Determination of Optimal Ship Route in Coastal Sea Considering Sea State and Under Keel Clearance

Lee, Wonhee; Yoo, Wonchul; GaeYoung, Choi; Ham, Seung-Ho; Kim, Tae‐Wan

doi:10.3744/snak.2019.56.6.480

Cited by 5 publications

(5 citation statements)

References 8 publications

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“…The navigation chart was provided by Korea Ocean Development Co., Ltd. (KORDO); sea depth data were provided by General Bathymetric Chart of the Ocean (GEBCO). To ensure vessel safety, the UKC to guarantee the minimum sea depth can be obtained using the following equation [55]:…”

Section: Data Used To Satisfy Safety Requirementsmentioning

confidence: 99%

Optimal Route Generation and Route-Following Control for Autonomous Vessel

Kim

Yang

2023

JMSE

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In this study, basic research was conducted regarding the era of autonomous vessels and artificial intelligence (deep learning, big data, etc.). When a vessel is navigating autonomously, it must determine the optimal route by itself and accurately follow the designated route using route-following control technology. First, the optimal route should be generated in a manner that ensures safety and reduces fuel consumption by the vessel. To satisfy safety requirements, sea depth, under-keel clearance, and navigation charts are used; algorithms capable of determining and shortening the distance of travel and removing unnecessary waypoints are used to satisfy the requirements for reducing fuel consumption. In this study, a reinforcement-learning algorithm-based machine learning technique was used to generate an optimal route while satisfying these two sets of requirements. Second, when an optimal route is generated, the vessel must have a route-following controller that can accurately follow the set route without deviation. To accurately follow the route, a velocity-type fuzzy proportional–integral–derivative (PID) controller was established. This controller can prevent deviation from the route because overshoot rarely occurs, compared with a proportional derivative (PD) controller. Additionally, because the change in rudder angle is smooth, energy loss by the vessel can be reduced. Here, a method for determining the presence of environmental disturbance using the characteristics of the Kalman filter innovation process and estimating environmental disturbance with a fuzzy disturbance estimator is presented, which allows the route to be accurately maintained even under conditions involving environmental disturbance. The proposed approach can automatically set the vessel’s optimal route and accurately follow the route without human intervention, which is useful and can contribute to maritime safety and efficiency improvement.

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Section: Data Used To Satisfy Safety Requirementsmentioning

confidence: 99%

Optimal Route Generation and Route-Following Control for Autonomous Vessel

Kim

Yang

2023

JMSE

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“…To create a route for a moving object, Ref. [ 6 ] considered the UKC (Under Keel Clearance) and generated the region with the risk of standing as grids. Ref.…”

Section: Introductionmentioning

confidence: 99%

Map Space Modeling Method Reflecting Safety Margin in Coastal Water Based on Electronic Chart for Path Planning

Jang

Kim

2023

Sensors

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Map space composition is the first step in ship route planning. In this study, a map modeling method for path planning is proposed. This method incorporates the safety margin based on the theory of geographic space existing in coastal waters, maneuvering space according to ship characteristics, and the psychological buffer space of a ship navigator. First, the obstacle area was segmented using the binary method—a segmentation method—based on the international standard electronic chart image. Next, the margin space was incorporated through the morphological algorithm for the obstacle area. Finally, to minimize the space lost during the route search, the boundary simplification of the obstacle area was performed through the concave hull method. The experimental results of the proposed method resulted in a map that minimized the area lost due to obstacles. In addition, it was found that the distance and path-finding time were reduced compared to the conventional convex hull method. The study shows that the map modeling method is feasible, and that it can be applied to path planning.

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“…The residual water level, which can have random and deterministic components, generally refers to the non-tidally forced water level variability. In abnormal weather conditions, the difference between the real water depth and the chart water depth can be several meters, which can easily lead to accidents such as grounding and stranding, especially for fishing boats and yachts ( Lee, 2021 ; Lee et al, 2019 ; Amdahl, Ehlers & Leira, 2013 ).…”

Section: Introductionmentioning

confidence: 99%

A method of constructing a dynamic chart depth model for coastal areas

Guan

Tian

Wang

et al. 2023

PeerJ

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The depth is important for vessel navigation at sea. Currently, most vessels use electronic navigation charts to navigate at sea. In coastal areas, especially close to shallow water areas, the dynamic change of the water level is very important to safe navigation. Ships calculate the change of water level by using up-to-date tide tables, to obtain the dynamic water depth in the channels. However, the depth caused by the tide and non-tidal components may reach several meters in some seas, causing the dynamic depth below the safety depth, which can easily lead to grounding of vessels stranding accidents. The channel is regularly dredged to achieve navigational depth. Without regular dredging, the offshore non-channel area becomes the common area of ship grounding. The dynamic chart depth model studied in this article can provide real-time depth, which serves the ships navigation in the non-channel. The model incorporates the chart depth and the dynamic water levels on the same reference datum. The chart depth is from the electronic navigational chart depth. The dynamic water levels are constructed by the simulated tidal levels and continuous series of nontidal residual. We then designed a deviation correction method to reduce the discrepancy of the simulated tidal level with the actual water level, including datum offset correction and residual water level correction. Finally, by merging the revised dynamic water levels with the electronic navigational chart depth, we obtained the dynamic chart depth model of the study region.

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Determination of Optimal Ship Route in Coastal Sea Considering Sea State and Under Keel Clearance

Cited by 5 publications

References 8 publications

Optimal Route Generation and Route-Following Control for Autonomous Vessel

Optimal Route Generation and Route-Following Control for Autonomous Vessel

Map Space Modeling Method Reflecting Safety Margin in Coastal Water Based on Electronic Chart for Path Planning

A method of constructing a dynamic chart depth model for coastal areas

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