水下无人系统学报

Underwater Magnetically-Coupled Resonant Wireless Power Transfer Technology and Its Applications: A Review

WEN Hai-bing, SONG Bao-wei, ZHANG Ke-han, YAN Zheng-chao

2019, 27(4): 361-368. doi: 10.11993/j.issn.2096-3920.2019.04.001

[Abstract](627) [PDF 2147KB](583)

Abstract:
The magnetically-coupled resonant wireless power transfer(MCR-WPT) technology has the advantages, such as good insulation, simple structure, high power supply security, and convenient operation, compared with the conventional wet plug interface power supply technology, this technology has good prospects of application to underwater power supply for marine electromechanical equipment like undersea vehicle. This paper introduces the underwater MCR-WPT technology in terms of the basic structures and principles, with emphasis on its particularity in marine environment; discusses the research status and hot topics of MCR-WPT from the aspects of mechanism and application; and analyzes the technical problems to be urgently solved and the development trends, with respect to power transfer mechanism, design of electromagnetic coupler, system adaptability to marine environment, electromagnetic compatibility and new materials. The purpose of this paper is to provide a reference for development and application of underwater MCR-WPT in China.

Review of Research Hotspots of Superspeed Undersea Vehicle Control Methods

LIU Wei, FAN Hui, LÜ Jian-guo

2019, 27(4): 369-378. doi: 10.11993/j.issn.2096-3920.2019.04.002

[Abstract](653) [PDF 619KB](511)

Abstract:
With the help of supercavitation drag-reduction technology, the speed of the superspeed undersea vehicle could reach over 200 kn, and this is difficult for conventional fully wet vehicles. In recent years, the researches on this kind of vehicles have shown a leading trend from mechanism to application. Under this trend, control method of superspeed undersea vehicle has become a hotspot in this field. In this paper, the concept of the superspeed undersea vehicle is given, and the latest progress at home and abroad is reviewed. Then several hot research issues are put forward and analyzed, including the discussion about the widely quoted Dzielski model, and the dynamic characteristics such as nonlinear sliding force and system uncertainty, as well as the comparison among the popular control methods, such as linear control, feedback linearization, variable structure control, and fuzzy control. Finally, the latest researches are summarized, and future development directions are prospected. It is pointed out that expansion of the description range of controlled object will be the main driving force on future development of superspeed undersea vehicle control, and intelligent control will also become one of its important research directions.

Direction-of-Arrival Estimation Using Eigenvectors of Covariance Matrix of Circular Array

ZHU Shao-hao, YANG Yi-xin, WANG Yong

2019, 27(4): 379-385. doi: 10.11993/j.issn.2096-3920.2019.04.003

[Abstract](596) [PDF 652KB](402)

Abstract:
To solve the problem that the traditional high-resolution direction-of-arrival(DOA) estimation algorithms have a large amount of computation and are not robust, the eigenvectors of noise covariance matrix of a circular array in isotropic noise field are used to redefine the eigenvectors and array manifold vectors with different orders, and the data sampling covariance matrix is reduced in dimension according to the orders. Then, DOA estimation is performed using the minimum variance distortionless response(MVDR) with the new array manifold vectors and dimension-reduced data sampling covariance matrix. Simulation results show that if there is no error, the highest-order DOA estimation result is consistent with that of the traditional MVDR method. When amplitude and phase errors exist, the more robust low-order DOA estimation results are better than that of the traditional MVDR method, which indicates that the proposed method improves the anti-error robustness, and greatly reduces the amount of computation of matrix inversion. A 12-element uniform circular array is used in the experiment conducted in the sea trail, and the results of the 2nd- and 3rd-order DOA estimation are better than that of the traditional MVDR method, verifying the effectiveness of the proposed method. This DOA estimation method may contribute to applications of circular arrays to unmanned undersea systems.

Characteristics of Torpedo Power System Based on Multidimensional Co-Simulation Technology

LI Xin, YANG Cheng-shi, PENG Bo

2019, 27(4): 386-391. doi: 10.11993/j.issn.2096-3920.2019.04.004

[Abstract](496) [PDF 568KB](212)

Abstract:
To obtain the mutual influence law of the torpedo power system and components with characteristics change, a zero-dimensional performance simulation model of the power system, a one-dimensional simulation model of the engine’s in-cylinder process and a three-dimensional virtual prototype model of the engine are established. These relatively independent zero-dimensional, one-dimensional and three-dimensional simulation models in traditional research are combined to make the numerical calculation more efficient and accurate. Furthermore, the performance of the power system and the dynamic characteristics of the engine are numerically calculated, and the forces and motion of the main engine parts under start-up, speed-change, depth-change and sea trial of the power system, as well as the influence of the engine intake ratio on the performance of the power system, are simulated. Simulation results are basically consistent with the test data. This co-simulation technology may become a new method for design of torpedo power system and engine components.

Wideband Acoustic Imaging of Underwater Target Using Spatial Time-Frequency Analysis

DU Jin-xiang, XU Heng-bo

2019, 27(4): 392-397. doi: 10.11993/j.issn.2096-3920.2019.04.005

[Abstract](367) [PDF 521KB](273)

Abstract:
Wideband acoustic imaging for moving target needs a large amount of computation because the scan is conducted in both range dimension and time scale dimension. On the other aspect, the waveforms with Doppler tolerance for underwater target detection have low resolution in time scale dimension, which leads to poor speed estimation, as a result, the range error during the acoustic imaging cannot be eliminated effectively and the image will be distorted. To solve these two problems, positive and negative frequency modulation(FM) pulses strategy is utilized in acoustic imaging of underwater target, and the spatial time-frequency analysis, which combines beamforming in spatial domain with wideband cross-correlation in time-frequency domain, is used to analyze the echo signals. Better speed estimation can be achieved without need for scanning in time scale dimension, so the computational load is decreased and better range migration correction performance is obtained. The better performance of the positive and negative FM pulses strategy is verified by simulation results of moving target with multiple highlights.

Improved Detection Algorithm of Ship’s Shaft-Frequency Electric Field Based on Signal Features

LI Yue, ZHANG Jia-wei, CHENG Jin-fang

2019, 27(4): 398-405. doi: 10.11993/j.issn.2096-3920.2019.04.006

[Abstract](558) [PDF 731KB](413)

Abstract:
To improve the detection probability of a target and reduce the rates of false alarm and missed alarm at lower signal-to-noise ratio(SNR), the shaft-frequency electric field signals of different ships are analyzed based on the measured underwater shaft-frequency electric field data. According to the features of the shaft-frequency electric field signal and the environmental electric field noise signal in time domain and frequency domain, the current detection algorithm of ship’s shaft-frequency electric field based on signal features is improved in terms of line spectrum identification and detection criteria. And the Welch method is employed to replace the original power spectrum estimation method. Thus, the improved algorithm needs less amount of calculation and is more real-time. Analysis on the simulated signals under different conditions and the measured signals of different types of ships shows that the improved algorithm realizes target detection at lower SNR, and satisfies the need to increase the probability of detection and reduce the false alarm rate. This algorithm is more suitable for water weapons with high precision, such as mine.

Single Observer Passive Localization Algorithm Based on Iterated Measurement Updating Filter

XIONG Lu, SHEN Jian, BI Xiao-wen, CHEN An-quan

2019, 27(4): 406-412. doi: 10.11993/j.issn.2096-3920.2019.04.007

[Abstract](537) [PDF 496KB](212)

Abstract:
Single observer passive localization has strong concealment performance, and can avoid the problem of data fusion and synchronization among multiple observing platforms. To address the performance degeneration of single observer passive localization affected by the factors such as measurement error consistency and initial state error, a single observer passive localization algorithm based on iterated measurement updating filter(IMUF) is proposed in this paper. Firstly, based on the theory of linear estimation, the classical one-step discrete linear estimator update is rewritten as the step-by-step updating process in continuous time. Secondly, the evolution equations of continuous stepwise state and its error matrix are deduced and the iterated measurement updating equation is obtained by discretization. And then, the Sigma point method are used to approximate calculate the Gaussian matrix included in updating equations, and the IMUF is obtained, which has the Kalman filter-like computation form and is suitable for single observer passive localization. Finally, compared with the classical method, the experimental results show that the IMUF algorithm can effectively deal with the performance degradation problem under non-uniform measurement error and large initial state error, with better filtering convergence and estimation accuracy.

Simulation on Motion in Vertical Plane of a Latent Weapon Released Underwater

LIAN Yong-qing, SONG Bao-wei, LI Zong-ji

2019, 27(4): 413-419. doi: 10.11993/j.issn.2096-3920.2019.04.008

[Abstract](409) [PDF 503KB](260)

Abstract:
To study the motion law in vertical plane of a latent weapon released from submarine and the feasibility of using the separation and deceleration scheme to realize safe landing of the weapon, the motion process after release is divided into two stages: the first stage is from the latent weapon sinking until before separation, and the second stage is from separation beginning until weapon landing. Mathematical models are deduced respectively for these two different stages of motion. And the whole motion process of the weapon is simulated. The characteristics of the initial motion are analyzed, and the weapon landing law according to the separation and deceleration scheme is obtained. Simulation result shows that the separation and deceleration scheme is feasible for safe landing of latent weapon.

A Method for Fast Compensating Direct Coupling Interference of Wideband Electromagnetic Fuze

TAN Si-wei, ZHAO Jun, ZHANG Meng, REN Zhi-liang

2019, 27(4): 420-427. doi: 10.11993/j.issn.2096-3920.2019.04.009

[Abstract](588) [PDF 661KB](178)

Abstract:
Wideband signal has anti-interference and counter-countermeasure properties. However, engineering application of wideband signal to torpedo electromagnetic fuze still faces many problems, including fast and efficient compensation of wideband direct coupling interference. In this paper, the characteristics of direct coupling interference of torpedo wideband electromagnetic fuze are analyzed, and a fast and efficient compensating method for wideband direct coupling interference is proposed. The transfer function of Butterworth low filter is used to modify the iterative updating model of forgetting factor in recursive least squares algorithm. The modification resolves the contradiction between the ability of singular signal fast tracking and the low steady state error. This method is applied to adaptive compensation of direct coupling interference of torpedo electromagnetic fuze with two wideband signal systems of frequency hopping and phase modulation, respectively. Simulation analysis shows that the improved adaptive algorithm has better tracking performance of singular signals with low steady state error. The proposed method could realize fast and efficient compensation of the direct coupling interference in the wideband signal systems of frequency hopping and phase modulation, respectively.

Test Method of Hydrodynamics in Cavitator Control Process

ZHANG Ke, LI Peng, YAN Kai, CHEN Wei-zheng, WANG Zhi, WU Wen-ting

2019, 27(4): 428-433. doi: 10.11993/j.issn.2096-3920.2019.04.010

[Abstract](503) [PDF 1057KB](199)

Abstract:
Cavitator is one of the main devices for the attitude control of a supercavitation vehicle. By precise calculation and optimization, a water tunnel test model is designed and an unsteady measurement method of hydrodynamics in the water-tunnel is proposed for the cavitator control process. The control of the cavitator, as well as the measurement of pressure inside cavity and hydrodynamics, is realized in the condition of compact arrangement of the linear motor, displacement sensor, pressure sensor, transmission system, ventilation system and force balance inside the test model. The test method is verified by comparison between the results from test and empirical formula in static condition.

Design of a Multi-Target Interference Resistant Constant False Alarm Rate Detector for Homogeneous Reverberation Background

YIN Chao-ran, YAN Lin-jie, HAO Cheng-peng, SUN Meng-ru

2019, 27(4): 434-441. doi: 10.11993/j.issn.2096-3920.2019.04.011

[Abstract](301) [PDF 545KB](307)

Abstract:
To improve the ability of constant false alarm rate(CFAR) method against interference of multiple targets, a new CFAR detector is designed. The unbiased minimum-variance estimation(UMVE) method and the cell average(CA) method are applied to the data of left and right reference windows to obtain two local estimates, and then the smaller of(SO) two is taken as the power level estimate of homogeneous reverberation background. Under the assumption of Swerling II target, the closed-form formulas of the UMCASO-CFAR detector’s false alarm probability and detection probability in homogeneous reverberation background are derived, CFAR property of the detector is proved. Further, the performances of the detector in both homogeneous background and multi-target environment are discussed by means of analytical method, Monte Carlo simulation and measured data processing. The results show that compared with the existing methods, the UMCASO-CFAR detector has higher capability to resist mul-ti-target interference, and ensures a very small CFAR detection loss in homogeneous reverberation background.

An Outer Field Calibration Method of IMU Gyro Constant Drift

RUAN Wei, ZHANG Qin-nan, DI Yu-ru, GUO Lin-na, WANG Li-wen

2019, 27(4): 442-445. doi: 10.11993/j.issn.2096-3920.2019.04.012

[Abstract](328) [PDF 393KB](224)

Abstract:
To solve the problem of inertial measuring unit(IMU) gyro constant drift in outer field calibration, a three-position outer field calibration method of IMU gyro constant drift is proposed. Under the static pedestal condition, the attitude angles of the product are measured by the secondary alignment technique, and then the north gyro drift is estimated by Kalman filter. Finally, the gyro drift is solved by the least squares method via combining the attitude angles of the three positions with the north gyro drift. Simulation results show that this method can estimate gyro constant drift effectively without using turntable.

Shooting Method of Rocket-Assisted Torpedo Based on Target Board Judgment

ZHAO Ai-qi, WANG Ge, SUN Jian, GAO Tian, JIANG Li-wei

2019, 27(4): 446-451. doi: 10.11993/j.issn.2096-3920.2019.04.013

[Abstract](472) [PDF 510KB](244)

Abstract:
Based on the characteristics analysis of the anti-submarine operation and underwater trajectory of rocket-assisted torpedo, the conventional method for shooting target’s present position is improved and optimized. The judgment of the target board is used to determine the underwater search mode of the military load and offset aiming of the water-entry point. And then the shooting data of rocket-assisted torpedo is determined. Mathematical shooting models of single rocket-assisted torpedo and two rocket-assisted torpedoes salvo are established. Simulation analysis on the anti-submarine operational effectiveness is carried out by using this method, and the results show that this method can effectively improve the anti-submarine operational effectiveness of rocket-assisted torpedo, especially improve the effect of hitting long-range and high-speed maneuvering targets.

Design and Implementation of a Path Tracking System for Fully Actuated AUV

YAO Jin-yi, ZENG Qing-jun, ZHOU Qi-run, ZHU Zhi-yu, BAO Ling-hui

2019, 27(4): 452-458. doi: 10.11993/j.issn.2096-3920.2019.04.014

[Abstract](618) [PDF 2264KB](276)

Abstract:
Aiming at the application requirements for such as recovery, underwater search and rescue, and so on, a path tracking control system for fully actuated autonomous undersea vehicle(AUV) is proposed based on global positioning system(GPS), Doppler velocity log(DVL), optical fiber inertial navigation, depth gauge and waypoint tracking. The distributed system structure of AUV, the software design based on MOOS, the hardware design based on PC104 bus architecture are introduced according to the independently developed T-Sea I type AUV prototype. The principle of waypoint tracking and the navigation algorithm based on GPS, DVL, optical fiber inertial navigation and depth gauge are discussed, and then a proportion-integral-derivative(PID) path tracking controller is designed. Lake test of path tracking is carried out and the test curves are analyzed to verify the validity of the proposed method.

Simulation of Torpedo Air Trajectory Based on Dual-Euler Method

REN Bin, WEN Zhi-wen, YANG Zhi-dong

2019, 27(4): 459-462. doi: 10.11993/j.issn.2096-3920.2019.04.015

[Abstract](461) [PDF 407KB](291)

Abstract:
Due to its advantages of obtaining torpedo’s attitude angle and position intuitively, Euler angle representation has been extensively applied to solve the differential equation of torpedo’s six-DOF motion. However, for the torpedo air trajectory, this representation will produce singular points at the pitching angles of ± 90°, leading to the fact that the Euler equation cannot be solved. Therefore, this paper employs the dual-Euler method to avoid such singularity. Based on the dual-Euler method, a mathematical model of torpedo motion is established, and the torpedo air trajectory is numerically simulated. There is no divergence induced by the singularity during the calculation process. Simulations result shows that the torpedo air trajectory model based on the dual-Euler method can reflect the motion characteristics of torpedo air trajectory, and can achieve satisfactory performance at arbitrary angles. This work may provide a theoretical reference for the study of torpedo air trajectory.

A Safety Strategy Design Method of Autonomous Navigation for Long-Range Delivered Undersea Vehicle

LI Jie, MA Xu-kun

2019, 27(4): 463-468. doi: 10.11993/j.issn.2096-3920.2019.04.016

[Abstract](345) [PDF 456KB](209)

Abstract:
For delivering undersea vehicle in a long range, it is extremely necessary and urgent to research the safety strategy design method of autonomous navigation. The design methods in current researches cannot meet the requirements for autonomous navigation of long-range delivering undersea vehicle with small amount of testing data because they need more sensor information and have lower universality, and higher algorithms complexity. A route re-planning method based on the drawing method, as well as a mathematical model-based depth control design method, is proposed in this paper. On the premise of ensuring safety, the shortest path and steady depth control is taken as the criterion to analyze the depth control in the conditions of flat normal water depth(including deep water), shallow water, and sudden change of depth, and control flow is given. Simulation results verify that this method is simple and universal for safety strategy design of autonomous navigation for long-range delivered undersea vehicle, and it meets the navigation safety requirements for various circumstances.

Testing Scheme Design on Capability of Hovering Depth Charge Weapon System to Intercept Torpedo

HOU Bao-e, TIAN Heng-dou, LI Bing, FENG Peng-fei

2019, 27(4): 469-472. doi: 10.11993/j.issn.2096-3920.2019.04.017

[Abstract](467) [PDF 318KB](236)

Abstract:
For the assessment requirements of capability of hovering depth charge weapon system to intercept torpedo, a testing mode combining actual weapon launch with simulated launch is proposed. On the basis of the design idea of test route, specific testing methods are offered, including the method for determining the deployment area of assistant positioning buoy, the video recording scheme of depth charge water-entry point, and the testing data processing method, etc. Through testing, the assessment of the weapon system’s deployment capability and complete operation process is realized, and the capability of the weapon system to intercept torpedo can be evaluated objectively. Sea trial verifies the operability and practicability of the proposed design idea of test scheme, the video recording scheme for water entry point of depth charge, and the data processing method.

2019 Vol. 27, No. 4

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