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7th International Conference on Structural Health Monitoring of Intelligent Infrastructure, SHMII 2015

作者： Zhou, W. Li, H. Dong, Y. Wang, A. Key Lab. of Structures Dynamic Behavior and Control of the Ministry of Education Harbin Institute of Technology Harbin150090 China School of Civil Engineering Harbin Institute of Technology Harbin150090 China National Key Laboratory of Science and Technology on Tunable Laser Harbin Institute of Technology Harbin150001 China

Optical fiber sensors have been proven that they have potential as ultrasonic guided waves sensor for structural health monitoring and damage detection. They can be used to receive acoustic emission signals from dynamic structural damages or guided waves propagating in waveguide and excited by ultrasonic actuators. Optical fiber sensors based on Mach-Zehnder interferometer were investigated in this work. Their sensing properties were explored experimentally using Lamb waves excited by a piezoelectric wafer in an aluminum plate. Spiral shape with different size was selected to increase their sensitivity. Experiments were also conducted to examine the voltage responses received by this type of sensor, and investigate results of tuning frequency. © 2015, International Society for Structural Health Monitoring of Intelligent Infrastructure, ISHMII. All rights reserved.

关键词： Structural health monitoring

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technology of shipboard two-way microwave time synchronization

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Journal of Beijing Institute of technology 2014年第4期23卷 511-518页

作者：付永杰李东光刘旭东 Science and Technology on Electormechanical Dynamic Control Laboratory Beijing Institute of Technology Unit 92493 of PLA Huludao

For the high precision time synchronization demand of ships, advantages and disadvantages of the present time transfer methods are analyzed, the two-way microwave time transfer （TWMTT） method is adopted to resolve the time synchronization problem in the Naval Ship Formation. After expounding the principle and system composition of TWMTT method, the various factors influencing the synchronous precision are analyzed, such as time-interval measurement error, TWMTT equipment delay error, signal propagation error in air, and signal delay error caused by shipping. To improve the time synchronization precision, all the error sources above are deduced with mathematical measures to definite the critical one, and the signal processing measures such as Pseudo code spread spectrum time comparison signal generation technology, FFT fast acquisition technology and precise tracking technology are used into the modem which is the core equipment of the TWMTT. And, calibration method of TWMTT equipment delay are developed. Through theoretical a- nalysis and simulation verification, the precision of shipboard two-way microwave time synchroniza- tion can reach 1 ns.

关键词： two-way microwave time transfer（TWMTT） time synchronization time delay error analysis

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Fuel-optimal trajectory design using solar electric propulsion under power constraints and performance degradation

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science China(Physics,Mechanics & Astronomy) 2014年第6期57卷 1090-1097页

作者： ZHANG Peng LI JunFeng GONG ShengPing School of Aerospace Tsinghua University Science and Technology on Aerospace Flight Dynamic Laboratory Beijing Aerospace Control Center

The fuel-optimal transfer trajectories using solar electric propulsion are designed considering the power constraints and solar array performance *** different performance degradation models including linear,positive and negative exponential degradations are used in the analysis of three typical rendezvous missions including Apophis,Venus and Ceres,*** optimal control problem is formulated using the calculus of variations and Pontryagin’s maximum principle,which leads to a bang-bang control that is solved by indirect method combined with a homotopic *** demonstrating the effects of the power constraints and solar array performance degradation on the power budget and fuel consumption,the time histories of the power profile and the fuel consumptions are compared for the three *** study indicates that it is necessary to consider the power constraints and solar array performance degradation for the SEP-based low-thrust trajectory design,espacially for long-duration outbound flights.

关键词： fuel-optimal trajectory solar electric propulsion power constraints performance degradation

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Self-calibration method for navigation systematical error by sparse optimization

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Journal of Beijing Institute of technology (English Edition) 2015年 24卷 147-151页

作者： Liu, Ye Zhao, Hua Cao, Jiang-Feng Zheng, Ai-Wu Liu, Lei Science and Technology on Aerospace Flight Dynamic Laboratory Beijing100094 China Beijing Aerospace Control Center Beijing100094 China Key Laboratory of Space Object Measurement Beijing100094 China

Detection for systematical error is needed in navigation system for all instruments. A new method for systematical error real-time detection and estimation is proposed by theory of sparse optimization and UKF. In this method, a sparse optimization procedure is introduced for the systematical error detection at each filter time step. It has less risk of calibration delay and diversion of systematical error than traditional methods, which makes the error detection and the state estimation more accurate. According to the theory analysis and simulation results, the new method can solve state and systematical errors simultaneously by virtue of the effective error detection. Thus, the accuracy and reliability of navigation system with multi-sensor can be improved. © 2015 Beijing Institute of technology.

关键词： Error detection

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Three-dimensional suboptimal guidance law for fly-over and shoot-down smart ammunition via virtual target

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Journal of Beijing Institute of technology 2014年第4期23卷 443-451页

作者：杨喆吴炎烜范宁军王正杰 National Key Laboratory of Science and Technology on Electro-mechanical Dynamic Control School of Mechatronic EngineeringBeijing Institute of Technology

An optimal burst height is required for the fly-over and shoot-down smart ammunition with an EFP warhead at the instant of explosion which brings a special requirement to the miss distance of the terminal guidance law. In this paper, a guidance law based on the virtual target scheme is proposed. First, the practical pursuit-evasion issue between the ammunition and the target with specific miss distance is transformed into a virtuai pursuit-evasion problem with zero miss distance. Secondly, a complete three-dimensional pursuit-evasion kinematics model is established without any simplifications. And then, a suboptimal guidance law is designed based on the θ-D method which has constraints of the elevation and azimuth angular velocity of the virtual line of sight （LOS）. Finally, in order to verify the performance of the proposed guidance law, three test cases are conducted. Numericai results show that under the proposed terminal guidance law, the smart ammunition not only can fly above the target with an optimal burst height but also have a smaller normal acceleration on the terminal trajectory.

关键词： three-dimensional guidance law virtual target fly-over and shoot-down θ-D method

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synchronization of coupled reaction-diffusion neural networks with mixed delays

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Complexity 2016年第S2期21卷

作者： Ping He Yangmin Li Department of Electromechanical Engineering Faculty of Science and Technology University of Macau Taipa Macao Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical Engineering Tianjin University of Technology Tianjin China

The reaction-diffusion neural network is often described by semilinear diffusion partial differential equation (PDE). This article focuses on the asymptotical synchronization and synchronization for coupled reaction-diffusion neural networks with mixed delays (that is, discrete and infinite distributed delays) and Dirichlet boundary condition. First, using the Lyapunov–Krasoviskii functional scheme, the sufficient condition is obtained for the asymptotical synchronization of coupled semilinear diffusion PDEs with mixed time-delays and this condition is represented by linear matrix inequalities (LMIs), which is easy to be solved. Then the robust synchronization is considered in temporal-spatial domain for the coupled semilinear diffusion PDEs with mixed delays and external disturbances. In terms of the technique of completing squares, the sufficient condition is obtained for the robust synchronization. Finally, a numerical example of coupled semilinear diffusion PDEs with mixed time-delays is given to illustrate the correctness of the obtained results. © 2016 Wiley Periodicals, Inc. Complexity 21: 42–53, 2016

关键词： asymptotical synchronization synchronization coupled reaction-diffusion neural networks linear matrix inequality (LMI) partial differential systems (PDSs) mixed delays

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Method for fast transform of pulsed laser peak power

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Beijing Ligong Daxue Xuebao/Transaction of Beijing Institute of technology 2015年 35卷 58-61页

作者： Gao, Zhi-Lin Chen, Hui-Min Cai, Ke-Rong Science and Technology on Electromechanical Dynamic Control Laboratory Beijing Institute of Technology Beijing100081 China Shanghai Electro-Mechanical Engineering Institute Shanghai201109 China

The variation law of echoed laser power in the process of fuze encounters the target was analyzed, and a method of simulating the rapid change of echoed laser power by changing the supply voltage and the pulse signal's width of pulse semiconductor laser was put forward. PFGA was used as the controller to command the high speed digital-analog converter, in order to realize fast switching of semiconductor laser drive circuit's supply voltage in submillisecond level. Experiment results show that the laser power can be adjusted rapidly and accurately within 100 μs. © 2015, Editorial Department of Transaction of Beijing Institute of technology. All right reserved.

关键词： Semiconductor lasers

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Micro-actuator device characteristics study on lead-based antiferroelectric thick films of (Pb, La)(Zr, Ti)O3

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Gongneng Cailiao/Journal of Functional Materials 2015年第19期46卷 19060-19064页

作者： An, Kun Chen, Donghong He, Jian Chou, Xiujian Xue, Chenyang Zhang, Wendong National Key Laboratory for Electronic Measurement Technology North University of China Taiyuan China School of Computer Science and Control Engineering North University of China Taiyuan China Key Laboratory of Instrumentation Science & Dynamic Measurement of Ministry of Education North University of China Taiyuan China

Taking the metal alkoxide as a precursor, the wafer grade of (Pb, La)(Zr, Ti)O3(PLZT) anti-ferro-electric thick films were fabricated by the sol-gel process on silicon substrate. Based on the strong field induced strain and the sharp phase switching of anti-ferroelectric materials and combined with key technologies of micro-nano compatible manufacturing, the microcantilevers was presented with excellent large strain capacity, rapid response speed, low drive voltage. The experimental results of 3 excitation modes showed that the maximum displacement and velocity of microcantilevers under the fixed frequency (square) is several times larger than that under the sweep (or scan) frequency. The phase transition of anti-ferroelectric materials were so much more excited underthe fixed frequency (square) than that under the sweep frequency that caused the larger strain capabilities and higher response speed in the micro-cantilevers, which was a new technical approachto design micro-actuators with characteristics of large drive displacementand rapid response. © 2015, Chongqing Functional Materials Periodical Press Co. Ltd. All right reserved.

关键词： Thick films

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dynamic characteristics simulation for terminal trajectory of bomb parachute system in blockade and control ammunition

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Binggong Xuebao/Acta Armamentarii 2015年 36卷 289-294页

作者： Chen, Qing-Sen Song, Rong-Chang Guan, Ping Hao, Yuan Cui, Hai-Bin Science and Technology on Electromechanical Dynamic Control Laboratory Beijing Institute of Technology Beijing100081 China The Huaihai Industrial Group Corporation Limited ChangzhiShanxi046000 China

The blockade and control ammunition based on grenade platform is required to decelerate and despin after launching. Because of its relatively high initial velocity and rotating speed, the robustness of the parachute cord within a limited space should also be considered. The rigid multi-body dynamics method is used to study the dynamic characteristics of terminal trajectory of bomb parachute system in blockade and control ammunition. Through the stress analysis, dynamic modeling and computer-aided simulation of the blockade and control ammunition. The effect of the main parachute deployment time on ballistic characteristics and tension of the main parachute cord, and the despinning characteristics of the blockade and control ammunition are simulated and analyzed. The results show that the terminal trajectory of blockade and control ammunition meets the design requirements, and the despinning rotors can keep the despinning to a desired value. © 2015, China Ordnance Society. All right reserved.

关键词： Trajectories

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Correcting algorithms of the spinning projectile attitude based on the background magnetic field compensation

Correcting algorithms of the spinning projectile attitude ba...

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2nd International Conference on Precision Mechanical Instruments and Measurement technology, ICPMIMT 2014

作者： Qi, Ke Yu Xiang, Chao Bu, Xiong Zhu Shao, Jun Yu Science and Technology on Electromechanical Dynamic Control Laboratory Xi'an China Shanghai Electro-Mechanical Engineering Institute Shanghai China School of Mechanical Engineering Nanjing University of Science and Technology Nanjing China

ISBN: (纸本)9783038351948

At present, traditional navigation method could not provide long-time stability attitude information for the high spinning projectile because of drift errors of micro-inertial sensors. Meanwhile, the projectile attitude measuring method with respect to the earth's magnetic field is still auxiliary. The principle of characteristic ratio algorithm and compensation model of the background magnetic field for the spinning projectile are been introduced. To realize the high accuracy attitude measuring of the projectile, a new correcting method is proposed. The detail correcting steps are derived with the linear interpolation theory and iterative algorithm. On this basis, numerical simulation is conducted combining with projectile's flight rules. The results show that the corrected attitude angles errors are within ± 0.5°, and attitude update rate increased obviously. The calculating results could better describe the whole real roll motion. The proposed correcting method is significantly effective. © (2014) Trans Tech Publications, Switzerland.

关键词： Projectiles

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