He Zhang

DC splitting for transmitter power limit low pass channel information and power transfer

In this paper, we study a transmitter power limit low pass channel information and power transfer system for ammunition data link. A DC splitting architecture where a DC signal is used for power transfer and several OFDM subcarriers are used for information transfer is designed for the system. The DC and OFDM power allocation problem for maximizing the information transfer rate is proposed and constraints of power splitter leakage, DC/DC narrowband noises, transmitter available power, maximum receiver security and minimum receiver sustainable power are taken into account. Lagrange multiplier algorithm is used for solving the constrained convex optimization problem. Simulation result shows that the optimal power allocation can be gotten under the proposed design. The sub-bound of the transmitter available power and the up-bound of active bandwidth of the proposed architecture are calculated by using the algorithm.

Theoretical Study on the Influence of Transmission Parameters on the Transmission Performance of Magnetic Resonance Wireless Power Transmission Systems

Magnetic resonance wireless power transmission technology is based on the phenomenon of resonant coupling to realize non-contact power transmission via near magnetic field. Based on the mutual coupling model of resonance system, the influence laws of system transmission parameters, such as coil coupling coefficients, load resistance, etc., on the transmission performance are theoretically studied in this paper. The research results shows that the power high-efficiency and high-quality transmission does not depend on the large coil loop coupling coefficient and the working frequencies of maximum power and maximum efficiency transmission do not coincide at most condition. Transmission systems with a high resonance frequency can produce high power and efficiency transmission over short distances. In addition, by increasing the coil diameter or wire diameter can improve the system quality factor, and optimize the energy transmission performance.

System for Measuring the Burst Point Time Base on APD

Aiming at the burst point time measuring device cannot timely show the burst point time measurement situation, a new measuring system was designed. The pulse signal when the ammo was outing of the muzzle and exploding was detected by APD, the light pulse was converted to voltage pulse through an amplifying circuit. The timing display module was designed, the timing circuit got the voltage pulse and timing, and then the burst point time would show on LCD. All the photoelectric detector module was fixed with the special mechanical properties. The system could increase the maximum detection distance effectively, improve its detecting precision, and display the burst point time immediately. With the simulation experiment, the system had no failing to get the burst point time, and owned a stable performance. This design can provide a reference for the optimization and improvement of the burst point time measuring device.

Study of Receive Focusing Aspheric Optical Lens of Laser Fuze

This paper according to the problems of weak echo signal in the optical system of laser fuze. By analyzing the factors of measuring distance, combined with the specific requirements of laser fuze, according to aspheric optical design theory, using Optical Software of ZEMAX. Design single receive focusing lens of laser fuze. Simulation results show that the echo signal can be efficiently brought together. Finally, according to the design, non-spherical lens is processed. The experimental results show it has a clear echo signal when detection range is 18m.

Comparison of Two Two-Equation Turbulence Model Used for the Numerical Simulation of Underwater Ammunition Fuze Turbine Flow Field

To figure out the problem of turbulence simulation of underwater ammunition fuze turbine numerical simulation, respectively, realizable k-ε turbulence model and SST k-ω turbulence model are used for two-phase flow numerical simulation of the turbine rotation. The analysis compared the calculation results of the two turbulence models. The results showed that: the cavitation scale obtained from realizable k-ε turbulence model is shorter than that of SST k-ω turbulence model; turbine surface pressure distribution trends are similar of this two model, the results of realizable k-ε turbulence model are bigger than SST k-ω turbulence model; the turbine axial pressure coefficients using realizable k-ε turbulence model are also bigger than that of SST k-ω turbulence model, and the deviation increases with the speed increase.

Analysis and Design of the Reliability of a Wire Setting System

Reliability as an important index occupies an important position in electronic time fuze design. Small and medium caliber ammunition could be set in wire form or wireless form. Wireless setting can be divided into several forms, electromagnetism induction setting, radio frequency setting, laser setting and so on. There are many existing disadvantages in this technique, such as weak EMI ability, complex structure and poor reliability, while wire setting has the advantages opposite them. A wire setting system for electronic time fuse was designed in this article. In allusion to the problems of low ammunition reliability in the experiment, a method that could detect the working condition of the fuze effectively is presented, and bring a great help for finding out the root of the poor reliability. The experimental results showed that the effective rate of the improved electronic time fuze reached 100% and timing accuracy reached +-3 ms. This study provides a reference for the design of the reliability of setting system.

The Research of Wireless Low Power Transmission System Based on Magnetic Resonant Coupling

In order to study on the relationship between transmission parameters and transmission performance of wireless power transmission system based on the basic principles of magnetic resonant coupling, because of magnetic induction coupling with low-efficiency and short-distance, the basic circuit model of wireless power transmission system via Strongly Coupled Magnetic Resonances was analyzed. The expression of the parameters such as relationships between efficiency, frequency and distance was derived. Further more, the experiment of wireless power transmission system was designed based on the results of the analysis. At last, the results of experiment show that the theoretical derivation is correct and all the system is affected by the transmission parameters.

Analysis of Wireless Energy Transfer System Using Magnetic Resonant Coupling

In order to research the relationship between coupling distance and transmission efficiency, study on the transmission characteristics of magnetic resonant coupling for wireless power transmission system, simulation model of wireless power transmission system via magnetic resonance coupling were established based on the theory of two ports network analysis method. The frequency expression of maximum efficiency and the resonant frequency splitting phenomenon condition of a contact-less power transmission system were derived. In a weak coupling at resonance, magnetic resonant coupling can transfer energy with high efficiency. The resonant frequency changes from two to one depending on the critical condition. Until a certain distance, maximum efficiencies are not got. The transmission characteristics of this system were researched by simulation software and experiments. The results show that the transmission characteristics are consistent with theoretical analysis and simulation.

Inverse Attitude Solution Model and Numerical Simulation of a 2-DOF Stabilized Platform

Considering the attitude stabilization requirements for an unmanned marine platform equipped with electro-optic detection equipment, a stabilized platform based on a 2-DOF parallel mechanism has been designed. The stabilized platform, especially for the requirements of small space and high load inertia, has such transmission branch chain with fixed ball-screw. The structure, DOF and kinematics of the platform has been analyzed, besides, the mathematical model of the platforms attitude inverse solution has been established. Numerical simulation for the derivate mathematical model and ADAMS simulation analysis has been done. In order to verify the correctness of the mathematical model, the motion process of the load-platform is described by a time function. The time function of the drive components calculated from the above two ways is used for the comparison of numerical simulation and ADAMS simulation. The results prove that the mathematical model established in this paper and ADAMS simulation results coincide.

Photodetection Technology Based on Laser Coding Emission

For the extremely weak echo signal and the poor anti-interference ability of the long-distance laser fuze, the high signal noise ratio (SNR) receiving system based on laser coding mode was designed. In order to improve the weak signal receiving ability, the avalanche photodiode (APD) with high sensitivity, low noise and high gain was adopted. And the optimum multiplication factor of APD when the system obtains the highest SNR was analyzed and calculated. Then, the amplifying circuit optimum matching with APD and the decoding circuit were designed, and validated by the experiments. The theory and experiment results indicate that the design is efficiency and capable to the long distance laser fuze, the system can exactly decode the weak laser coding signals received and export the ignition signal.