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Jiang B.,Mechanical Engineering College | Qi X.-L.,Mechanical Engineering College | Liu J.,Armed Police Engineering University | Jia B.,Military Representative Bureau
Sensors and Transducers | Year: 2014

To meet the pressure sensors used in special harsh environments, the MEMS piezoresistive pressure sensor design is proposed that the technology is more mature and more extensive used. The research of Piezoresistive sensor chip is done based on the analysis of sensor principle. The chip substrate material is selected combine with the special environment. The range sensor chip design is done based on small deflection theory and silicon material diaphragm piezoresistive effect theory. In order to avoid resonance modal analysis of the diaphragm is done. The force-sensitive resistor strip and its layout in the diaphragm is designed combine with the round diaphragm stress distribution. Semi-open-loop mode bridge is choice based on the comparison of advantages and disadvantages of three bridge modes. Given the special environment of vibration, acceleration sensitivity calculations must be done to adapt vibration environments for pressure sensor. Theory basis in sensor design is full, design projects and parameters combine with special environmental closely, and the research will have important significance for further study of special environmental pressure sensor. © 2014 IFSA Publishing, S. L.

Xin Z.,PLA Military Transportation University | Xin Z.,Tsinghua University | Wu Z.,Armed Police Engineering University
Journal of Networks | Year: 2014

As the ant colony algorithm has the defects in robot optimization path planning such as that low convergence cause local optimum, an improved ant colony algorithm is proposed to apply to the planning of path finding for robot. This algorithm uses the search way of exhumation ant to realize the complementation of advantages and accelerate the convergence of algorithm. The experimental result shows that the algorithm of this paper make the optimization planning of robot more reasonable. © 2014 Academy Publisher.

Wu Q.,Armed Police Engineering University | Lu J.,68036 PLA Troops
Lecture Notes in Electrical Engineering | Year: 2016

To resolve the security problem existing in multilayer and multi-domain intelligent optical network, the multilevel and expansive security architecture was presented based on the classified description of threats, and the design of the syncretic mechanisms. Finally, the security model is described by a mathematical model based on hypergraph theory. That is, the edges represent security level; nodes represent the corresponding security technology. The proposed model simplified the complexity of security architecture and facilitated the analysis of future quantitative mathematical. © Springer India 2016.

Liu H.,Xi'an Jiaotong University | Huang Y.,Xi'an Jiaotong University | Huang Y.,Armed Police Engineering University | Zhao W.,Xi'an Jiaotong University | Lu B.,Xi'an Jiaotong University
Jixie Gongcheng Xuebao/Journal of Mechanical Engineering | Year: 2014

The load inertia ratio is important for performance analysis and design of computer numerical control (CNC) machine tools feed drive system. Under the high-speed and high-precision trends of machine tool, the optimization of the load inertia raitio become crucial. The systematic analysis of the relationship between the load inertia ratio and performance of its feed drive system is necessary, and a precise design method for inertia ratio is asked for. Using double mass mechanical model, an approach combined analytic and numerical simulation is presented. The relationship between inertia ratio and energy matching efficiency, relationship between inertia ratio and controller gain, and closed loop frequency characteristic, anti-disturbance dynamic stiffness under semi-closed and fully-closed loop control structures are analyzed respectively. Based on these analyses, a brief description of design approach is given. For CNC machine tool designer, methods to choose the optimal load inertia ratio based on specific performance requirements under multi-factors are formed, which bare theoretical and practical engineering values. © 2014 Journal of Mechanical Engineering.

Liu J.,Xi'an University of Technology | Zhou F.,Xi'an University of Technology | Liu F.,Xi'an University of Technology | Liu F.,Armed Police Engineering University
Dianli Xitong Baohu yu Kongzhi/Power System Protection and Control | Year: 2016

In order to ensure the high-efficiency and stable operation of the wind turbines, this paper presents compensation torque of fuzzy variable gain in torque control. The influence of mechanical torque fluctuation of wind turbines caused by random dither component of the tower shadow effect, wind shear, wind speed and reference rotation fluctuation calculated via optimal tip speed ratio on permanent magnet synchronous wind power system is alleviated effectively, the low frequency oscillation of wind power system is suppressed, and the stability of the system is ensured. It calculates accurate reference speed of maximum electromagnetic power by modifying the optimal tip speed ratio, and makes the unit run at the corresponding working point of maximum electromagnetic power. It truly achieves the maximum wind power tracking, by calculating the optimal tip speed ratio, considering the shafting friction loss. A direct-driven permanent magnet synchronous wind power system simulation platform is built in detail under Matlab/Simulink, and the correctness and effectiveness of the method is proved. © 2016, Power System Protection and Control Press. All right reserved.

Luo L.,Armed Police Engineering University
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2014

For the purpose of monitoring the attitude of aircraft, an angular measurement system using a MEMS heat convection accelerometer is presented in this study. A double layers conditioning circuit that center around the single chip processor is designed and built. Professional display software with the RS232 standard is used to communicate between the sensor and the computer. Calibration experiments were carried out to characterize the measuring system with the range of - 90°to +90°The curves keep good linearity with the practical angle. The maximum deviation occurs at the 90°where the value is 2.8°.The maximum error is 1.6% and the repeatability is measured to be 2.1%.Experiments proved that the developed measurement system is capable of measuring attitude angle. © 2014 SPIE.

Qi X.,Ordnance Engineering College | Liu J.,Armed Police Engineering University | Shan N.,Armed Police Engineering University
Jixie Qiangdu/Journal of Mechanical Strength | Year: 2013

Planar W-form spring is one important kind of MEMS (micro-electro-mechanical system, MEMS) component, which had been chiefly studied its coefficient of elasticity based on liner elastic theory up to now, but be short of elastoplastic deformation character study. According to the elastoplastic deformation theory, the analysis model of W-form spring has been established, and the deformation character of W-form spring has been studied adopting Ansys software. The largest tensile force and displacement in elastic deformation scope has been achieved, which has been validated by spring tensile experiment in 8% relative error. The influence of structure parameter of spring on the deformation has also been researched, obtaining the relationship between deformation property including largest elastic force, coefficient of elasticity and largest elastic displacement and parameter of spring such as wide, thickness and half clamp-angle, so the structural of W-form spring can be reasonably designed according to the dimension of tensile force elastic coefficient and space.

Wu Z.-W.,Armed Police Engineering University | Cheng P.,Beijing University of Technology | Fu H.-G.,Beijing University of Technology
Cailiao Rechuli Xuebao/Transactions of Materials and Heat Treatment | Year: 2014

Effects of quenching temperature on microstructure and mechanical properties of Fe-Cr-B-Al alloy containing 8%Cr, 1.5%B and 1.5%Al were investigated in the condition of oil-cooling quenching. The results show that the microstructure of as-cast Fe-Cr-B-Al alloy is consist of M2(B, C) (M=Fe, Cr, Mn), (Cr, Fe)7(C, B)3, martensite and pearlite. After quenching, the network eutectic borocarbides are broken and spheroidized, which lead to the increase of tensile strength and impact toughness of Fe-Cr-B-Al alloy. When quenching temperature exceedes 950°C, the matrix is transformed into martensite from the mixture of martensite and pearlite, and hardness of Fe-Cr-B-Al alloy increases. When quenching temperature is over 1050°C, borocarbides begin to coarsen. Fe-Cr-B-Al alloy quenched at 1050°C has good comprehensive properties.

Wu Q.,Armed Police Engineering University | Liu Q.,Armed Police Engineering University
Sichuan Daxue Xuebao (Gongcheng Kexue Ban)/Journal of Sichuan University (Engineering Science Edition) | Year: 2015

In order to solve the trust management problem of vehicles, a trusted model of secure routing of VANET for quantitative trust management based on Bayesian theory was proposed. In the proposed model, classified and dynamic management method of node trust was used. Meanwhile, the Beta distribution was used to describe the trust situation of the nodes based on the routing protocol framework of GeoDTN+Nav. The proposed model not only improved the security of routing, but also had the lower time complexity and good extensibility. The experimental results showed that, the trust model is effective and has good performance in the malicious nodes removal rate, the packet average arrival rate and the end-to-end average delay. ©, 2015, Editorial Department of Journal of Sichuan University. All right reserved.

Liu D.,Chang'an University | Liu D.,Armed Police Engineering University | Han L.,Chang'an University | Han X.,Chang'an University
Guangxue Xuebao/Acta Optica Sinica | Year: 2016

A classification method based on deep learning is proposed for the classification of high spatial resolution remote sensing images. The texture features of the images are calculated through nonsubsampled contourlet transform, the deep learning common model-deep belief networks (DBN) are used to classify the high spatial resolution remote sensing images based on spectral and texture features. The proposed method is compared with the DBN classification method based on single spectral information, the support vector machine (SVM) method and the traditional neural network (NN) classification method. Experimental results show that comparing with the single spectral information, the use of spectral and texture information can effectively improve the classification accuracy of high spatial resolution remote sensing images, and comparing with methods of SVM and NN, the DBN method can accurately explore the distribution law of the high spatial resolution remote sensing images and improve the accuracy of classification. © 2016, Chinese Lasers Press. All right reserved.

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