June 2024 OES Beacon

The Student Poster Competition at OCEANS 2024 Singapore

Dr. Yuen Min Too, Singapore LOC Student Poster Competition Chair
Dr.
Shyam Madhusudhana, IEEE—OES Student Poster Competition Chair

The OCEANS 2024 Singapore conference, held from April 14 to 18, 2024, featured a flagship event—the Student Poster Competition (SPC), which served as a platform for showcasing cutting-edge research by students in ocean engineering and marine technology. This year, the OCEANS Singapore SPC received 66 abstract submissions. Following a meticulous two-stage review process, 16 exceptional posters emerged as finalists for the competition. The selected candidates received comprehensive financial backing, encompassing coverage for their conference registration fees, as well as expenses for travel and accommodation, all thanks to the generous sponsorship of the Office of Naval Research Global (ONR-G). The Schmidt Ocean Institute has graciously continued its contribution of prize money for OCEANS Singapore SPC. We also extend our gratitude to our sponsoring societies, the Oceanic Engineering Society (OES) and the Marine Technology Society (MTS), for their unwavering support, without which the success of the SPC would not be possible.

At the conference, all finalists participated in the SPC, showcasing their work to a captivated audience during well-attended poster sessions. The students’ energy and enthusiasm were contagious, making the conference a truly enriching experience for all. We express our deepest appreciation to the esteemed panel of six judges who generously volunteered their time. The judges provided valuable feedback by interacting directly with the participants and scoring their posters. The OCEANS Singapore SPC culminated with a prestigious awards ceremony held during the conference’s Gala dinner. Local Organizing Committee’s SPC Chair, Yuen Min Too, and IEEE OES SPC Chair, Shyam Madhusudhana, presented participation certificates and winning prizes.

Below is the list of participants, including prize winners, along with their affiliations, poster titles, and abstracts:

 

Presenting certificates of participation to the finalists.
Awarding certificates of achievement to the winners.

First prize (Norman Miller Award) (Certificate and $ 3000)

Jonathan Lephuoc, Texas A&M University, USA

Design and Testing of an Amphibious Cycloidal Propeller Unmanned Underwater Vehicle

Abstract—This paper covers the design, development, and testing of a 43 kg (95 lb) amphibious cycloidal propeller unmanned underwater vehicle (Cyclo-UUV) that utilizes a combination of cycloidal propellers (or cyclo-propellers), screw propellers, and tank treads for operations on land and underwater. The use of cyclo-propellers allows for 360 thrust vectoring for more robust dynamic controllability compared to UUVs with conventional screw propellers. Four cyclo-propellers are used to control the Cyclo-UUV while underwater and can be retracted into a set of four wheels to allow for transitioning between underwater and land locomotion. Control of the vehicle underwater is achieved by modulating the cyclo-propeller rotational speed and blade pitch phase angle, allowing for control over the magnitude and direction of the thrust vector of each cyclopropeller to enable surge, heave, roll, pitch, and yaw motions. These changes to pitch phase angle are controlled by rotary servos which receive commands via an on-board autopilot with an inertial measurement unit (IMU) that measures the vehicle’s attitude and stabilizes the vehicle using a proportional-integralderivative (PID) controller. Systematic testing of the Cyclo-UUV was conducted to verify its mechanical operation, trim the cyclopropellers for forward motion, tune the PID controller gain values for good response and disturbance rejection, and evaluate the vehicle’s performance in both calm water and in the presence of breaking waves similar to those found in the surf zone. The Cyclo-UUV has demonstrated a high degree of maneuverability and controllability in forward motion underwater, as well as the unique capability of performing transitions between land and underwater through breaking waves.

Second prize (Certificate and $ 2000)

Sehwa Chun, The University of Tokyo, Japan

3D Detection and Tracking of Mooring Lines of Floating Offshore Wind Turbines by Autonomous Underwater Vehicle

Abstract—This paper introduces an innovative method for inspecting mooring lines of Floating Offshore Wind Turbines (FOWTs) using an Autonomous Underwater Vehicle (AUV) equipped with a tilt-controlled Multibeam Imaging Sonar (MBS). The approach aims to enable the AUV to accurately estimate the position of the mooring lines and safely track them. This method overcomes the limitations in traditional inspection techniques and lays the groundwork for the integration of additional methods for more detailed inspections.

With the tilt angle of the MBS and a pre-trained YOLO model, the AUV estimates 3D positions of the mooring chains with sonar imagery. The tracking method is designed to maintain safe distance to the chains by dynamically adjusting surge and sway velocities, based on the real-time detections. Through continuous tracking, the AUV is capable of reconstructing the whole structure of the mooring line with its position data estimated by dead-reckoning.

The proposed method was tested using a hovering type AUV, Tri-TON, in a sea trial at an FOWT, Hibiki, in Kitakyushu, Japan. The experiment validated the AUV’s effectiveness in tracking the mooring lines for 343 seconds and successfully reconstructing their entire structure. Moreover, the experimental results indicate a need for further tasks, particularly in enhancing the AUV’s positional accuracy and in conducting a thorough analysis of the chains’ physical characteristics to facilitate a more comprehensive evaluation of their condition.

Third prize (Certificate and $ 1000)

Shashank Swaminathan, Massachusetts Institute of Technology, USA

A Distributed “Any-Communication” Task Allocation Approach to Information-based Planning Underwater

Abstract—Autonomous ocean monitoring poses a unique challenge due to the dynamic and restrictive underwater environment. Distributed adaptive sampling can address many of the challenges of a large and evolving system; however, it typically requires strong assumptions on the communicability of the agents. This paper’s goal is to propose a novel “Any-Communication” approach to performing distributed adaptive sampling under limiting communication conditions, including the underwater space, through using a task allocation approach to information-based planning and a communication-robust distributed solver. The approach is verified against multiple randomized simulated trials, and the resultant improvement in optimality is compared against a naive distributed approach. The trials indicate that when under a simple linear cost agent model, the approach can provide up to 30% reduction in agent operational cost. More importantly, the improvement is proportional to the availability of communication. This works indicates the potential of the “Any-Communication” approach to distributed information-based planning under limited communication.

 Qianyi Zhang, Korea Advanced Institute of Science and Technology, South Korea

Feature-based Global Localization for Underwater Terrain Aided Navigation using Bag of Words

Abstract—This paper presents a novel feature-based global localization method for underwater terrain aided navigation (UTAN) using Bag of Words (BoW). Before the mission, the prior bathymetric map is segmented into submaps, and the handcrafted terrain gradient features are extracted from the submaps. Subsequently, a BoW is trained using these features, and the submaps are indexed accordingly. During the UTAN mission, place recognition is achieved by matching the index of the newly collected submap with the indexes of the submaps in the database, and the vehicle pose is determined using TEASER++ registration method. Experimental results using a sea trial dataset demonstrate that the proposed method can achieve a fast and robust global localization without requiring the prior initial vehicle pose information, offering robustness against substantial initial positioning and heading errors.

Thomas Chové, Thales/IMT Atlantique, France

Channel Model for Massive MIMO Underwater Acoustic Communications

Abstract—Oceans are an environment attracting growing interest, with major economic stakes. There exists a need to design systems able to explore the underwater environment, one of the challenges being the ability to communicate undersea. The underwater acoustic channel is considered as being one of the most difficult environments for designing communication systems, due to multiple limitations (frequency band, latency, Doppler effect…).

A method that could allow an increase of the data rate is the use of massive MIMO (multiple inputs, multiple outputs) systems, where many transducers are used to emit as well as to receive the signal. The objective of this paper is to present a model for a massive MIMO underwater acoustic communication channel in order to carry out a preliminary analysis of the impact of array correlation on the theoretical achievable rate by using Shannon capacity.

Xu Zhang, Shanghai Jiao Tong University, China

Design, Simulation, and Experiments of an Underwater Dredging Robot

Abstract—The paper studies underwater dredging robots for wall cleaning in long-distance water conveyance tunnels. Limnoperna fortunei and other organisms will adhere to water conveyance tunnel walls after a prolonged use, affecting the water’s quality. An underwater dredging robot was designed inside the tunnel walls to remove these organisms. The paper proposes a novel mechanical structure for underwater dredging. A detailed description of the machinery and control system of the working section is provided. Tests in actual pool experiments and simulations of nozzles demonstrated that the underwater dredging robot could effectively clean the adsorbed Limnoperna fortune.

Yipeng Meng, Hangzhou Dianzi University, China

Underwater Target Detection Based on Magnetic Gradient Tensor

Abstract—The Magnetic Anomaly Detection technique can be applied to locate and identify small-scale magnetic targets underwater. Compared to total magnetic field intensity and magnetic vectors, the magnetic gradient tensor has stronger anti-interference capabilities and provides higher-dimensional information. Utilizing pseudo-color imaging of the magnetic gradient tensor components combined with deep learning can reduce manual intervention and improve identification efficiency and accuracy. However, issues such as sparse measured data and poor magnetic imaging effects lead to poor identification accuracy. To address this, this paper adopts the Kriging interpolation method to increase magnetic gradient tensor data density and proposes an enhanced magnetic anomaly imaging method based on the boundary features of the target magnetic source. Additionally, Coordinate Attention is added to the neural network structure for improvements in identification accuracy. The analysis of finite element simulation data for common underwater magnetic targets demonstrates that the Kriging interpolation method results in smaller errors and higher accuracy compared to traditional linear interpolation methods. The enhanced magnetic anomaly imaging method ensures significantly clearer boundaries while maintaining the intensity of the target magnetic field. Furthermore, the addition of a coordinate attention to the detection model resulted in a 2% improvement in the mapping accuracy. In summary, this work provides a novel solution for the detection of small-scale underwater magnetic targets with different positions, intensities, and shapes.

Jingyu Qian, Zhejiang University, China

Cross-medium communication combining infrared optical and acoustic waves

Abstract—In recent years, direct communication across the water-air interface without relay has become possible by combining acoustic and millimetre waves. Present cross-medium communication schemes combining acoustic and electromagnetic waves are carried out in three steps. First, the underwater transducer sends acoustic waves, and the waves hit the water surface and induce vibrations. Then, a millimeter-wave radar in the air sends electromagnetic waves to detect the water surface vibrations. Last, after processing the received signals from the radar, cross-medium communication is achieved. However, this scheme suffers from short communication distances (approximately 1 m over water) and low resolution (millimetre level). Laser Doppler Vibrometry (LDV) is superior with high resolution and long measuring distances. Therefore, for the first time, we creatively adopted infrared LDV instead of millimeter-wave radar. This new approach improves the communication distance and distance resolution and achieves cross-medium communication with 10.8 m above water and 3.5 m underwater. In this article, we reveal the transmission mechanism of cross-medium communication combining infrared and acoustic waves and use experiments to preliminarily verify the feasibility of this scheme. In our experiments, we evaluate the effects of the depth and carrier frequency of the transmitted acoustic wave signals as well as the height of the receiving end on cross-medium communication.

Jeffrey Shao, University of New South Wales Sydney, Australia

Fractional Fourier Transform Based Channel Estimation in Underwater Acoustic Communications

Abstract—Underwater communications have severe channel distortions which can greatly affect its performance. This paper proposes a novel approach for estimating channel parameters (multipath delay and Doppler scaling) for underwater acoustic channels. The method is a Fractional Fourier Transform (FrFT) based approach with linear frequency-modulated (chirp) signals as a pilot. Innovation lies in the receiver design, where a 2D array is formed by performing a scan of FrFTs on the received signal. Key point detection algorithms are exploited to extract distinct X-shaped features in a 2D array, allowing for simultaneous estimation of both channel delay and Doppler parameters for all multipath components. The novel approach avoids the costly iterative process used in existing algorithms, which calculates Doppler scaling for one path per iteration. Simulation results show that the proposed algorithm is capable of estimating channel parameters in a severely time-delayed and Doppler-scaled multipath channel. The algorithm achieved a ±0.1% estimation accuracy with Doppler scaling factors ranging between 0.95 to 1.05. Multipath delay was estimated to within ±2ms for delays ranging from 0 to 0.2 seconds.

Xiao Feng, Northwestern Polytechnical University, China

Investigation of Three-Dimensional Sound Field Horizontal Refraction in Heterogeneous Topography

Abstract—The variability in seafloor topography is a primary factor influencing sound propagation. Complex and varied seabed topographies generate differing degrees of sound propagation effects, thereby altering the sound propagation loss compared to a flat seabed. This paper analyzes and statistically processes the slope data of the selected area’s terrain. It utilizes acoustic models to simulate and compare the sound propagation loss in convergence zones and near the deep-sea sound channel axis under different slope conditions. The findings indicate that an upslope terrain reduces propagation loss in convergence zones, and the propagation loss is minimized near the deep-sea sound channel axis when the downslope gradient is 7°. The paper also examines and discusses the impact of different bottom sediment parameters on sound propagation loss and the backscattering of acoustic energy in upslope conditions. Finally, the study analyzes the horizontal refraction effect in the three-dimensional sound field under complex terrain conditions from ray trajectories perspective.

Chia-Cheng Hsu, National Taiwan University, Taiwan

A Guidance Method for A Small Unmanned Surface Vehicle Wireless Charging

Abstract—A small unmanned surface vehicle (USV) usually carries a limited battery, and the mission duration is also limited. Wireless charging at sea is a way to extend the duration of USV. This work extends the study of developing a vector field-based guidance method for collision avoidance in the ship simulator. When the USV is in a vector field where near the charging station, the ship follows the vector field for guiding to touch the wireless charging plate. This vector field consists of a straight-line vector field and four circular vector fields in four quadrants to form a heading command to steer the ship. The feasibility of this work is tested by implementing the vector field guidance method into a ship simulator. In this work, the simulation considered wind, wave, and current influences on ship motions and combined the vector field-based guidance method to show the feasibility of the guidance method for USV wireless charging.

John Fischer, Naval Postgraduate School, USA

UPAD: A Large-Scale Passive Sonar Benchmark Dataset for Vessel Detection and Classification

Abstract—In the realm of underwater acoustics, the complex and dynamic environment poses formidable challenges for the detection and classification of vessels through passive sonar systems. Recent strides in deep learning (DL) have sparked optimism in automating or enhancing the data analysis process, traditionally reliant on human expertise. However, the efficacy of DL hinges on substantial training data, a resource currently scarce in the public domain, particularly for annotated real-world passive sonar data. This study endeavors to bridge this gap by presenting a methodology to construct a sizable annotated dataset by leveraging automatic identification system (AIS) data. The outcome of this effort is the Underwater Passive Acoustic Dataset (UPAD), an extensive benchmark dataset meticulously crafted for vessel detection and multi-label classification using passive sonar. UPAD not only addresses the dearth of publicly available benchmark data but also facilitates advancements in the application of DL for navigating the complexities of underwater acoustic environments.

Jinzhi Cai, Hong Kong University of Science and Technology, Hong Kong

Development of Desktop-Size Marine Swarm Research Platform

Abstract—Research in aquatic environments often demands extensive facilities, specialized knowledge, and dedicated support staff, which are expensive and usually out of reach for smaller research teams. Establishing accessible research infrastructure,

especially with testbeds and freely available software, can reduce entry barriers, shorten the time to implementation, and lessen the likelihood of failure in challenging underwater settings. To address these limitations in aquatic research, we have developed the Marine Automatic Swarm Experiment Platform (MASEP). MASEP is a tabletop-sized, marine swarm robotics testbed for evaluating underwater robotic swarm controllers, novel communication strategies, and more in a simulated aquatic environment. Through MASEP, we have successfully demonstrated the tracking and control of multiple robots, as well validated the robustness and reliability of an external visual localization system when fused with onboard sensor data. By enabling multi-robot tracking in a miniature, low-cost platform, MASEP opens up new possibilities for the advancement of underwater robot swarm testing and the development of effective control algorithms.

Jeremy Coffelt, University of Bremen/ROSEN Creation Center GmbH, Germany

Segmentation of Multibeam Echosounder Bathymetery and Backscatter

Abstract—Multibeam echosounders (MBES) are the tool of choice for high-precision underwater surveys, especially when water conditions render optical imagery ineffective. We present and evaluate the following approaches for MBES segmentation: (1) real-time processing of single sounding profiles using traditional machine learning techniques, (2) batch processing of “waterfall” pseudo-images using a standard U-Net model, (3) the same model adapted to 2D projections of 3D point clouds, and (4) post-mission, survey-level processing using modern networks specifically designed for sparse point clouds. Strengths and weaknesses of the methods are discussed, including data preprocessing requirements, robustness, and ease of implementation/interpretation. Evaluation is performed on real data collected by an autonomous underwater vehicle (AUV) during a deep-sea industrial pipeline inspection.

Fan Zhao, The University of Tokyo, Japan

Basic study of deep learning based efficient hermit crabs detection from drone-captured images

Abstract—The challenges arising from water clarity, depth, and other factors intensify the difficulties in surveying underwater hermit crabs, exacerbated by a notable shortage of practical field surveys. This study introduces a novel approach utilizing consumer-grade Unmanned Aerial Vehicles (UAVs) and deep learning to investigate underwater hermit crabs. We applied diverse super-resolution algorithms, employing distinct design strategies for image enhancement. Furthermore, we utilized the proposed object detection model developed from YOLOv8, achieving a mean average precision (mAP) of 0.722, surpassing other state-of-the-art object detection algorithms. Applying UAVs and super-resolution technology has significantly progressed underwater hermit crab detection, providing practical solutions for aquatic ecological monitoring, and enabling precise benthos detection.

Xin Qiao, Memorial University of Newfoundland, Canada

Global Significant Wave Height Retrieval From Spaceborne GNSS-R Using Transformers

Abstract—Global significant wave height (SWH) is a crucial element in ocean observation and spaceborne global navigation satellite system reflectometry (GNSS-R) stands as a novel remote sensing technique to achieve large-scale measurement. Delay Doppler Map (DDM) is a basic observable of GNSS-R and existing studies have demonstrated the effectiveness of convolutional neural networks (CNNs) in SWH retrieval from DDMs. However, CNNs are constrained by their limited receptive field, lacking the capability to establish long-range dependencies for the entire DDMs. To address this limitation, this paper proposes a novel model called WaveFormer which utilizes transformer architecture to extract features from DDMs. To evaluate the performance of the developed method, experiments are conducted on Cyclone GNSS (CYGNSS) data and results illustrate that WaveFormer achieves a lower root mean square deviation (RMSD) of 0.452 m than the CNN-based method.