An Experiment of Acoustic Navigation System Using Inverse Super Short Baseline for Underwater Vehicle

2014 ◽  
Author(s):  
Yoshitaka Watanabe ◽  
Hiroshi Ochi ◽  
Takuya Shimura
Keyword(s):  
Acoustic Signal ◽  
Relative Position ◽  
Navigation System ◽  
Deep Sea ◽  
Test System ◽  
Experimental Device ◽  
Doppler Velocity ◽  
Depth Information ◽  
Short Baseline ◽  
Mother Ship

Recently underwater vehicles are typically navigated with an inertial navigation system (INS), a Doppler velocity log (DVL), and an acoustic positioning system (APS). APS are necessary, especially in deep sea observation, because it is absolute positioning method. Super short baseline (SSBL) is frequently used because it is easy to operate. In SSBL, the position of vehicle is obtained on the mother ship. In order to use the positioning result to navigate the vehicle, the result is transmitted to the vehicle with a certain amount of delay. Authors are developing a test system of new type APS using inverse SSBL (ISSBL) method. In this method, the vehicle is equipped with a receiver array. Arrival direction of acoustic signal from mother ship is detected, and relative position between the mother ship and the vehicle is calculated with the obtained direction and the depth. Information of ship’s position is included in the transmitted acoustic signal, then absolute position of the vehicle can be calculated with the relative position and the included information. The vehicle position can be obtained in the vehicle in real-time and be used directly to navigate. No reply from the vehicle is necessary. An ocean experiment of this method was conducted in Sagami Bay in Japan. Experimental device was moored on the seabed and the ship cruised with acoustic signal transmission. As a result, this method was available in deep sea area. Demodulation of information in the method was feasible, and positioning of the experimental device was achieved. High rate positioning is useful suppress random error with filtering.

An Experimental Consideration on Accuracy of Inverse Super Short Baseline Underwater Positioning Using Acoustic Data Transmission

2016 ◽  
Author(s):  
Yoshitaka Watanabe
Keyword(s):  
Acoustic Signal ◽  
Relative Position ◽  
Estimation Error ◽  
Elevation Angle ◽  
Test System ◽  
The Other ◽  
Depth Information ◽  
Short Baseline ◽  
Other Hand ◽  
Mother Ship

Authors are developing a test system of new type acoustic positioning system (APS) using inverse super short baseline (ISSBL) method. In this method, the vehicle is equipped with hydrophone array. Direction of arrival (DOA) of acoustic signal from mother ship is detected, and relative position between the mother ship and the vehicle is calculated with the measured DOA and the depth. Information of ship’s position is included in the transmitted acoustic signal, then absolute position of the vehicle can be calculated with the relative position and the included information. The vehicle position can be obtained in the vehicle in real-time and be used directly to navigate. No reply from the vehicle is necessary. Five ocean experiments were conducted in various depth points. In the experiments, an experimental device was moored at sea bottom, and the ship cruised around above the moored device with transmitting acoustic signal including the ship’s information. In consideration about random scattering of positioning result, followings were found. Random scattering is much suppressed with EKF using high rate symbol value. On the other hand, estimation error of ship’s position, which is about 0.5–1 meter, is not negligible. When the DOA measurement for each symbol is accurate, the estimation error of the ship’s position becomes dominant in output of EKF as a consequence of random scattering suppression. Therefore, this method is more advantageous in case the DOA measurement have larger random error. Then this method is useful in deeper case and small array can be adopted to the system. On the other hand, this method do not perform well when the elevation angle from the target to the ship is shallow. Moreover convergence percentage seems to touch the lowest value at around 10%.

Conceptual Design of Navigation of an AUV for Monitoring CCS Site at Deep Sea Bottom

2011 ◽  
Author(s):  
Yoshitaka Watanabe ◽  
Hiroshi Yoshida ◽  
Hiroshi Ochi ◽  
Tadahiro Hyakudome ◽  
Shojiro Ishibashi ◽  
...  
Keyword(s):  
Conceptual Design ◽  
Navigation System ◽  
Autonomous Underwater Vehicle ◽  
Acoustic Method ◽  
Doppler Velocity ◽  
Depth Sensor ◽  
Short Baseline ◽  
Position Information ◽  
Sea Bottom ◽  
Acoustic Methods

We, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), are developing an autonomous underwater vehicle (AUV) whose main mission is monitoring a site at the sea bottom for the carbon dioxide capture and storage (CCS). The AUV cruises very near the sea bottom, and is equipped with chemical sensors in order to detect escape of CO2 from sub-bottom. Of course, the position information of the AUV is critical information for the monitoring. In this paper, a conceptual design of navigation of the AUV is described. Recently, navigation of AUV is implemented by integrating multiple navigation devices including inertial navigation system (INS), Doppler velocity log (DVL), depth sensor, acoustic navigation system, and others. The AUV under construction will be equipped with these navigation sensors, and will integrate those sensors’ outputs to navigate herself. In order to measure the absolute position of the AUV the acoustic method is one of fundamental technique. At the first step of development of the AUV, three acoustic methods are considered to adopt. The three methods are super short baseline (SSBL) method which is a tracking from support ship or other surface station, long baseline (LBL) which is navigation based on preplaced acoustic transponders, and virtual LBL (VLBL) which is navigation based on only single transponder. These acoustic methods are integrated with the navigation result of INS, depth sensor, and DVL. The three methods are used in each appropriate case. Which feature of observation is desired simplicity, accuracy, or independence from support ship and time efficiency? The acoustic method is influenced by environment, and also output of other sensors is depending on the environment, for example the DVL miss the data when the terrain is with many up-hills and down-hills. The integration or filtering parameters of the navigation should be adjusted depending on the influential environmental factor.

Analysis of Deep Sea Umbilical in Steep Wave Configuration

2016 ◽  
Author(s):  
Akash A. Nair ◽  
Gnanaraj A. Anbu ◽  
Panneer Selvam Rajamanickam ◽  
Gopakumar Kuttikrishnan ◽  
Ramadass Gidugu Ananda
Keyword(s):  
Deep Sea ◽  
Mining Machine ◽  
Optimum Number ◽  
Suitable Material ◽  
Static And Dynamic Analysis ◽  
Positive Displacement ◽  
Displacement Pump ◽  
Umbilical Cable ◽  
Steep Wave ◽  
Mother Ship

Deep sea mining is mineral retrieval process that takes place on the ocean floor wherein global industries are actively exploring and experimenting of different techniques in this relatively new concept of mining for extracting it economically from depths of 5000–5500 m below the ocean’s surface. National Institute of Ocean Technology (NIOT), India has been working on a mining concept for ∼6000 m water depth where a crawler based mining machine collects, crushes and pumps nodules to the mother ship using a positive displacement pump through a flexible riser (umbilical) system. The umbilical also serve as the weight supporting member for the miner and pump. In this paper, static and dynamic analysis of the umbilical system in steep wave configuration and the miner is carried out using ORCAFLEX for launching and touchdown conditions. Three different materials are considered and the best suitable material for umbilical is selected as the first step based on the tension. Then umbilical with Single Miner System is analyzed for the launching and touchdown conditions. Based on the analysis the optimum number and spacing of buoyancy tanks that will keep the stresses within the allowable limits in the umbilical cable are recommended.

scholarly journals A single acoustic beacon-based positioning method for underwater mobile recovery of an AUV

2018 ◽  
Vol 15 (5) ◽  
pp. 172988141880173 ◽  
Author(s):  
Ziye Zhou ◽  
Yanqing Jiang ◽  
Ye Li ◽  
Cao Jian ◽  
Yeyi Sun
Keyword(s):  
Autonomous Underwater Vehicle ◽  
Dead Reckoning ◽  
Underwater Vehicle ◽  
Doppler Velocity ◽  
Fusion Algorithm ◽  
Time Step ◽  
Short Baseline ◽  
Positioning Method ◽  
One Step ◽  
The One

This article presents a navigation method for an autonomous underwater vehicle being recovered by a human-occupied vehicle. The autonomous underwater vehicle is considered to carry underwater navigation sensors such as ultra-short baseline, Doppler velocity log, and inertial navigation system. Using these sensors’ information, a navigation module combining the ultra-short baseline positioning and inertial positioning is established. In this study, there is assumed to be no communication between the autonomous underwater vehicle and human-occupied vehicle; thus, to obtain the autonomous underwater vehicle position in the inertial coordinate, a conjecture method to obtain the human-occupied vehicle coordinates is proposed. To reduce the error accumulation of autonomous underwater vehicle navigation, a method called one-step dead reckoning positioning is proposed, and the one-step dead reckoning positioning is treated as a correction to combine with ultra-short baseline positioning by a data fusion algorithm. One-step dead reckoning positioning is a positioning method based on the previous time-step coordinates of the autonomous underwater vehicle.

scholarly journals A Fault-Tolerant Filtering Algorithm for SINS/DVL/MCP Integrated Navigation System

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Xiaosu Xu ◽  
Peijuan Li ◽  
Jian-juan Liu
Keyword(s):  
Kalman Filter ◽  
Navigation System ◽  
Fault Tolerant ◽  
Doppler Velocity ◽  
Observation Data ◽  
Integrated Navigation ◽  
Fusion Algorithm ◽  
Data Set ◽  
Integrated Navigation System ◽  
Short Period

The Kalman filter (KF), which recursively generates a relatively optimal estimate of underlying system state based upon a series of observed measurements, has been widely used in integrated navigation system. Due to its dependence on the accuracy of system model and reliability of observation data, the precision of KF will degrade or even diverge, when using inaccurate model or trustless data set. In this paper, a fault-tolerant adaptive Kalman filter (FTAKF) algorithm for the integrated navigation system composed of a strapdown inertial navigation system (SINS), a Doppler velocity log (DVL), and a magnetic compass (MCP) is proposed. The evolutionary artificial neural networks (EANN) are used in self-learning and training of the intelligent data fusion algorithm. The proposed algorithm can significantly outperform the traditional KF in providing estimation continuously with higher accuracy and smoothing the KF outputs when observation data are inaccurate or unavailable for a short period. The experiments of the prototype verify the effectiveness of the proposed method.

scholarly journals Improved Underwater Integrated Navigation System using Unscented Filtering Approach

2015 ◽  
Vol 69 (3) ◽  
pp. 561-581 ◽  
Author(s):  
Mohammad Shabani ◽  
Asghar Gholami
Keyword(s):  
Kalman Filter ◽  
Navigation System ◽  
Inertial Navigation System ◽  
Inertial Navigation ◽  
Doppler Velocity ◽  
Integrated Navigation ◽  
Integrated Navigation System ◽  
Measurement Models ◽  
Error State ◽  
Filtering Approach

In underwater navigation, the conventional Error State Kalman Filter (ESKF) is used for combining navigation data where due to first order linearization of the nonlinear equations of the dynamics and measurements, considerable error is induced in estimated error state and covariance matrices. This paper presents an underwater integrated inertial navigation system using the unscented filter as an improved nonlinear version of the Kalman filter family. The designed system consists of a strap-down inertial navigation system accompanying Doppler velocity log and depth meter. In the proposed approach, to use the nonlinear capabilities of the unscented filtering approach the integrated navigation system is implemented in a direct approach where the nonlinear total state dynamic and and measurement models are utilised without any linearization. To our knowledge, no results have been reported in the literature on the experimental evaluation of the unscented-based integrated navigation system for underwater vehicles. The performance of the designed system is studied using real measurements. The results of the lake test show that the proposed system estimates the vehicle's position more accurately compared with the conventional ESKF structure.

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