水下无人系统学报

Complex Variable Boundary Element Method for Numerically Simulating Water Entry of a Wedge

WEI Zhao-yu, SHI Xiu-hua, WANG Sheng-wu

2011, 19(3): 161-166. doi: 10.11993/j.issn.1673-1948.2011.03.001

[Abstract](1585) [PDF 444KB](680)

Abstract:
To study the slamming problem of a wedge entering into water with constant speed, a complex variable boundary element method (CVBEM) based on the Cauchy integration equation is used in the numerical simulation, and the nonlinear free surface boundary conditions iteration with the shallow water approximation is also used to simulate the jet. The cubic spline interpolation is adopted to mesh the free surface. The size selections of the mesh and the control body as well as other relative numerical techniques are discussed. Consequently, the pressure distribution on wedge surface, the raise of free liquid surface and the jet pattern under different deadrise angle of sedge are achieved when it entering into water. The results show that when deadrise angle is small, the pressure on wedge surface is great, the jet is very thin and long without shake and burr, and the pressure distribution on jet approaches to zero, which indicates a perfect simulation of jet with the proposed method.

Signal Integrity Simulation of High Speed Serial RapidIO Bus Backboard

LI Yan, WU Pei-ming, KOU Xiao-ming

2011, 19(3): 167-171. doi: 10.11993/j.issn.1673-1948.2011.03.002

[Abstract](1309) [PDF 811KB](1141)

Abstract:
Signal integrity (SI) is a key problem in design of high speed bus. In this paper, the SI of high speed bus signal above 109Hz is analyzed, and ways to improve SI are put forward with respect to the influences of loss, crosstalk and reflection on SI. In the design of the high speed backboard, with the help of HyperLynx, a method for simulation and validation is proposed, in which LineSim is adopted to evaluate the main parameters affecting SI and achieve guiding data for design, and BoardSim is also adopted to validate the designed high speed backboard. The feasibility of the designed high speed serial rapidIO bus backboard is theoretically proved.

Trajectory Design and Simulation on Mine Attack Helicopter

ZHANG Ji-hua, ZHANG Yu-wen, FAN Hui

2011, 19(3): 172-175. doi: 10.11993/j.issn.1673-1948.2011.03.003

[Abstract](1721) [PDF 325KB](654)

Abstract:
A scheme for using a mine to attack a helicopter was proposed against mine-sweeping and mine-hunting by helicopters. The helicopter′s movement was analyzed. The change of force acting on the mine was analyzed during the process of water exit. Motion equations of the mine in water and air, and a mathematic model of the helicopter were established. The water exit attack trajectory of the mine was designed and simulated. Simulation results validate the feasibility of the trajectory design.

An FFT-Based Detection Method of Active Acoustic Fuse Echo for Anti-torpedo Torpedo

LI Yao-bo, SUN Chang-cun, REN Zhi-liang, WANG Tuo

2011, 19(3): 176-180. doi: 10.11993/j.issn.1673-1948.2011.03.004

[Abstract](1861) [PDF 304KB](798)

Abstract:
In order to detect acoustic fuse echo for anti-torpedo torpedo (ATT) in strong reverberation noise background, an echo signal detection method is put forward by using Doppler frequency feature on the basis of the characteristic differences between active acoustic fuse echo and reverberation of anti-torpedo torpedo. By using the proposed method, fewer receiving devices can search in the frequency scope from -50 kHz to 50 kHz. The operating characteristics of a receiver are simulated by Monte Carlo method. The results show that the echo signals can be detected by the FFT-based detection system of active acoustic fuse echo for ATT in strong reverberation noise background. And the detection probability is higher than 0.999 5 even if the false alarm probability is 10-4 when the SNR is higher than 3 dB.

Evaluation of Anti-interference Capability of Torpedo Electromagnetic Fuze Receiver Against Deceiving Jammings

ZHANG Tao, REN Zhi-liang, SUN Chang-cun, LI Yao-bo

2011, 19(3): 181-186. doi: 10.11993/j.issn.1673-1948.2011.03.005

[Abstract](1478) [PDF 301KB](700)

Abstract:
In order to analyze quantitatively and evaluate the anti-interference capability of a torpedo electromagnetic fuze receiver against deceiving jammings, an anti-interference coefficient and an amplitude coefficient are defined by analyzing the target characteristics and working principle of torpedo electromagnetic fuze, and the relational expression of the two coefficients is derived. Moreover, a quantitative evaluation method is put forward taking the anti-interference coefficient as an evaluation index. According to the typical filter circuit and timing test circuit in torpedo electromagnetic fuze receiver, their amplitude coefficients are calculated by using the circuit analysis method and their anti-interference coefficients are reckoned. The anti-interference capability of a torpedo electromagnetic fuze receiver against two deceiving jammings is evaluated with the anti-interference coefficient, and the result coincides with the measurement, which validates the feasibility and effectiveness of the proposed method.

Response Characteristic of Acoustic Homing Transducer to Intense Sound Pulse

QIAO Zi-liang, ZHANG Qun-fei, LEI Kai-zhuo

2011, 19(3): 187-191. doi: 10.11993/j.issn.1673-1948.2011.03.006

[Abstract](1255) [PDF 456KB](735)

Abstract:
To evaluate the effect of intense sound pulse on homing system, the response characteristic of acoustic transducer to intense sound pulse is investigated. An equivalent circuit model of typical transducer is established based on the admittance circle diagram method. With this model, the response characteristic is analyzed by computer simulations, and the results show that an oscillation appears in the equivalent circuit due to the intense sound pulse. Water tank experiment is conducted in underwater intense sound experiment system, and the intense sound pulse signal as well as the output signal of the transducer is collected. In the experiment, intense sound pulse also leads to an excited oscillation of the transducer, which validates the correctness of the equivalent circuit model. Furthermore, the correlation among responses of different transducers is poor, which disturbs bearing estimation process. The experimental results indicate that intense sound pulse imposes an apparent suppression effect on the homing system, and brings torpedo into a blinding status.

Performance Prediction of Active Detection Sonar under Reverberation

YU Yuan, YAN She-feng, HOU Chao-huan

2011, 19(3): 192-194. doi: 10.11993/j.issn.1673-1948.2011.03.007

[Abstract](1688) [PDF 288KB](1148)

Abstract:
According to active sonar equation, we predict the performance of active detection sonar under reverberation, discuss the influence of the frequency of active detection sonar on the detection range, and compare the detection ranges of the active sonar under different reverberation backscattering strength. The results show that the detection range of the active sonar decreases with decreasing frequency, and the performance of the active sonar enhances and the detection range extends with the weakening of reverberation backscattering strength. This study may be useful for selecting parameters of active detection sonar to enhance its performance in engineering.

Coordinated Path Tracking Control of Multi-UUV with Communication Constraint

MOU Chun-hui, BIAN Xin-qian, WANG Hong-jian, LI Juan

2011, 19(3): 195-200. doi: 10.11993/j.issn.1673-1948.2011.03.008

[Abstract](1461) [PDF 490KB](632)

Abstract:
Time delay exists in the underwater acoustic communication among UUVs. The purpose of this paper is to study multi-UUV coordinated control with time delay in communication for the path tracking of UUV formation. The path tracking controller of single UUV is designed based on backstepping method, and the path tracking control system is proved input-to-state stable by Lyapunov theory. Considering the fixed time delays in communication topology, a coordinated controller under time-delay based on uniformly connected in mean is proposed. It is proved that the designed formation control system is asymptotically stable if the undirected graph associated with the communication topology is uniformly connected in mean. The controller can effectively perform the coordinated path tracking control under time delay in communication for UUV formation. Simulation result shows its effectiveness.

Route Planning of Underwater Long-range Weapon Based on an Improved PSO Algorithm

CHU Lei, JI Jin-Yao, LUO Di

2011, 19(3): 201-204. doi: 10.11993/j.issn.1673-1948.2011.03.009

[Abstract](1243) [PDF 557KB](614)

Abstract:
An improved particle swarm optimization (PSO) algorithm with particle exchanging is proposed to solve the problem of moving back in the route planning of underwater long-range weapon based on basic PSO. Combining the route planning model of the underwater long-range weapon, this improved PSO algorithm is used in a combat simulation system of a certain long-range weapon. Simulation result shows that this algorithm can enhance the effect of the route planning and be helpful to the operational application of the long-range weapon.

A Cooperative Localization Method of UUV Based on Unscented Kalman Filter

LIU Ming-yong, SHEN Jun-yuan, ZHANG Jia-quan, HU Jun-wei

2011, 19(3): 205-208. doi: 10.11993/j.issn.1673-1948.2011.03.010

[Abstract](1762) [PDF 325KB](744)

Abstract:
The multi-unmanned underwater vehicles (multi-UUV) cooperative localization technology is important for solving the UUV localization problem in middle depth zone of the sea. To increase lower precision of multi-UUV cooperative localization using only range measurement, a cooperative localization method of UUV based on unscented Kalman filter (UKF) is presented in this paper. A follower UUV navigation model is derived from kinematic equation and measurement equation based on range of follower UUV. For the nonlinear navigation model, we designed navigation filtering algorithm using the UKF to avoid linearization of the nonlinear equations, and realized the recursive navigation filtering algorithm. Simulation results show that follower UUV can use the navigation filtering algorithm for real-time positioning. Compared with the traditional dead reckoning method, the new method has higher localization accuracy.

Vertical Plane Motion Control of UUV Near Free-surface Based on Active Disturbance Rejection Controller

SHI Xiao-cheng, CHEN Jiang, YAN Zhe-ping

2011, 19(3): 209-213. doi: 10.11993/j.issn.1673-1948.2011.03.011

[Abstract](2032) [PDF 377KB](760)

Abstract:
Unmanned underwater vehicle (UUV) is influenced by waves and noise, especially in the vertical direction, when it navigates near free-surface. In order to meet latency operation demand of UUV near the free-surface, we discuss a motion control technology based on active disturbance rejection controller (ADRC). This technology has stronger anti-interference capability, can combine the internal and external disturbances into the general disturbance of the system, and gives real-time estimates for the corresponding disturbance compensation. To solve the control disturbance problems of vertical plane motion for UUV near free-surface in ocean environment, we design a vertical plane motion controller of UUV by using this technology, and analyze its anti-disturbance performance. Simulation results show that the designed controller can effectively restrain the interference of waves and reduce the buffeting phenomenon of stern elevator, and has good control effect and anti-disturbance performance.

Modal Analysis of Gas Turbine Impeller for Underwater Vehicle

ZHAO Jun, SHAN Xiao-liang, FAN Xiao-bo

2011, 19(3): 214-217. doi: 10.11993/j.issn.1673-1948.2011.03.012

[Abstract](1473) [PDF 670KB](713)

Abstract:
To avoid resonance while gas turbine of underwater vehicle is working, a finite element model of gas turbine impeller is established under reasonable hypothesis. Modal analysis of the impeller is performed with the cyclic symmetry method of ANSYS, 12-order modes are discussed, and the influences of rotation speed and temperature on the modal of impeller are analyzed. The conclusions are in accordance with actual characteristics in engineering, which may contribute to the safe use, structure design and dynamics analysis of the gas turbine for underwater vehicle.

An Improved Speed Governing Circuit for Brushless DC Motor

CUI Jian

2011, 19(3): 218-220. doi: 10.11993/j.issn.1673-1948.2011.03.013

[Abstract](1046) [PDF 260KB](730)

Abstract:
To enhance the reliability of motor, a new pulse width modulation (PWM) circuit for speed governing is designed via analyzing the speed governing principle of brushless DC motor (BLDCM) and improving the PWM circuit for traditional speed governing system of brush DC motor. This new circuit makes use of single supply to overcome the influence of asymmetric dual supply on speed governing pulse width. The experimental results show that the new circuit is of less parts, better controllability, higher precision, and stable output with loose supply voltage requirement. The improved speed governing circuit can be extensively applied to measurement, communication, power control and conversion, etc.

Conductive Interference Analysis and Suppression for Torpedo Motor Inverter System

HU Ping, SUN Jiong, LIU Kai, SHAO Song-shi

2011, 19(3): 221-225. doi: 10.11993/j.issn.1673-1948.2011.03.014

[Abstract](1120) [PDF 429KB](722)

Abstract:
To solve the electromagnetic interference (EMI) problems of torpedo motor inverter produced by high power and high frequency, a new type of parallel resonant DC link inverter(PRDCLI) topology and control strategy are introduced, the principle is expounded. The EMI source and it′s propagation are discussed. Furthermore, a control strategy to reduce the EMI is presented, the EMI test scheme is designed, and the EMI spectrums under hard-switch and soft-switch are compared. Experimental results show that the adopting soft-switch technology and optimized control strategy can effectively reduce the EMI of torpedo motor inverter.

Maintainability Prediction Method Based on Analytic Hierarchy Process

SONG Bao-wei, DONG Bo-chao, LIANG Qing-wei, JIANG Jun

2011, 19(3): 226-230. doi: 10.11993/j.issn.1673-1948.2011.03.015

[Abstract](1188) [PDF 324KB](636)

Abstract:
Through analyzing the existing methods of maintainability prediction and considering the requirement of weaponry maintainability, a unit-contrastive prediction method based on analytic hierarchy process (AHP) is presented. This method can meet the qualitative and quantitative requirements of weaponry without asking huge number of historical data and test data samples. With this method, the maintenance data of weaponry can be achieved by analyzing the profile of maintenance tasks of weaponry to determine reference unit and its maintenance data, and comparing the other units with the reference unit. This method is simple, applicable and cost-saving, especially is convenient for maintainability design. Application of this method to actual torpedo launch tube verifies its effectiveness and feasibility.

Modeling and Simulation of Cooperative Defense Against Acoustic Homing Torpedo with Hovering Acoustic Decoy and Hovering Depth Charge Array

JIA Yue, YAO Feng-liang, DING Bei

2011, 19(3): 231-235. doi: 10.11993/j.issn.1673-1948.2011.03.016

[Abstract](1787) [PDF 348KB](958)

Abstract:
Properly deploying hovering acoustic decoy and hovering depth charge array to counter acoustic homing torpedo is of great importance for a surface ship. This paper establishes an operational model of ship countering torpedo with hovering acoustic decoy and hovering depth charge array, defines the launch strategy of hovering acoustic decoy and hovering depth charge array and the evading course of surface ship by using extremum method and the non-linear planning method, and effectively combines the deploying of decoy and depth charge array with the evasive maneuver to achieve the best countering effect. Simulation results show that the proposed method can effectively counter coming torpedo by combining the soft-kill and hard-kill anti-torpedo measures, and enhance the probability of intercepting torpedo by 10% ~30%.

Simulation and Experiment of an Inlet Control Valve for Air Powered Engine

LIAN Yong-qing, TIAN Bing, CHEN Yi-hui

2011, 19(3): 236-240. doi: 10.11993/j.issn.1673-1948.2011.03.018

[Abstract](1175) [PDF 717KB](1085)

Abstract:
To satisfy different flow rate demand of air powered engine, a new kind of inlet control valve is designed for the engine with variable flow based on the original mechanical launching valve. An experimental system of the inlet control valve is designed, a mathematical model of the experimental system is established, and simulation is performed. Consequently, the experimental system is set up, and the inlet control valve is tested. The simulation and experimental results indicate the rationality and validity of the design and the theoretical analysis of the inlet control valve. This experimental system may be used in joint simulation and experiment of the air powered engine.

2011 Vol. 19, No. 3

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