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

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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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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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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Real-time estimation of maneuvering orbit by compensative modeling of "current" acceleration 27

Real-time estimation of maneuvering orbit by compensative mo...

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27th Conference of Spacecraft TT and C technology

作者： Liu, Y. Cao, Jianfeng Liu, Lei Science and Technology on Aerospace Flight Dynamic Laboratory Beijing100094 China Beijing Aerospace Control Center Beijing100094 China

ISBN: (纸本)9783662446867

The unknown maneuver is a key restriction for the real-time spacecraft tracking. For the modeling residual by dynamic of orbits, a compensative modeling method is developed according to the idea of "current" statistic. Then an orbit filter is established based on the new model and the unscented filter. By utilizing a nonmean value and time correlated stochastic process for the maneuvering acceleration, the new model can achieve an online auto-adaptivity for orbit acceleration with different maneuvers mode. Therefore, it can obtain a continuous and accurately estimated orbit for orbit with unknown maneuver. Simulation results for space target with series of random pulsar and continuous maneuvers validated the feasibility and efficiency of the new tracking filter. © Tsinghua University Press, Beijing and Springer-Verlag Berlin Heidelberg 2015.

关键词： Orbits

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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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Earth polar motion parameters high accuracy differential prediction 27

Earth polar motion parameters high accuracy differential pre...

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27th Conference of Spacecraft TT and C technology

作者： Chen, Lue Tang, Geshi Hu, Songjie Chen, Ming Li, Yifei Wang, Mei Sun, Jing Shi, Ming Li, Li National Key Laboratory of Science and Technology on Aerospace Flight Dynamic Beijing100094 China Beijing Aerospace Control Center Beijing100094 China

ISBN: (纸本)9783662446867

This paper proposes a method of Earth polar motion parameters prediction by dual differential least-squares (LS) and autoregressive (AR) model. Firstly, polar motion parameters are processed by dual differential method, the stationarity of polar motion parameters is improved. Then, LS+AR method is utilized to analyze the dual differential polar motion parameters to obtain the preliminary prediction results. Finally, the preliminary prediction results are processed by inverse dual differential method to obtain high accuracy polar motion prediction results. The prediction results are compared with EOP prediction comparison campaign (EOP_PCC) results, it shows that the short-term polar motion parameters prediction error is at the same level of EOP_PCC. The one day prediction accuracy of PMX is at the level of 0.25 mas, PMY is 0.2 mas, they are better than EOP_PCC one day polar motion prediction accuracy. © Tsinghua University Press, Beijing and Springer-Verlag Berlin Heidelberg 2015.

关键词： Forecasting

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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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