Evaluation of an acoustic detection algorithm for reactive collision avoidance in underwater applications
This thesis sought to evaluate a vehicle detection algorithm based on a passive acoustic sensor, intended for autonomous collision avoidance in Unmanned Underwater Vehicles. By placing a hydrophone at a safe distance from a dock, it was possible to record the acoustic signature generated by a small motor boat as it navigated towards, and then away from the sensor. The time varying sound intensity was estimated by Root Mean Square of the sound amplitude in discrete samples. The time derivative of the sound intensity was then used to estimate the time to arrival, or collision, of the acoustic source. The algorithm was found to provide a good estimate of the time to collision, with a small standard deviation for the projected collision time, when the acoustic source was moving at approximately constant speed, providing validation of the model at the proof of concept level. Thesis Supervisor: Henrik Schmidt Title: Professor of Mechanical and Ocean Engineering