A Novel Passive Localization Scheme of Underwater Non-Cooperative Targets Based on Weak-Control AUVs

Emerging autonomous underwater vehicles (AUVs) with small size, low speed, and low noise characteristics have shown promising applications in underwater monitoring. However, this also makes passive localization of underwater non-cooperative targets more challenging. Most localization schemes aim to improve localization accuracy while giving less consideration to additional related costs such as range flexibility, security, and energy consumption. To reduce such costs while ensuring accuracy, a weak-control AUV formation-based cooperative passive localization scheme is proposed, where AUVs do not require strict formation control or rely on anchor nodes to obtain absolute positions. Initially, there is a loose formation of multiple AUVs patrols until a target signal is passively and synchronously detected. Subsequently, the formation calibration is triggered. A rough formation calibration method is proposed based on signal interaction, where stratification effect compensation is considered. A precise formation calibration method adopting an inertial measurement unit and an extended Kalman filter algorithm is proposed to obtain a more accurate formation position by compensating for AUV drift error during rough calibration. Finally, the target position can be localized based on precise AUV formation using time difference of arrival method. Simulation and sea experimental results corroborate the efficiency and accuracy of the proposed localization scheme.