Zhang X.,Luoyang Opto Electro Technology Development Center |
Zhang X.,University of Victoria |
Liang X.G.,Luoyang Opto Electro Technology Development Center
Advanced Materials Research | Year: 2013
Focusing on a nonlinear longitudinal dynamical model for air-breathing hypersonic flight vehicles (AHFV), we propose a state feedback linearized model on a nominal trim condition. To stabilize the flight of an AHFV in the presence of external disturbances, a new H∞ based Linear Quadratic Regulator (LQR) control law with pole placement is designed. Indexes for H∞ performance, quadratic performance and pole placement are considered together. As a result, the robustness of system is improved and the AHFV system is effectively stabilized. Numerical simulation shows that the controller can effectively stabilize the AHFV system with some disturbances and assign the poles into a desired region.
Cao X.,Luoyang Opto Electro Technology Development Center |
Li H.,Beihang University
28th Congress of the International Council of the Aeronautical Sciences 2012, ICAS 2012 | Year: 2012
A nonlinear system model of maneuvering target detection was introduced. To estimate offset angles of pitch and azimuth, relative velocity of missile and target, and distance information while detecting maneuvering target, extended Kalman filter algorithm was introduced. Simulations of nominal trajectory and extreme trajectory shows that the proposed system model and filter design approach can deal with partial information missing problems in the real flight condition and maintain good tracking accuracy for certain time even in extreme blocking situation.
Du B.,Luoyang Opto electro Technology Development Center |
Jia W.,Luoyang Opto electro Technology Development Center
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2011
Joule-Thomson coolers have been widely used in infrared detectors with respect to compact, light and low cost. For self-regulating Joule-Thomson cooler, its performance is required to be improved with the development of higher mass and larger diameter of focal plane infrared detectors. Self-regulating Joule-Thomson coolers use a limited supply of high pressure gas to support the cooling of infrared detectors. In order to develop Joule-Thomson coolers with a given volume of stored gas, it is important to study on fluid flow and heat transfer of Joule-Thomson coolers coupled with infrared detectors, especially the starting time of Joule-Thomson coolers. A serial of experiments of Joule-Thomson coolers coupled with 128×128 focal plane infrared detectors have been carried out. The exchanger of coolers are made of a d=0.5mm capillary finned with a copper wire. The coolers are self-regulated by bellows and the diameters are about 8mm. Nitrogen is used as working gas. The effect of pressure of working gas has been studied. The relation between starting time and pressure of working gas is proved to fit exponential decay. Error analysis has also been carried. It is crucial to study the performance of Joule-Thomson coolers coupled with infrared detectors. Deeper research on Joule-Thomson coolers will be carried on to improve the Joule-Thomson coolers for infrared detectors. © 2011 SPIE.
Lv Y.,Luoyang Opto electro Technology Development Center |
Meng Q.,Henan University of Science and Technology
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2011
Planar InGaAs/InP p-i-n photodiodes have been successfully fabricated, and its spectral response, current-voltage characteristic, photogenerated signal and noise were measured at 300 K and 77 K with the blackbody temperature fixed at 900 K. It was found that the measured voltage signals reduced from 14.0 mV to 7.0 mV when the temperature decreased from 300 K to 77 K. All measured results at 77 K show that the peak voltage responsivity of InGaAs detector is R vp= 2.41x107 V/W, and its peak detectivity D p* = 1.51x1012 (cmHz)1/2/W. Measurement of transmittance spectral indicated that the transmittance rate is over 80% at middle wavelength range. The results show that short wavelength infrared InGaAs detector can be integrated with middle wavelength infrared detector to form dual-band detector worked at liquid nitrogen temperature. © 2011 Copyright Society of Photo-Optical Instrumentation Engineers (SPIE).
Zhang G.,Luoyang Opto Electro Technology Development Center |
Si J.,Luoyang Opto Electro Technology Development Center |
Wang L.,Luoyang Opto Electro Technology Development Center
Hongwai yu Jiguang Gongcheng/Infrared and Laser Engineering | Year: 2012
A parametric study of the etching of InSb was performed in high density plasma (HDP) using inductively coupled plasma (ICP) system. To obtain high etch rate of InSb with smooth surface, Cl 2 gas was introduced to the CH 4/H 2/Ar gas mixture. The etch rate of InSb increased linearly with the Cl 2 content and the ICP power. However, the etched surface became roughened with the Cl 2 content exceeding 12% or the ICP power higher than 900 W. The roughened surfaces with higher Cl 2 content or higher ICP power were both attributed to the local accumulation of the by-product InCl 3 which prohibited the uniform etching. Substrate temperature ranging from 20°C to 120°C had almost no effect on the etch rate and the etched surface roughness. InSb to SiO 2 selectivity during the ICP etching was higher than 6 and increased with the ICP power. With ICP etching condition optimized in the investigated range, etch rate of exceeding 500 nm/min with smooth etched surface and sidewall angles of about 80° were obtained.
Wang H.-H.,Northwestern Polytechnical University |
Chen H.-X.,Luoyang Opto Electro Technology Development Center
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2012
Infrared dome is one of the key components of an infrared guidance vehicle. The optical properties of the dome such as transmission rate, type size and precision will affect directly the detector performance and impact ultimately on the system, therefore the optical manufacturing process of infrared dome plays an important role. In this paper a general optical manufacturing process of infrared dome may be analyzed and modeled by object-oriented Petri net (OOPN). Based on the performance analysis, the model boundedness can be verified, the processing production efficiency, the utilizing efficiency of the equipment and other statistical results can be achieved to improve the manufacturing process. The OOPN method simplifies the model effectively, at the same time the model is easy to be analyzed and has good reusability and extensibility. Studying on optical manufacturing process of infrared dome is not limited to the specific types of materials, the modeling result can be used by the same operation unit. © 2012 SPIE.
Guo Z.,Luoyang Opto Electro Technology Development Center |
Liang X.,Luoyang Opto Electro Technology Development Center
2011 International Conference on Electronics, Communications and Control, ICECC 2011 - Proceedings | Year: 2011
Relaxed Stable Stability is a new way to rise the flying speed, distance and maneuverability of missile. The focus of this paper is on the pole placement controller design for RSS missile. First, a concise intrduction of RSS and pole placement controller and the vertical direction perturbation equations are described. Then a controller is developed. By using this, we simulate a missile model. Simulation results as well as stability analysis of RSS missile demonstrate the validity of the proposed scheme. © 2011 IEEE.
Zhang X.,Henan University of Science and Technology |
Meng Q.,Henan University of Science and Technology |
Yu Q.,Henan University of Science and Technology |
Zhang L.,Henan University of Science and Technology |
Lv Y.,Luoyang Opto electro Technology Development Center
Journal of Mechanical Science and Technology | Year: 2013
When exploring the buckling mechanism in indium antimonide (InSb) detector, the global square checkerboard buckling pattern reappears in finite element simulation results. The contributions from the three layered materials to the deformations along the Z-direction are systematically analyzed. Analysis of results shows that the buckling deformation originated from the thermal difference between silicon readout integrated circuits (silicon-ROIC) and the intermediate layer directly above. Furthermore, the buckling pattern is determined by indium bumps array. After passing through the 10 μm intermediate layer, the deformation amplitude is significantly reduced from 2.23 μm to 0.24 μm. Afterwards, passing upward through the 10 μm InSb chip, the maximal deformation is further decreased to 0.09 μm. © 2013 The Korean Society of Mechanical Engineers and Springer-Verlag Berlin Heidelberg.
Wang Q.,Northwestern Polytechnical University |
Li J.,Luoyang Opto Electro Technology Development Center
Journal of Theoretical and Applied Information Technology | Year: 2012
In this paper, based on possibilistic reliability theory, the hybrid variables structural reliability model, which includes fuzzy variables and interval variables, is researched. The hybrid variables structural reliability model is established based on possibilistic reliability theory. The analytical algorithms of minimum fuzzy reliability index and maximum failure possibility degree in hybrid variables structural reliability analysis are derived in detail. The constraint conditions of hybrid variables structural reliability model are analyzed. The reliability optimum design method of hybrid variables structure is researched. By evaluation of hybrid variables structural reliability through practical examples, it proved that, in the case of two uncertain variables coexisting, the theory presented in this paper is feasible and effective. And thus, it will have great significance in actual engineering, especially for reliability design of complex structures. © 2005 - 2012 JATIT & LLS. All rights reserved.
Geng D.,Luoyang Opto Electro Technology Development Center |
Zheng K.,Luoyang Opto Electro Technology Development Center |
He Y.,Luoyang Opto Electro Technology Development Center
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2014
In the hybrid InSb focal plane arrays(FPAs) chip fabrication process, the fracture of chips under thermal shock is the main factor of InSb FPA chip failure and the yield of InSb FPAs chip has been limited by the high fracture probability. In this paper, a novel equipment for thermal shock experiment has been designed. Using this equipment, the thermal shock experiment on InSb FPAs was carried out and the position and distribution of cracks in InSb FPAs chip was obtained. It was found that thermal mismatch stress and process damage are two main causes responsible for InSb FPAs chip's fracture by analyzing crack and process factors. By selecting suitable underfill materials, optimizing the curing process, controlling the feed rate of wafer cutting, reducing thermal mismatch stress and avoiding the process damage induced in process, the cracking probability of InSb FPAs chip has been decreased. Thus, the yield of InSb FPAs chip was increased significantly. © 2014 SPIE.