scholarly journals The Acoustic System of the Fendouzhe HOV

Sensors ◽  
2021 ◽  
Vol 21 (22) ◽  
pp. 7478
Author(s):  
Yeyao Liu ◽  
Jingfeng Xue ◽  
Bo Yang ◽  
Min Zhu ◽  
Weizhen Guo ◽  
...  
Keyword(s):  
Electromagnetic Waves ◽  
Underwater Acoustic Communication ◽  
Integrated Navigation ◽  
Acoustic System ◽  
Long Distance ◽  
Radio Communications ◽  
Underwater Acoustic ◽  
Positioning Systems ◽  
Integrated Navigation System ◽  
Manned Submersible

Due to the strong absorption and attenuation of electromagnetic waves by water, radio communications and global positioning systems are lacking in the deep-sea environment. Therefore, underwater long-distance communications, positioning, detection and other functions depend on acoustic technology. In order to realize the above functions, the acoustic system of the Fendouzhe human occupied vehicle (HOV) is composed of eight kinds of sonars and sensors, which is one of the core systems of manned submersible. Based on the Jiaolong/Shenhai Yongshi HOVs, the acoustic system of the Fendouzhe HOV has been developed. Compared with the previous technology, there are many technical improvements and innovations: 10,000-m underwater acoustic communication, 10,000-m underwater acoustic positioning, multi-beam forward-looking imaging sonar, an integrated navigation system, etc. This study introduces the structure of the acoustic system of the Fendouzhe HOV and the technical improvements compared with the Jiaolong/Shenhai Yongshi HOVs. The results of the acoustic system are illustrated by the 10,000-m sea trails in the Mariana Trench from October to December 2020.

scholarly journals Airborne Integrated Navigation System Based on SINS/GPS/TAN/EOAN

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Junjun Tang ◽  
Peijuan Li
Keyword(s):  
High Precision ◽  
Navigation System ◽  
Integrated Navigation ◽  
Long Distance ◽  
Integrated Navigation System ◽  
Long Time ◽  
Federated Kalman Filter ◽  
Entropy Weighted ◽  
Navigation Errors ◽  
Navigation Information

Considering the drawbacks that GPS signal is susceptible to obstacles and TAN becomes useless in some area when without any terrain data or with a featureless terrain field, to realize long-distance and high-precision navigation, a navigation system based on SINS/GPS/TAN/EOAN is presented. When GPS signal is available, GPS is used to correct errors of SINS; when GPS is unavailable, a terrain selection method based on the entropy weighted gray relational decision-making method is use to distinguish terrain into matchable areas and unmatchable areas; then, for the matchable areas, TAN is used to correct errors of SINS, for the unmatchable areas, EOAN is used to correct errors of SINS. The principles of SINS, GPS, TAN, and EOAN are analyzed, the mathematic models of SINS/GPS, SINS/TAN, and SINS/EOAN are constructed, and finally the federated Kalman filter is used to fuse navigation information. Simulation results show that the trajectory of SINS/GPS/TAN/EOAN is close to the ideal one in both matchable area or unmatchable area and whose navigation errors are obviously reduced, which is important for the realization of long-time and high-precision positioning.

The Application of RAKE Receiving Technology in the Underwater SS Communication

2014 ◽  
Vol 513-517 ◽  
pp. 4248-4252 ◽  
Author(s):  
Yun Hang Zhu ◽  
Zhi Hui Deng
Keyword(s):  
High Speed ◽  
Simulation Analysis ◽  
High Reliability ◽  
Underwater Acoustic Communication ◽  
Technical Solution ◽  
Acoustic Transmission ◽  
Long Distance ◽  
Underwater Acoustic ◽  
Underwater Wireless Communication ◽  
Spreading Spectrum

In recent years, the strategic significance of the oceans is growing as well as its research and development needs. The underwater wireless communication is becoming more and more important. The underwater acoustic communication is one of the few mediums which can conduct the underwater transmission over a long distance, and the multipath effect is the major obstacle of affecting the systems high speed and high reliability. The characteristics of underwater acoustic fading and coherent multi-path channel are studied, and the model of underwater acoustic spreading spectrum (SS) communication system is established. The affect of coding technique on the systems performance are analyzed in detail. The improved RAKE receiving technical solution is put forward, whose simulation analysis and data in different combining ways are given. It is proved that the scheme can better solve the problem of multipath interference in underwater acoustic transmission.

scholarly journals An Ultra-Short Baseline Positioning Model Based on Rotating Array & Reusing Elements and Its Error Analysis

Sensors ◽  
2019 ◽  
Vol 19 (20) ◽  
pp. 4373 ◽  
Author(s):  
Jinwu Tong ◽  
Xiaosu Xu ◽  
Lanhua Hou ◽  
Yao Li ◽  
Jian Wang ◽  
...  
Keyword(s):  
Depth Information ◽  
Base Line ◽  
Positioning System ◽  
Positioning Error ◽  
Long Distance ◽  
Positioning Accuracy ◽  
Underwater Acoustic ◽  
Positioning Systems ◽  
Model Based ◽  
Underwater Positioning

The USBL (Ultra-Short Base Line) positioning system is widely used in underwater acoustic positioning systems due to its small size and ease of use. The traditional USBL positioning system is based on ‘slant range and azimuth’. The positioning error is an increasing function with the increase in distance and the positioning accuracy depends on the ranging accuracy of the underwater target. This method is not suitable for long-distance underwater positioning operations. This paper proposes a USBL positioning calculation model based on depth information for ‘rotating array and reusing elements’. This method does not need to measure the distance between the USBL acoustic array and target, so it can completely eliminate the influence of long-distance ranging errors in USBL positioning. The theoretical analysis and simulation experiments show that the new USBL positioning model based on ‘rotating array and reusing elements’ can completely eliminate the influence of the wavelength error and spacing error of underwater acoustic signals on the positioning accuracy of USBL. The positioning accuracy can be improved by approximately 90%, and the horizontal positioning error within a positioning distance of 1000 m is less than 1.2 m. The positioning method has high precision performance in the long distance, and provides a new idea for the engineering design of a USBL underwater positioning system.

Naval Energy Management System

2020 ◽  
Vol 26 (3) ◽  
pp. 20-25
Author(s):  
Laurențiu Bogdan Asalomia ◽  
Gheorghe Samoilescu
Keyword(s):  
Energy Consumption ◽  
Power Systems ◽  
New Technologies ◽  
Integrated Navigation ◽  
Integrated Navigation System ◽  
Efficient Management ◽  
Reduce Energy Consumption ◽  
Energy Efficiency Design Index ◽  
Green Ship

AbstractThe paper analyses the role of control and monitoring of electro-energetic equipment in order to reduce operational costs, increase profits and reduce carbon emissions. The role of SCADA and EcoStruxure Power systems is presented and analysed taking into account the energy consumption and its savings. The paper presents practical and modern solutions to reduce energy consumption by up to 53%, mass by up to 47% and increase the life of the equipment by adjusting the electrical parameters. The Integrated Navigation System has allowed an automatic control and an efficient management. For ships, the implementation of an energy efficiency design index and new technologies was required for the GREEN SHIP project.

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