Unmanned air vehicles often produce significant noise from their propulsion systems. Using this broadband signal as "acoustic illumination" for an auxiliary sensing system could make vehicles more robust at a minimal cost. We present an acoustic beamforming-based algorithm that estimates object-relative distance with a small two-microphone array using the generated propulsion system noise of a vehicle. We demonstrate this approach in several closed-loop distance feedback control tests with a mounted quad-rotor vehicle in a noisy environment and show accurate object-relative distance estimates more than 2x further than the baseline channel-based approach. We conclude that this approach is robust to several practical vehicle and noise situations and shows promise for use in more complex operating environments.

翻译：无人飞行器通常由其推进系统产生显著噪声。利用这一宽带信号作为辅助传感系统的"声学照明"，可以以极低成本提升飞行器的鲁棒性。我们提出了一种基于声学波束形成的算法，通过小型双麦克风阵列，利用飞行器推进系统产生的噪声来估计目标相对距离。我们在嘈杂环境中使用四旋翼飞行器进行了多次闭环距离反馈控制测试，证明了该方法能够比基线通道式方法更准确估计目标相对距离（距离超过基准方法的2倍）。实验表明，该方法对多种实际飞行器及噪声场景具有强鲁棒性，在更复杂的运行环境中展现出应用潜力。