Vessel-speed Enforcement System by Multi-camera Detection and Re-identification

2020 ◽  
Author(s):  
H. G. J. Groot ◽  
M. H. Zwemer ◽  
R. G. J. Wijnhoven ◽  
Y. Bondarev ◽  
P. H. N. de With
Keyword(s):  
Speed Enforcement ◽  
Vessel Speed

scholarly journals Multi-Camera Vessel-Speed Enforcement by Enhancing Detection and Re-Identification Techniques

Sensors ◽  
2021 ◽  
Vol 21 (14) ◽  
pp. 4659
Author(s):  
Matthijs H. Zwemer ◽  
Herman G. J. Groot ◽  
Rob Wijnhoven ◽  
Egor Bondarev ◽  
Peter H. N. de With
Keyword(s):  
Image Evaluation ◽  
Multiple Images ◽  
System A ◽  
Bounding Box ◽  
Camera View ◽  
Speed Enforcement ◽  
Identification Techniques ◽  
Application Specific ◽  
Time Selection ◽  
Vessel Speed

This paper presents a camera-based vessel-speed enforcement system based on two cameras. The proposed system detects and tracks vessels per camera view and employs a re-identification (re-ID) function for linking vessels between the two cameras based on multiple bounding-box images per vessel. Newly detected vessels in one camera (query) are compared to the gallery set of all vessels detected by the other camera. To train and evaluate the proposed detection and re-ID system, a new Vessel-reID dataset is introduced. This extensive dataset has captured a total of 2474 different vessels covered in multiple images, resulting in a total of 136,888 vessel bounding-box images. Multiple CNN detector architectures are evaluated in-depth. The SSD512 detector performs best with respect to its speed (85.0% Recall@95Precision at 20.1 frames per second). For the re-ID of vessels, a large portion of the total trajectory can be covered by the successful detections of the SSD model. The re-ID experiments start with a baseline single-image evaluation obtaining a score of 55.9% Rank-1 (49.7% mAP) for the existing TriNet network, while the available MGN model obtains 68.9% Rank-1 (62.6% mAP). The performance significantly increases with 5.6% Rank-1 (5.7% mAP) for MGN by applying matching with multiple images from a single vessel. When emphasizing more fine details by selecting only the largest bounding-box images, another 2.0% Rank-1 (1.4% mAP) is added. Application-specific optimizations such as travel-time selection and applying a cross-camera matching constraint further enhance the results, leading to a final 88.9% Rank-1 and 83.5% mAP performance.

Application of Computational Fluid Dynamics Simulations to the Analysis of Bank Effects in Restricted Waters

2009 ◽  
Vol 62 (3) ◽  
pp. 477-491 ◽  
Author(s):  
D. C. Lo ◽  
Dong-Taur Su ◽  
Jan-Ming Chen
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Cfd Modelling ◽  
Bank Effect ◽  
Force Increase ◽  
Computational Fluid Dynamics Simulations ◽  
Computational Fluid Dynamics Cfd ◽  
Dynamics Simulations ◽  
Yaw Angle ◽  
Vessel Speed

It is well known that vessels operating in the vicinity of a lateral bank experience a significant yaw moment and sway force. This bank effect has a major impact on the manoeuvring properties of the vessel and must therefore be properly understood to ensure the safe passage of the vessel through the restricted waterway. Accordingly, this study performs a series of simulations using commercial FLOW-3D® computational fluid dynamics (CFD) software and the KRISO 3600 TEU container ship model to examine the effects of the vessel speed and distance to bank on the magnitude and time-based variation of the yaw angle and sway force. The results show that for a given vessel speed, the yaw angle and sway force increase as the distance to bank reduces, while for a given distance between the ship and the bank, the yaw angle and sway force increase with an increasing vessel speed. In addition, it is shown that even when a vessel advances at a very low speed, it experiences a significant bank effect when operating in close vicinity to the bank. Overall, the results presented in this study confirm the feasibility of the CFD modelling approach as a means of obtaining detailed insights into the bank effect without the need for time-consuming and expensive ship trials.

scholarly journals The Simulation of Sloped Bank Effect Influence on Container Ship Trajectory

2021 ◽  
Vol 9 (11) ◽  
pp. 1283
Author(s):  
Mate Baric ◽  
Robert Mohovic ◽  
Djani Mohovic ◽  
Vinko Pavic
Keyword(s):  
Traffic Flow ◽  
Significant Influence ◽  
Suez Canal ◽  
Container Ship ◽  
Design Standards ◽  
Bank Effect ◽  
Flow Through ◽  
External Forces ◽  
The Impact ◽  
Vessel Speed

The latest container vessel grounding in the Suez Canal, which occurred on 23 March 2021 (the Ever Given), raised many questions regarding the safety of navigation. The sudden concern about safety is due to fears that traffic flow through the Suez Canal could be blocked for longer periods of time. Besides external forces imposed by wind, in this case bank effect had a significant influence on the ship’s grounding. Bank effect occurs due to restricted water flow caused by narrow waterways. Many fairway design standards consider sloped banks such as those of the Suez Canal as unsubstantial in bank-effect forces. This paper analyses the impact of sloped banks on container ship trajectory and proposes minimal distances that may decrease bank-effect forces in order to reduce the risk of vessel grounding and increase the safety of navigation. However, this type of accident has happened before and may occur again due to a small sailing distance from the bank in cases where vessel speed is increased.

Deterrent Effect of Fixed-Site Speed Enforcement on Freeways

CICTP 2016 ◽  
2016 ◽  
Author(s):  
Mengdie Yang ◽  
Jun Ma ◽  
Qiang Chen ◽  
Yichi Yang
Keyword(s):  
Deterrent Effect ◽  
Speed Enforcement
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