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Fault-tolerant FADS system development for a hypersonic vehicle via neural network algorithms

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Theoretical & Applied Mechanics Letters 2023年第5期13卷 357-366页

作者： Qian Wan Minjie Zhang Guang Zuo Tianbo Xie LandSpace Technology corporation Ltd.H1 Zhonghang Intl Plaza 13 Ronghua South RoadBeijing 100176China Department of aerospace and Mechanical Engineering University of Southern CaliforniaLos AngelesCA 90089-1189USA

Hypersonic vehicles suffer from extreme aerodynamic heating during flights, especially around the area of leading edge due to its small curvature. Therefore, flush air data sensing(FADS) system has been developed to perform accurate measurement of the air data parameters. In the present study, the method to develop the FADS algorithms with fail-operational capability for a sharp-nosed hypersonic vehicle is provided. To be specific, the FADS system implemented with 16 airframe-integrated pressure ports is used as a case study. Numerical simulations of different freestream conditions have been conducted to generate the database for the FADS targeting in 2 ≤ Ma ≤ 5 and 0 km ≤ H ≤ 30 km. Four groups of neural network algorithms have been developed based on four different pressure port configurations, and the accuracy has been validated by 280 groups of simulations. Particularly, the algorithms based on the 16-port configuration show an excellent ability to serve as the main solver of the FADS, where 99. 5% of the angle-of-attack estimations are within the error band ±0. 2°. The accuracy of the algorithms is discussed in terms of port configuration. Furthermore, diagnosis of the system health is present in the paper. A fault-tolerant FADS system architecture has been designed, which is capable of continuously sensing the air data in the case that multi-port failure occurs, with a reduction in the system accuracy.

关键词： FADS System Hypersonic vehicle Neural network Numerical simulation Fault detection Redundancy management

Analysis on Some of Software Reliability Models

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Journal of Systems Engineering and Electronics 2001年第1期12卷 88-96页

作者： Song Xiaoqiu Software Evaluation and Test Center of China aerospace corporation, Beijing 100854, P. R. China Software Evaluation and Test Center of China aerospace corporation Beijing 100854 P. R. China

Software reliability and maintainability evaluation tool (SRMET 3.0) is introducted in detail in this paper, which was developed by Software Evaluation and Test Center of China aerospace Mechanical corporation. SRMET 3.0 is supported by seven software reliability models and four software maintainability models. Numerical characteristics for all those models are deeply studied in this paper, and corresponding numerical algorithms for each model are also given in the paper.

关键词： Software Reliability Evaluation Model

Boost-Phase ballistic missile trajectory estimation with ground based radar

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Journal of Systems Engineering and Electronics 2006年第4期17卷 705-708页

作者： Tang Yuyan Huang Peikang The Second Academy of China aerospace Science & Industry corporation Beijing 100854 P.R.China

A conditional boost-phase trajectory estimation method based on ballistic missile （BM） information database and classification is developed to estimate and predict boos-phase BM trajectory. The main uncertain factors to describe BM dynamics equation are reduced to the control law of trajectory pitch angle in boost-phase. After the BM mass at the beginning of estimation, the BM attack angle and the modification of engine thrust denoting BM acceleration are modeled reasonably, the boost-phase BM trajectory estimation with ground based radar is well realized. The validity of this estimation method is testified by computer simulation with a typical example.

关键词： trajectory estimation boost-phase ground based radar ballistic missile.

Tracking algorithm of BPSK signal in low bit SNR and high dynamic scenarios

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Journal of Beijing Institute of Technology 2015年第1期24卷 118-127页

作者：王鹏陈国瑛 Beijing Institute of Electronic System Engineering the Second Academy of China aerospace Science and Industry corporation

A new tracking algorithm is proposed aiming at the tracking problem in low bit signal-to- noise ratio （i. e. , Eb/N0 ） scenarios, in which the bit clock regenerated by bit synchronization loop decides loop update moment. The double frequency processing and non-coherent accumulation tech- nologies are applied to eliminate the impact of data polarity inversion, and then long time accumula- tion improves the input signal-to-noise ratio of discriminator. The frequency locked loop and phase locked loop constitute a carrier loop in parallel, which can meet the high dynamic demands. The ef- fectiveness of this algorithm has been corroborated by theoretical analysis, simulation and measure- ments, and the new tracking algorithm has been used in an aerospace engineering project successfully.

关键词： tracking double frequency processing non-coherent low bit signal-to-noise ratio

Minimum-fuel orbit transfer between SSO using low-thrust considering J2 perturbation

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Journal of Beijing Institute of Technology 2016年第S2期25卷 10-14页

作者：赵书阁李延艳张景瑞向开恒 The Second System Design Department of the Second Research Academy of China aerospace Science and Industry corporation School of aerospace Engineering Beijing Institute of Technology

The objective of this paper is to find the minimum-fuel orbit transfer between sun-synchronous orbits with low-thrust while considering the Jperturbation.A quasi-circular orbit model with the effect of the Jperturbation is *** minimum fuel problem is solved by the indirect optimization *** effective techniques are employed in solving the indirect optimization problem with a shooting method,which include energy-to-fuel homotopy,normalization of the initial costate vector,computation of the analytic Jacobians matrix,and switching *** simulation results show that the solution of the minimum-fuel long duration orbit transfer with lowthrust considering Jperturbation can be obtained by applying these preceding techniques.

关键词： minimum fuel J2 perturbation sun-synchronous orbits active debris removal

A 2-step GPS carrier tracking loop for urban vehicle applications

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Journal of Systems Engineering and Electronics 2017年第5期28卷 817-826页

作者： Hongyang Zhang Luping Xu Yue Jian Xiaochen Ma School of aerospace Science and Technology Xidian University Xi'an Flight Automatic Control Research Institute Aviation Industry Corporation of China Xi'an Aeronautics Computing Technique Research Institute Aviation Industry Corporation of China

Global positioning system (GPS) for vehicle applications in the urban area is challenged by low signal intensity. The carrier loop based on fast Fourier transform (FFT) can obtain a high signal to noise ratio (SNR) gain by increasing the observation time. However, this leads to a major problem that the acceleration cannot be ignored. The performance of the FFT-based loop will decline with the acceleration increasing. This paper discusses the effect of the dynamic on FFT first. Then a high performance carrier tracking loop for weak GPS L5 signals is proposed. It combines discrete chirp-Fourier transform (DCFT) and the phase fitting method to estimate Doppler frequency and Doppler rate simultaneously. First, a sequence of integration results is used to perform DCFT to estimate coarse Doppler frequency and Doppler rate. Second, the phase of the sequence is calculated and used to perform linear fitting. By the phase fitting method, the fine Doppler frequency and Doppler rate can be estimated. The computation cost is small because the integration results are used and the phase fitting method needs only coarse estimates of Doppler frequency and Doppler rate. Compared with FFT and DCFT, the precision of the phase fitting method is not limited by the resolution. Thus the proposed loop can get high precision and low carrier to noise ratio (C/N-0) tracking threshold. Simulation results show this loop has a great improvement than conventional loops for urban weak-signal applications.

关键词： satellite navigation receiver signal processing frequency lock loop

Study on dispersion characteristics of terahertz waves in helical waveguides

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Chinese Physics B 2020年第11期29卷 386-390页

作者：孙金海张少华张旭涛蔡禾刘永强巢增明 Science and Technology on Electromagnetic Scattering Laboratory Beijing 100854China China aerospace System Engineering corporation Beijing 100070China

Corresponding to the atmospheric transmission windows of the electromagnetic spectrum in the low terahertz range,the mode coupling and dispersion characteristics of two helically corrugated waveguides(HCW)in the frequency ranges of 90 GHz-100 GHz and 260 GHz-265 GHz are *** analytic calculations and numerical simulations,dispersion curves and structural parameters of the two frequency ranges waveguides are obtained.A novel method was proposed to obtain the dispersion of the HCW from the eigenwave solution using a periodic boundary *** HCW in a frequency range of 90 GHz-100 GHz was fabricated and its dispersion performance was *** comparing the measured results with the theoretical and the simulated results,the validity of the analytical and simulation method is *** to our machining capability,the dispersion of the 260 GHz-265 GHz HCW was only simulated and calculated and it was found that the results agree well with each other.

关键词： coupling coefficient dispersion curves gyrotron traveling wave tube(gyro-TWT) helical waveguide

Sequential quadratic programming-based non-cooperative target distributed hybrid processing optimization method

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Journal of Systems Engineering and Electronics 2023年第1期34卷 129-140页

作者： SONG Xiaocheng WANG Jiangtao WANG Jun SUN Liang FENG Yanghe LI Zhi Beijing Institute of Electronic Engineering China Aerospace Science and Industry Corporation LimitedBeijing 100039China School of Intelligence Science and Technology University of Science and Technology BeijingBeijing 100083China Institute of Artificial Intelligence University of Science and Technology BeijingBeijing 100083China School of Systems Engineering National University of Defense TechnologyChangsha 410073China

The distributed hybrid processing optimization problem of non-cooperative targets is an important research direction for future networked air-defense and anti-missile firepower systems. In this paper, the air-defense anti-missile targets defense problem is abstracted as a nonconvex constrained combinatorial optimization problem with the optimization objective of maximizing the degree of contribution of the processing scheme to non-cooperative targets, and the constraints mainly consider geographical conditions and anti-missile equipment resources. The grid discretization concept is used to partition the defense area into network nodes, and the overall defense strategy scheme is described as a nonlinear programming problem to solve the minimum defense cost within the maximum defense capability of the defense system network. In the solution of the minimum defense cost problem, the processing scheme, equipment coverage capability, constraints and node cost requirements are characterized, then a nonlinear mathematical model of the non-cooperative target distributed hybrid processing optimization problem is established, and a local optimal solution based on the sequential quadratic programming algorithm is constructed, and the optimal firepower processing scheme is given by using the sequential quadratic programming method containing non-convex quadratic equations and inequality constraints. Finally, the effectiveness of the proposed method is verified by simulation examples.

关键词： non-cooperative target distributed hybrid processing multiple constraint minimum defense cost sequential quadratic programming

Energy saving design of the machining unit of hobbing machine tool with integrated optimization

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Frontiers of Mechanical Engineering 2022年第3期17卷 209-227页

作者： Yan LV Congbo LI Jixiang HE Wei LI Xinyu LI Juan LI State Key Laboratory of Mechanical Transmission College of Mechanical and Vehicle EngineeringChongqing UniversityChongqing400044China Department of Process Technology Sichuan Aerospace Fenghuo Servo Control Technology CorporationChengdu611130China State Key Laboratory of Digital Manufacturing Equipment and Technology Huazhong University of Science and TechnologyWuhan430074China

The machining unit of hobbing machine tool accounts for a large portion of the energy consumption during the operating *** optimization design is a practical means of energy saving and can reduce energy consumption ***,this issue has rarely been discussed in depth in previous research.A comprehensive function of energy consumption of the machining unit is built to address this *** models are established by using effective fitting *** integrated optimization model for reducing tool displacement and energy consumption is developed on the basis of the energy consumption function and surrogate models,and the parameters of the motor and structure are considered *** show that the energy consumption and tool displacement of the machining unit are reduced,indicating that energy saving is achieved and the machining accuracy is *** influence of optimization variables on the objectives is analyzed to inform the design.

关键词： energy saving design energy consumption machining unit integrated optimization machine tool