Evaluating the Benefit of Using Multiple Low-Cost Forward-Looking Sonar Beams for Collision Avoidance in Small AUVs

TL;DR

This paper evaluates whether adding a few beams to a low-cost, small AUV's obstacle avoidance sonar improves performance, balancing complexity and cost against enhanced collision avoidance in cluttered environments.

Contribution

It provides a rigorous methodology to compare single-beam and multi-beam sonar systems, explicitly considering beam geometry and acoustic propagation for small AUVs.

Findings

Adding port and starboard beams improves obstacle detection.

Multi-beam systems offer better collision avoidance performance.

The methodology enables fair comparison of sonar configurations.

Abstract

We seek to rigorously evaluate the benefit of using a few beams rather than a single beam for a low-cost obstacle avoidance sonar for small AUVs. For a small low-cost AUV, the complexity, cost, and volume required for a multi-beam forward looking sonar are prohibitive. In contrast, a single-beam system is relatively easy to integrate into a small AUV, but does not provide the performance of a multi-beam solution. To better understand this trade-off, we seek to rigorously quantify the improvement with respect to obstacle avoidance performance of adding just a few beams to a single-beam forward looking sonar relative to the performance of the single-beam system. Our work fundamentally supports the goal of using small low-cost AUV systems in cluttered and unstructured environments. Specifically, we investigate the benefit of incorporating a port and starboard beam to a single-beam sonar system for collision avoidance. A methodology for collision avoidance is developed to obtain a fair comparison between a single-beam and multi-beam system, explicitly incorporating the geometry of the beam patterns from forward-looking sonars with large beam angles, and simulated using a high-fidelity representation of acoustic signal propagation.