonable accuracy (< ~30⁰) and time (< ~2 seconds processing time); and must be accomplished within AUVIC’s budget.

This system will use one of the following solutions to calculate the expected location/direction of the beacons. The PCBA (Printed Circuit Board Assembly) will be designed to allow for either solution to be implemented.

Solution 1: Using a single hydrophone and an inertial measurement unit (IMU), a basic location can be calculated by observing the change in signal amplitude over time.

(SELECTED) Solution 2: Using a 4-hydrophone array it’s possible to calculate the position of an acoustic emitter based on the phase shift of the signal between each hydrophone or based on the signals’ time difference of arrival. This assumes the hydrophone locations are known and the speed of sound in water can be reasonably approximated.