Optimal coverage path planning for USV-assisted coastal bathymetric survey: Models, solutions, and lake trials

Abstract

With portable and cost-effective attributes, unmanned surface vehicles (USVs) are becoming a crucial role in coastal bathymetric surveys. However, in practical applications, the deployment of USVs for bathymetry encounters challenges from multiple facets, including intricacies of coastline shapes, determination of optimal coverage paths, and the sub-region sequencing. To address these issues, this paper introduces a novel coverage planning scheme designed for a coastal bathymetric survey in a lake region. The scheme commences with the Control Point Douglas-Peucker algorithm that effectively utilizes control points to envelope complex coastal lines, ensuring coastline accuracy while facilitating cellular decomposition. Subsequently, an optimal coverage strategy, characterized by fast convergence, complete coverage, and solution optimality, is meticulously designed to generate the most effective back-and-forth survey paths. Finally, by applying the mapping mechanism and fuzzy rules, a Fuzzy Biased Random Key Evolutionary Algorithm is devised to determine the optimal sequence of survey areas. Extensive simulation studies and comparative evaluations substantiate the superiority of the proposed scheme over existing state-of-the-art methods across various problem variants. In addition, real-world lake trials with USV SL-20 are conducted, providing empirical validation and emphasizing the augmented practicality of implementing the proposed methodology in engineering applications.