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Improving on HEED protocol of wireless sensor networks with sleep scheduling algorithm

Journal of Information and Computational science 2015年第13期12卷 5163-5173页

作者： Duan, Yabo Song, Chengtian Xu, Lixin Science and Technology on Electromechanical Dynamic Control Laboratory Beijing Institute of Technology Beijing China

Wireless Sensor Networks together hundreds or thousands of sensors allow users to monitor a remote areas. Improving energy efficiency while ensuring a certain coverage ratio in Wireless Sensor Networks (WSNs) is an extremely challenging issue. In some long-term monitoring applications of WSNs, where full coverage is not required, nodes can go to sleep mode to reduce energy consumption and increase network lifetime. In this paper, we propose three sleep scheduling algorithms based on HEED (Hybrid Energy-Efficient Distributed clustering) algorithm: Fixed Node Degree (FND) algorithm, dynamic Node Degree (DND) algorithm and dynamic Node Degree combined with Remaining Energy (DNDRE) algorithm. Our primary goal is to maximize the network lifetime while guaranteeing coverage ratio of the entire WSNs. Furthermore, we propose a simple and practical coverage ratio calculation method. We find the DNDRE performs the best in three sleep scheduling algorithms. ©, 2015, Journal of Information and Computational science. All right reserved.

关键词： Scheduling algorithms

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Design and realization of hardware-in-the-loop simulation system for pulsed laser fuze

Design and realization of hardware-in-the-loop simulation sy...

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International Conference on Information sciences,Machinery,Materials and Energy（ICISMME 2015）

作者： Zhilin Gao Huimin Chen Kerong Cai Science and Technology on Electromechanical Dynamic Control Laboratory Beijing Institute of Technology Shanghai Electro-Mechanical Engineering Institute

Laser fuze has advantages of anti electromagnetic interference and high accuracy of measuring distance,will become an important development direction of future *** paper constructs the hardware-in-the-loop simulation system of pulsed laser *** laser echo characteristic parameters of different encounter conditions based on the research of the environmental factors,target characteristics and the missile target encounter conditions *** take the characteristic parameters as the simulation parameters of laser *** the help of the echo signal simulator to simulate the processing of missile target *** echo signal calibration system is used to calibrate the output laser power of the echo signal *** experimental results show that: under the condition of laboratory,the system can realize the accurate simulation of the laser echo signal as well as has a certain reference value for the design of laser fuze.

关键词： Laser Fuze Hardware-in-the-loop Simulation Echo Signal Solve Echo Signal Simulation Echo Signal Calibration

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Three-dimension micro magnetic detector based on GMI effect

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Journal of Beijing Institute of technology 2014年第2期23卷 143-146页

作者：魏双成邓甲昊韩超杨雨迎 Science and Technology on Electromechanical Dynamic Control Laboratory School of Mechatronics EngineeringBeijing Institute of Technology

The giant magneto-impedance（GMI）effect of amorphous wire was analyzed *** amorphous wire had strong GMI effect in the stimulation of sharp pulse of 680kHz and18 mV.A pulse generator was designed to provide high frequency pulse to a magnetic impedance（MI）*** induced voltage on the pickup coil wound on the amorphous wire was sampled and held with a detect circuit using analog switch.A stable magnetic sensor was constructed.A three-dimension micro magnetic field detector was designed with a central controller *** stability and sensitivity were obtained in the MI sensor with the detect *** results showed that the resolution of the detector was 1nT in the full scale of±2 Oe and the detector worked stably from the room temperature to about 80℃.A small ferromagnetic target was detected by the three-dimension detector in laboratory environment without magnetic *** target moving direction was ascertained with the wave shape of axis parallel in that direction.

关键词： giant magneto-impedance（GMI）effect amorphous wire three dimension detector pulse generator analog switch

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Simulation of characteristics of cloud and fog echo for pluse laser fuze

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Guangxue Jingmi Gongcheng/Optics and Precision Engineering 2015年 23卷 1-7页

作者： Wang, Feng-Jie Chen, Hui-Min Science and Technology on Electromechanical Dynamic Control Laboratory Beijing Institute of Technology Beijing100081 China

Pulse laser fuze is susceptible to the interference of natural environment, such as cloud and fog, and easy to produce a false alarm. Therefore, this paper researches the cloud and fog echo characteristics of the pulse laser fuze. On the basis of Mie scattering theory, a pulse laser transmission model for the cloud and fog is established by using Monte Carlo simulation. The cloud and fog echoes in two conditions are simulated. The first condition is that both pulse laser fuze and target are in the inside of cloud and fog, and the other is that the target is in the inside of cloud and fog and the pulse laser fuze in the outside. At the first condition, the echo signals are acquired when the distance between pulse laser fuze and target is 10 m and the visibility are 1, 3, 5 and 10 m, respectively. At the second condition, the dynamic echo characteristics are obtained when the distance between pulse laser fuze and target is 10 m, the visibility is 3 m and the cloud and fog boundaries are 0, 1, 3, 5, 7and 9 m, respectively. Moreover, it analyzes the influences of cloud and fog parameters and position, on the cloud and fog echo, and the waveform difference of cloud and fog echo and target echo. This research provides the theoretical support for the anti-interference of pulse laser fuzes. © 2015, Chinese Academy of sciences. All right reserved.

关键词： Monte Carlo methods

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Design and implementation of an FFT phase difference measuring method

Design and implementation of an FFT phase difference measuri...

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2014 International Conference on Sensors Instrument and Information technology, ICSIIT 2014

作者： Zhu, Xiong Wei Chen, Hui Min Science and Technology on Electromechanical Dynamic Control Laboratory Beijing Institute of Technology Beijing 100081 China

ISBN: (纸本)9783038350392

The conventional phase difference measuring methods in the phase-shift laser range finder are usually implemented with complex hardware circuits and phase discrimination algorithm. In this paper an FFT phase difference measuring method is designed and implemented based on STM32F407VG microcontroller. This method takes the advantage of the pre-set and fixed frequency of the beat signal by setting the analog-to-digital conversion rate precisely and making the input data length of FFT integral multiples of the beat signal period. In this way spectrum correction is no need. The hardware circuits and phase discrimination algorithm is simplified. The test results show that the phase difference measuring accuracy of 1/12000 is achieved. © (2014) Trans Tech Publications, Switzerland.

关键词： Fast Fourier transforms

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Thermodynamics study of laser detector with high rotation speed

Thermodynamics study of laser detector with high rotation sp...

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作者： Yue, M.H. Chen, H.M. Science and Technology on Electromechanical Dynamic Control Laboratory Beijing Institute of Technology Beijing100081 China

In this paper, thermodynamics properties of a laser detector applied in 105 mm shrapnel with high rotation speed have been explored. In outer trajectory, aerodynamic heating usually generates because of viscosity, and this is strengthened by high rotation speed of the shrapnel. Thermal strain may occur, which will influence the overall power of the detector and shrapnel. The temperature has been computed by computational fluid dynamics method, and ANSYS Workbench has been applied to obtain thermal strain. In order to disclose the effect of rotation, comparison among simulation results in different conditions are carried out. It is figured out that the temperature increase does not exceed the limit of optical material (polymethyl methacrylate), so the function of laser detector and the power of shrapnel will not be affected. This paper demonstrates the feasibility of material choice of laser detector optical systems. It has important theoretical meaning and practical application value for the design of conventional ammunition laser detector. © 2014 W. S. Maney & Son Ltd.

关键词： Computational fluid dynamics

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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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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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Time-frequency domain properties on a compact multi-port IR-UWB antenna

Time-frequency domain properties on a compact multi-port IR-...

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Microwave, MTT-S International Symposium

作者： Hong-Li Peng Jian Ping Zhao Ni Ma Jinlong Zou Junfa Mao Key Lab of Ministry of Education for Research of Design and EMC High Speed Electronic Systems Shanghai Jiao Tong University Shanghai China Science and Technology on Electromechanical Dynamic Control Laboratory Xi'an China

A novel compact multi-port impulse radio ultra wideband (IR-UWB) antenna is presented in this paper. Its EM simulated models is developed through properly designed magneto-electric dipole. The time-frequency domain properties of this antenna for its specific multi-port excitations are studied in details by using simulations. Its VSWR and gain patterns are obtained and verified by the measurements. It is shown that the antenna is suitable for near field ground penetrating radar (GPR) applications.

关键词： Magnetoelectric effects Ultra wideband antennas

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