China Airborne Missile Academy
China Airborne Missile Academy
Zhao J.,China Airborne Missile Academy |
Ren W.,China Airborne Missile Academy
Jinshu Rechuli/Heat Treatment of Metals | Year: 2017
High temperature annealing test of two batches of DT4C pure iron parts was carried out in vaccum hydrogen annealing furnace. Effects of annealing temperature and cooling speed on dimension and coercivity of the parts were investigated. The results show that the magnetic coercive force decreases significantly when the annealing temperature is 1050-1150℃, however the dimensions change irregularly within the maximum shrink rate of 0.20% and the maximum expansion rate of 0.27%. For the magnetic coercive force unqualified parts, but its size error is meet the requirements, it can be annealed at 1050-1150℃ to reduce the magnetic coercive force. For the magnetic coercive force unqualified raw material, the blank should be annealed at 1050-1150℃, then the machined parts are subjected to stress relief annealing at 900℃. When annealing at 1050 to 1150℃, the cooling rate can be increased to about 120℃/h between the temperature range from 1120℃ to 900℃, in order to shorten the processing cycle. © 2017, Editorial Office of "Jinshu Rechuli". All right reserved.
Wang J.,China Airborne Missile Academy
Hongwai yu Jiguang Gongcheng/Infrared and Laser Engineering | Year: 2010
The time performance of region labeling algorithm is very important for precision guidance based on image. However, common region labeling algorithms can not meet the requirements of real-time image processing. By analyzing the current image labeling technologies, a technique using segment to record the connective area was proposed in this paper, connective closure and information related to the target could be computed during a one-time image scan. The coordinates of target edge pixels were recorded to computer target's features such as centroid, area, track and grey etc. as labeling. Then, the algorithm's conceptions and realization step were presented. Experimental results show that the proposed algorithm is capable of labeling targets in the image of 128 × 128 size in 0.4 ms with TMS320C6414 600 MHz simulator, and is more efficient, correct and stable compared with the other algorithm. It can well meet the timer performance requirements of real-time processing, and is applicable in high speed target capture and tracking.
Jin Q.,China Airborne Missile Academy
Journal of Applied Optics | Year: 2014
For the wide use of micro-spectrometer in diverse applications, its core device, torsion-type micromachined scanning gratings, were designed, fabricated and characterized. In order to obtain large scanning range and low resonant frequency at low driving voltage, the structure without additional starting electrodes was designed and studied by silicon-on-insulator (SOI) fabrication technology. The micromachined scanning gratings fabricated by SOI wafers were characterized, which prove that the micromachined scanning gratings has good modulation performances. The maximum deflection angles can reach ±4.8°, corresponding to a total optical scanning range of 19.2°at a driving voltage of 25 V.
Li J.-X.,China Airborne Missile Academy
Xi Tong Gong Cheng Yu Dian Zi Ji Shu/Systems Engineering and Electronics | Year: 2011
The one-dimensional clustering range resolution algorithm is a common stable ambiguity resolution in radar detection. The one-dimensional algorithm can acquire the unambiguous range by optimizing the least cost error. Based on the idea of reducing the range error step-by-step, a three-step-search algorithm is presented to solve the range ambiguity. First three different range errors are given corresponding to the radar system parameters, then the cost error is demanded to reduce gradually, meanwhile the ambiguity region is shrunk compared with the preceding region until the ambiguous range is acquired. The experimental results show that the three-step-search algorithm is efficient for range ambiguity resolution.
Liu W.,China Airborne Missile Academy
Hongwai yu Jiguang Gongcheng/Infrared and Laser Engineering | Year: 2013
The performance of InSb detectors with a nodic oxide and photo-CVD oxide had been compared in this paper. It showed that leak current of detectosr with anodic oxide was less than those with photo-CVD oxide, and breakage voltage of die former detectors was as much as 5 times of the latter ones, but the photocurrent and impedance of the former ones was the same as the latter. The results of capacitance-voltage (C-V) characteristics showed mat fixed charge density of the anodic detectors was 2×1011 cm-2, and the latter was 1.5×1011 cm-2. After ageing experiment, when inversion bias was 1V, the change rate of leak current ratio of the former was only 50% of the latter, while the photocurrent of detectors with both methods increase, which was possible related to photosensitive area's expansion. The anodic oxide passivation of detector had the three advantage of the process control, the fabricate uniformity and the stability of interface state.
Qi G.,China Airborne Missile Academy
Guti Dianzixue Yanjiu Yu Jinzhan/Research and Progress of Solid State Electronics | Year: 2015
A design of LTCC filter working in L-band was presented in this paper. With multilayer LTCC technology, dual layer coupled stripline resonators and three resonators using inductor feedback were designed to decrease the volume of filter. With the method of adding zero, the better stop-band performance was shown. The performance of the filter is realized: insertion loss, less than 1.2 dB, 2.4~2.5 GHz; attenuation, more than 20 dB, 1.7~1.9 GHz and 7.2~7.5 GHz. The results are in good accordance with the simulation. The dimension of filter is 1.6 mm×0.8 mm×0.6 mm. ©, 2015, NUAA Printing House. All right reserved.
Zhang S.,China Airborne Missile Academy
Fenmo Yejin Jishu/Powder Metallurgy Technology | Year: 2016
This article through to the foam metal domestic and foreign development survey introduction, the primary coverage included the foam metal basic concept, the preparation method, the aluminum foams, the magnesium foams, the titanium foams, the copper foams, the iron foams preparation and the application research, the foam metal characteristic and the application and so on, It has a comprehensive understanding to the foam metal development present situation, the research and the application. © 2016, University of Science and Technology Beijing. All right reserved.
Xu Y.,Northwestern Polytechnical University |
Liang X.,China Airborne Missile Academy
International Journal of Digital Content Technology and its Applications | Year: 2011
Active radar/infrared (IR) compound guidance technology has become a hot research content of compound guidance field. According to the characteristics and the engineering application of active radar/IR composite seeker system, in this paper, a distributed flow of information fusion for Radar/IR composite seeker was established. First the observation data of the two seekers were pretreated, including time and space registration and outlier elimination of the observation data. After that, the Federated Filter (FF) was used to setup an information fusion algorithm of radar/IR composite seeker. According to the different characteristics of radar and IR system, the Extended Kalman Filter (EKF) algorithm and the Pseudo-linear Kalman Filter (PLKF) algorithm were used to design radar and IR local filter respectively. The simulation results show that this information fusion algorithm provides significant improvement in the tracking precision of the radar/IR composite seeker system, and it has good real-time performance and stability.
Shang H.,China Airborne Missile Academy
Guangxue Jishu/Optical Technique | Year: 2013
Histogram-based particle filters for visual tracking have obtained success in many challenging tasks, but the computational inefficiency in evaluating the observation likelihood limits their use for real-time applications. A fast particle tracking method is proposed to this problem building on the integral histogram technique, with which the likelihood for each candidate can be computed efficiently by a few table lookup operations. As a result, the proposed method can employ a large number of particles to ensure the robustness while achieving the ability of tracking in real-time. Experimental results show that the method is computationally superior to the conventional particle tracking method.
Shen Z.-B.,National University of Defense Technology |
Tang G.-J.,National University of Defense Technology |
Zhang L.,China Airborne Missile Academy |
Li X.-F.,Central South University
Computational Materials Science | Year: 2012
This paper studies free vibration of double-walled carbon nanotubes (DWCNTs) based nanomechanical sensor under initial axial stress. A bridged DWCNT carrying a nanoparticle at any position of the outer tube is modeled as two clamped nonlocal Euler-Bernoulli beams, and the interaction between two tubes is governed by van der Waals force. For comparison, a bridged single-walled carbon nanotube (SWCNT) based nanomechanical sensor is considered in a similar way. Using the transfer function method, the critical buckling stress and natural frequencies of these nanomechanical sensors are computed. Under small initial stress, the effects of the attached nanoparticle, and the small scale parameter on the frequency shift are discussed. The obtained results show that when the mass of the nanoparticle increases or its location is closed to the beam center, the natural frequency decreases, but frequency shift increases. Initial tensile stress increases the natural frequency, while initial compressive stress decreases the natural frequency. In comparison with SWCNT sensor, DWCNT is more stable, but less sensitive for smaller attached mass. Obtained results are helpful to the design of DWCNT-based resonator as nanomechanical sensor. © 2012 Elsevier B.V. All rights reserved.