Chen A.,Soochow University of China |
Feng R.,North General Electronics Group Co. |
Zhuang X.,North General Electronics Group Co. |
Xu D.,Soochow University of China |
Guo S.,North General Electronics Group Co.
Chinese Journal of Sensors and Actuators | Year: 2017
The air damping of Micro-machined Wheel Angular Vibration Gyroscope is a main factor to influence the dynamic performance. A physical model is proposed and improved for the characterization of the slide film damping of drive mode based on adequate studies of the whole structure. A simplified model to calculate the squeeze film damping of sense mode is given by solving the Reynolds equation through the finite-difference method. The formulation is calculated in the 5 Pa~105 Pa range of pressure change, and the model is validated by comparing with the ANSYS results. The theoretical model computation and simulation results all shows that the squeeze film damping of sense mode is the main generation mechanism of the whole air damping in wheel angular vibration gyroscope. Effective ways to reduce the air damping effect is given from the perspective of structure design and circuit control. © 2017, The Editorial Office of Chinese Journal of Sensors and Actuators. All right reserved.
Pan H.,Shanghai JiaoTong University |
Jing Z.,Shanghai JiaoTong University |
Huang Z.,North General Electronics Group Co. |
Jin B.,Shanghai JiaoTong University
IEEE International Conference on Control and Automation, ICCA | Year: 2014
It is very difficult to restore natural geometry of the actual image from degraded observation. In this paper, to deal with approximation error and the turbulence casued by proximal splitting scheme, a generalized proximal conjugate gradient framework is proposed. To trade off approximate accuracy and computational complexity, an approximate solution is presented, which characterized by maintaining the sparse pattern of second-derivate information and considered a correcting stage with conjugate gradient. Some theoretical properties of the proposed method are discussed and presented. The numerical experiments of the proposed algorithm, in compassion to the favorable state-of-the-art methods, demonstrate the advantages of the proposed method and its great potential. © 2014 IEEE.
Wang S.,PLA Air Force Aviation University |
Song S.,North General Electronics Group Co. |
Huang J.,North General Electronics Group Co.
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2012
Improvement factor of bistatic radar suffers from the time and frequency synchronization, this is analyzed firstly in this paper. And then we design a field system which can fulfill the improvement factor measurement for bistatic radar. © 2012 Springer-Verlag.
Chai R.-X.,Xi'an Jiaotong University |
Guo C.,Xi'an Jiaotong University |
Yu L.,North General Electronics Group Co.
Materials Science and Engineering A | Year: 2012
Arrhenius-type constitutive equation considering strain compensation and BP neural network model are used to analyze the hot deformation behavior of XC45 steel. The experimental data are acquired from hot compression tests in Gleeble-1500 thermal-mechanical simulator in the range of temperature from 1053K to 1253K and strain rates from 0.01s -1 to 10s -1. The predictabilities of Arrhenius-type constitutive model and back propagation (BP) neural network model can be evaluated based on the correlation coefficient (R), root mean square error (RMSE) and average absolute relative error (AARE), and their predictabilities can be compared through several verification methods. It can be found that the BP neural network model is better in the predictable ability than the Arrhenius-type constitutive model. © 2011 Elsevier B.V.
Zhang J.,Nanjing University of Science and Technology |
Zhang J.,North General Electronics Group Co. |
Cheng X.,Nanjing University of Science and Technology |
Zhang H.,Nanjing University of Science and Technology
Nanjing Li Gong Daxue Xuebao/Journal of Nanjing University of Science and Technology | Year: 2013
To solve the problems of controlling the burst behind targets and adaptive burst points by detonating fuzes of penetrating warheads, a new method is proposed. The contact close signals obtained from inertia switches with redundance spring oscillator structure are used as the perception signals of controllers. Based on the mathematical model analysis of spring oscillator systems, the relationship between the movement trajectories of the mass blocks and the acceleration pulse is summarized under the condition of half positive sine pulse acceleration signals. An inertia switch is designed, which can perceive the state of projectile bodies in the processes of penetration, and the kinematic simulation analysis is performed by using ADAMS. Experiments of ammunitions penetrating monolayer and multilayer concrete targets are carried out using the inertia switches designed here. The acceleration signals and corresponding state signals of inertia switches during the process of penetration are collected. Experimental results show that the inertia switch designed here can reliably perceive the information of projectile bodies penetrating into and passing through the targets, which can be the control basis of the redundance burst points of fuzes and improve the burst reliability.
Wang Y.,North General Electronics Group Co Ltd |
Li C.,North General Electronics Group Co Ltd |
Yuan J.,North General Electronics Group Co Ltd
Qiangjiguang Yu Lizishu/High Power Laser and Particle Beams | Year: 2013
The quasi-optical feed system is a key component of the millimeter/sub-millimeter sensor. The design theory and methods of millimeter/sub-millimeter wave quasi-optical system are described. The varieties, functions and design process of quasi-optical passive devices are generalized. Then, the quasi-optical feed systems, which can realize the dual-polarized receiving and dual-mode composite operation, are constructed and the working principles are also given in detail. Ultimately, the corresponding millimeter-wave dual-reflector antenna is obtained through simulation and optimization, and the whole system with subreflector fixed and main reflector scanning is able to realize ±10°airspace coverage.
Qi X.,Northwestern Polytechnical University |
Shi Z.,North General Electronics Group Co. |
Zhu H.,Northwestern Polytechnical University
2013 9th Asian Control Conference, ASCC 2013 | Year: 2013
Attitude determination is strongly coupled with the estimation of unknown vibration parameters when the output of the inertial measurement unit (IMU) is corrupted by the vibration induced by the piston engine. The unknown vibration parameters in the attitude dynamics can degrade attitude accuracy of dead reckoning. In this paper, a dual estimation of attitude and parameters considering vibration is investigated for small UAV. The dynamic model contained attitude and parameters is established by state augmentation, and the observations are chosen as GPS velocity and heading. In order to employ hybrid extended kalman filter for dual estimation, Jacobian matrixes are formulated by linearizing the estimation model to propagate and update error variance. Since joint state estimation has tremendous computational loads, based on matrix blocking a state and parameter separated estimation is proposed to decouple the estimation of attitude and parameters. Simulation results show that the proposed method can give high precision attitude than the common filter without considering vibration. © 2013 IEEE.
Tang X.,North General Electronics Group Co. |
Long S.,North General Electronics Group Co. |
Liu Y.,North General Electronics Group Co.
Chinese Journal of Sensors and Actuators | Year: 2014
Based on the analysis of capacitive vibratory microgyroscope's interface circuit a low noise capacitive readout circuit is presented. All kinds of non-ideal factors are discussed. A high power supply rejection ratio of a low-noise amplifier based on continuous time capacitance-to-voltage technique is presented in this paper. Using high frequency modulation principle, the circuit can improve the resolution and dynamic range by canceling 1/f noise. This ASIC is designed and manufactured based on 0.5 μm analog CMOS process. The chip size is 3.5 mm×3.4 mm. Measurement shows that the capacitive readout circuit noise floor is -117.14 dB, When the gyro range is ±300 °/s, resolution can be achieved 0.00035 °/s.
Gou Y.,Xidian University |
Zhang S.,North General Electronics Group Co. |
Chen G.,Xidian University
Jixie Gongcheng Xuebao/Journal of Mechanical Engineering | Year: 2015
Multistable mechanisms can stay at multiple stable equilibrium positions without power input, and get more and more widely use in many regions. Fully compliant multistable mechanisms have some advantages such as free of assembly, frictionless, lower power consumption, and so on, but they are difficult to design because of the stress concentration and nonlinear characteristics caused by the large deformation of the flexible segments. A design approach is presented for a type of fully compliant sexastable mechanism, which possesses six stable equilibrium positions, employing a compliant structure and two compliant bistable mechanisms with different snap-through forces. The model of the compliant structure is built by pseudo-rigid-body model to achieve the force-deflection characteristics. The force-deflection curves of the two components are compared to obtain the stability criterion for the sexastable mechanism, avoiding nonlinear analysis. Formulas are proposed to determine the stiffness arrange of the flexible segments of the compliant structure, which is the basis of the size parameters design for the flexible segments. A design example is given and the finite element analysis by ANSYS software and the prototype test prove the feasibility of this design approach. ©, 2015, Editorial Office of Chinese Journal of Mechanical Engineering. All right reserved.
Ding X.,Nanjing University of Science and Technology |
Zhu W.,Nanjing University of Science and Technology |
Gao X.,North General Electronics Group Co. |
Hua G.,North General Electronics Group Co. |
Li J.,Nanjing University of Science and Technology
Fuel Processing Technology | Year: 2015
Solid oxide fuel cells (SOFCs) as alternatives for energy conversion have exhibited some unique advantages such as wide fuel flexibility, high energy efficiency and exhaust heat. An innovative composite cathode for SOFCs consisting of a high conductive La0.7Sr0.3CuO3 - δ (LSCu) electrode backbone infiltrated by nano and Ba0.5Sr0.5Co0.8Fe0.2O3 - δ (BSCF) particles with high electro-catalytic activity has been successfully fabricated by a simple solution infiltration process. The effect of BSCF nano catalyst on the electrochemical activity and stability of LSCu cathode was investigated and the inherent oxygen reduction reaction (ORR) mechanism is discussed. The polarization resistance is 0.043 Ω cm2 for 15 wt.% BSCF infiltrated LSCu cathode, and is reduced ~ 92.6% to that pure LSCu (0.58 Ω cm2) at 700 °C. The short term stability demonstrates that the electrochemical activity can be further improved in the first period about 40 h at 700 °C. After operated for 70 h, the electrochemical performance of the composite cathode became stable. A conductive scaffold (e.g. LSCu) modified with a highly catalytic nano particles (e.g. BSCF) is an attractive approach to fabricate cathodes with high electrochemical performance and stability. © 2014 Elsevier B.V. All rights reserved.