2015 Vol. 41, No. 1

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Volume 41 Issue12015
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Parameter optimization of pulse compression method in air-coupled ultrasonic testing
ZHOU Zhenggan, MA Baoquan, SUN Zhiming, ZHOU Hui, HUANG Ziyu, LIU Jingjing
2015, 41(1): 1-7. doi: 10.13700/j.bh.1001-5965.2014.0037
Abstract:
A variety of pulse compression methods are viewed as viable solutions to improve the signal to noise ratio (SNR) of received signal in air-coupled ultrasonic testing. However, the use of corresponding method to realistic inspection is faced with problem of optimal parameter selection to get better c...
Design of high-gain unknown input observer based on Riccati equation
ZHU Fanglai, ZHANG Yongjun
2015, 41(1): 8-13. doi: 10.13700/j.bh.1001-5965.2014.0041
Abstract:
For a class of Lipschitz nonlinear system, the reconstruction problems of state estimation, unknown input and measurement noise were studied. Regarding the measurement noise as an extended state, the original system can be transformed into a descriptor system. For the descriptor system, first, a hig...
Method for airborne video capture and preprocessing based on FPGA
JIANG Hongxu, LI Huiyong, LIU Tingshan, DUAN Miyi, ZHANG Ping
2015, 41(1): 14-22. doi: 10.13700/j.bh.1001-5965.2014.0467
Abstract:
Video capture, color space conversion and video data transmission were researched in order to improve video capture and pre-processing performance of airborne multi-mode video coding system. Taking into account the requirements of real-time multi-mode video capture, a robust video capture strategy b...
Wind turbine airfoil design method with low noise and experimental analysis
WANG Quan, CHEN Jin, CHENG Jiangtao, WANG Jun, SUN Jinfeng, YOU Ying
2015, 41(1): 23-28. doi: 10.13700/j.bh.1001-5965.2014.0072
Abstract:
In order to study the noise characteristic of wind turbine airfoils, the airfoil optimal design mathematic model was built based on airfoil functional integrated theory and noise calculated model. The new optimized objective function of maximizing lift/drag to noise was developed on the design angle...
Storage life assessment for solid propellant based on generalized linear model
HONG Dongpao, WANG Yinghua, GUAN Fei, MA Xiaobing
2015, 41(1): 29-32. doi: 10.13700/j.bh.1001-5965.2014.0030
Abstract:
To describe the influence of performance degradation on storage life and reliability for solid propellant, a method of storage life and reliability assessment based on generalized linear model was proposed. According to the characteristic of solid propellant degradation data, the local scale model w...
Evaluation method for distortion of arbitrary waveform
SUN Jingyu, WANG Zhongyu, LIANG Zhiguo
2015, 41(1): 33-37. doi: 10.13700/j.bh.1001-5965.2014.0079
Abstract:
The index of distortion to evaluate the total quality of waveforms has special advantages and has been accepted widely by most people. Based on the analyses of the distortion definition of arbitrary waveform, a method using nonlinear-curve-fitting to evaluate the distortion of arbitrary waveform was...
Experimental investigation on operational performance of loop heat pipe subjected to acceleration force
XIE Yongqi, YU Yin, XIE Liyao, GAO Hongxia, YU Jianzu
2015, 41(1): 38-44. doi: 10.13700/j.bh.1001-5965.2014.0049
Abstract:
To solve the problem of temperature oscillation, even operation failure when loop heat pipe with single compensation chamber was subjected to acceleration force, the experimental setup was built for testing the performance of dual compensation champers loop heat pipe (DCCLHP) based on the centrifuga...
V-estimator with corrective term for K-distribution shape parameter
LI Dapeng
2015, 41(1): 45-49. doi: 10.13700/j.bh.1001-5965.2014.0054
Abstract:
The V-estimator (VE) for K-distribution shape parameter proposed by Oliver in 1993, bears the characteristics of without solving non-linear equations so it has a high estimating efficiency, but the estimating accuracy of it is lower than that of many other moment estimators, sometimes the VE even re...
Nonlinear dynamic behaviors of electro-hydraulic servo system under friction
ZHU Yong, JIANG Wanlu, ZHENG Zhi
2015, 41(1): 50-57. doi: 10.13700/j.bh.1001-5965.2013.0685
Abstract:
With electro-hydraulic servo system as the research object, the influence laws of nonlinear friction on system dynamic characteristics were explored. Based on the principle of the nonlinear dynamics, the nonlinear dynamical model of system was established. Then, a conclusion was put forward that the...
Dynamic modeling for a morphing aircraft and dynamic characteristics analysis
ZHANG Jie, WU Sentang
2015, 41(1): 58-64. doi: 10.13700/j.bh.1001-5965.2014.0048
Abstract:
The physical model of a variable-span variable-sweep morphing aircraft was simplified. Based on Kane's method, the morphing movements were assumed to be controllable known input, and the wings' movements were expressed by constraint equations. The six components of the translational velocity and the...
Fast Bayesian DOA estimator using continuous ant colony optimization
JIAO Yameng, HUANG Jianguo, HAN Jing
2015, 41(1): 65-70. doi: 10.13700/j.bh.1001-5965.2014.0051
Abstract:
For the effectiveness of the ant colony optimization algorithm for solving high-dimensional nonlinear search problem, a Bayesian maximum posteriori direction of arrival (DOA) estimation fast algorithm based on the ant colony optimization algorithm (ACO-Bayesian) was proposed. This algorithm adopts B...
Method to estimate the Doppler parameters of moon-borne SAR using JPL ephemeris
DING Yixing, GUO Huadong, LIU Guang
2015, 41(1): 71-76. doi: 10.13700/j.bh.1001-5965.2014.0053
Abstract:
Compared with the low earth orbit synthetic aperture radar (SAR) system, the moon-borne SAR is distinct from its unique imaging geometry, so the Doppler parameters estimation method is different from conventional pickaback and satellite-borne SAR. Precise jet propulsion laboratory (JPL) ephemeris wa...
Maneuvering target tracking with modified unbiased FIR filter
FU Jinbin, SUN Jinping, LU Songtao, ZHANG Yaotian
2015, 41(1): 77-82. doi: 10.13700/j.bh.1001-5965.2014.0068
Abstract:
In the field of maneuvering target tracking, the performance of Kalman filter(KF)and its variants is dependeds on the accuracy of the assumed process noise statistics. If the assumed process noise is not accurate, the performance of the KF and its improved algorithms will be degraded significantly. ...
Hybrid iteration sliding mode control for ultra-low altitude airdrop level off
LIU Ri, SUN Xiuxia, DONG Wenhan
2015, 41(1): 83-89. doi: 10.13700/j.bh.1001-5965.2014.0020
Abstract:
For the ultra-low altitude airdrop level off stage, many uncertain factors such as ground effect, sensor measurement errors and low altitude airflow interfere the precision of trajectory tracking, which exert serious threats on the aircraft safety and mission performance, a hybrid iteration sliding ...
Method of testability evaluation using hierarchical testability model
YIN Yuanwei, SHANG Chaoxuan, MA Yanheng, LI Gang
2015, 41(1): 90-95. doi: 10.13700/j.bh.1001-5965.2014.0029
Abstract:
The layered and modularized design is always used in complex electronic equipment, where the maintenance level and test requirement are both characterized by hierarchy configuration. Therefore, a novel evaluation approach was presented based on hierarchical testability model. The multi-signal flow g...
Intelligent decision-making algorithm based on bounded FART-Q
ZHOU Yanan, GONG Guanghong
2015, 41(1): 96-101. doi: 10.13700/j.bh.1001-5965.2014.0076
Abstract:
Fuzzy adaptive resonance theory (ART) with bounded side length was proposed to address the problem emerged while applying fuzzy ART to intelligent decision-making. Integrating the modified fuzzy ART and Q learning algorithm, bounded fuzzy ART-Q learning (FART-Q) intelligent decision-making network w...
Modeling and reinforcement decision analysis in air force combat based on data link
NIU Dezhi, CHEN Changxing, XU Haoxiang, LI Yongbin, WANG Zhuo, CHEN Qiang
2015, 41(1): 102-109. doi: 10.13700/j.bh.1001-5965.2014.0130
Abstract:
Force change problem during air combat course was studied. First of all, operation ability index of aircraft was converted to average combat level. Furthermore, in view of data link's influence on air combat and reinforcement force's joining to original force, differential equation model of every fo...
Offline signature verification based on ASIFT
TANG Youbao, BU Wei, ZHANG Enze, WU Xiangqian
2015, 41(1): 110-116. doi: 10.13700/j.bh.1001-5965.2014.0453
Abstract:
A novel offline signature verification method based on the affine and scale invariant feature transform (ASIFT) was proposed by analyzing the existing local invariant features and the property of the disguised signature. The method consists of the following steps, the preprocessing including image g...
Video encryption algorithm of content associated key
WANG Wei, HUANG Hao, XIE Changsheng, HAN Lin
2015, 41(1): 117-123. doi: 10.13700/j.bh.1001-5965.2014.0459
Abstract:
With the development of computer technology and video, display technology, there are new requirements of video encryption algorithm. A video content associated key concept was proposed and used in the encryption of video after the research of current video encryption algorithm's defects in video cop...
Synchronizing compensation control of electro-hydraulic load simulator using command signal of actuator
HAN Songshan, JIAO Zongxia, SHANG Yaoxing, WANG Chengwen
2015, 41(1): 124-132. doi: 10.13700/j.bh.1001-5965.2014.0052
Abstract:
Electro-hydraulic load simulator is a typical case of the force (torque) servo system which is strongly coupled with a hydraulic position system. How to eliminate the extraneous torque from motion disturbances is the key difficulty in electro-hydraulic load simulators. Based on theoretical analysis ...
Dynamic flight stability of a model dronefly in hovering and forward flight
XU Na, SUN Mao
2015, 41(1): 133-140. doi: 10.13700/j.bh.1001-5965.2014.0069
Abstract:
Insects usually keep hovering or forward flight. Thus the dynamic stability of the two types of flight is significant to study the insect flight. The dynamic flight stability of a model dronefly in hovering and forward flight was studied. On the basis of an averaged model and the small disturbance t...
Flow rate of nitrogen-rich air and influence factors for onboard air separation unit
SHAO Lei, LIU Weihua, FENG Shiyu, GU Yuankang, LIU Weipan
2015, 41(1): 141-146. doi: 10.13700/j.bh.1001-5965.2014.0080
Abstract:
The flow rate of a certain type onboard air separation unit to produce the nitrogen-rich air related with the flight height, inlet pressure, temperature and the nitrogen concentration was experimentally studied on a test apparatus. An empirical correlation to predict the flow rate of the nitrogen-ri...
Aeroelasticity quick analysis method of very propeller/flexible wing system
XIE Changchuan, ZHANG Lijuan, LIU Yi, YANG Chao
2015, 41(1): 147-153. doi: 10.13700/j.bh.1001-5965.2014.0025
Abstract:
The propeller's revolving slipstream passing wing changes the drag/lift property of the wing. For the hyper long endurance unmanned flight vehicles design, the slipstream effect should be analyzed for the aeroelasticity of the very flexible wing. The Prandtl revised blade element-momentum theory was...
Estimation of target's acceleration based on empirical wavelet transform
CHEN Hao, GUO Junhai
2015, 41(1): 154-159. doi: 10.13700/j.bh.1001-5965.2014.0036
Abstract:
Target's accelerations lead to spectrum shift and broadening of target's echo signal, resulting in the inaccuracy estimation of target's Doppler frequency with traditional pulse radar velocity measurement method. To overcome the effect of acceleration on pulse radar velocity measurement, an empirica...
Trajectory optimization of two aircrafts in collaborative passive target tracking
RAN Huaming, ZHOU Rui, WU Jiang, DONG Zhuoning
2015, 41(1): 160-166. doi: 10.13700/j.bh.1001-5965.2014.0039
Abstract:
To solve high accuracy requirement in collaborative passive tracking of two aircrafts, according to the geometric situation of the two aircrafts to the target, the effect of the geometric situation to the passive detection accuracy was analyzed, the formula of position dilution of precision (PDOP) w...
Decomposition and coverage of multi-UAV cooperative search area
YU Sinan, ZHOU Rui, XIA Jie, CHE Jun
2015, 41(1): 167-173. doi: 10.13700/j.bh.1001-5965.2014.0056
Abstract:
Coverage search of multi aircraft is a major task for unmanned aerial vehicle (UAV). After dividing the searching area, the problem turns into single UAV coverage search problem in each sub-area. This method will make the whole search problem simpler. The parallel searching strategy was analyzed in ...
Analysis method of iGPS measurement uncertainty spatial distribution
SUN Fulong, ZHAO Gang, WANG Wei, CHEN Lei
2015, 41(1): 174-180. doi: 10.13700/j.bh.1001-5965.2014.0044
Abstract:
The spatial distribution of iGPS measurement uncertainty was studied to help rapid assessment and layout optimization of iGPS measurement. According to the measurement model of iGPS, a typical two-station model of measurement uncertainty was established. Furthermore, a universal analysis method of i...
Simulation on stealth characteristics of X-tail near space airship
XIAO Houdi, LIU Longbin, LÜ Mingyun
2015, 41(1): 181-186. doi: 10.13700/j.bh.1001-5965.2014.0047
Abstract:
In order to reduce the radar cross section (RCS) of near space airship, the effect on the RCS of near space airship was studied, when its X-tail has different deformation angles. The RCS character effect of head, side and tail in the near space airship was simulated, when X-tail has different deform...