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A novel matrix topology-based analysis method of thermal circuits for reliability optimization of HSER

Chinese Journal of Aeronautics 2024年第4期37卷 479-492页

作者： Huimin LIANG Bo LI Jiaxin YOU Shan JIANG Mengtong ZHU Aobo WANG Department of Electrical Engineering Harbin Institute of TechnologyHarbin 150001China Nanjing Research Institute of Electronics Technology Nanjing 210008China

Hermetically Sealed Electromagnetic Relay(HSER), used in aviation and aerospace,demands high reliability due to its critical applications. Given its complex operating conditions, efficient thermal analysis is essential for optimizing reliability. The commonly used Finite Element Method(FEM) is often time-consuming and may not be efficient or adaptable for complex multi-dimensional system calculations and design processes. This paper introduces an analysis method for thermal networks based on matrix perspective technology, encompassing matrix transformation, backpropagation of the heat path model, temperature rise calculation, solution comparison, and product implementation. Using the similarity theory of heat circuits, a basic thermal unit is established. Based on the fundamental connection between key components, a thermal network for a typical HSER is designed. An experimental system is set up, and the thermal network model's accuracy is confirmed using test data. Employing the topology analysis method, the topology of the thermal network is analyzed under both coil-energized and de-energized states. Potential thermal paths are identified, leading to optimized solutions for the HSER. Utilizing these solutions, the thermal path matrix topology model is backpropagated to the thermal path for temperature rise calculations. When compared to prototype HSER test data, the efficiency and accuracy of this matrix topology-based analysis method are confirmed.

关键词： Thermal networks HSER(Hermetically Sealed Electromagnetic Relay) Heat-circuit topology model Heat-circuit matrix Optimization design

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Multi-UAVs Collaborative Path Planning in the Cramped Environment

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IEEE/CAA Journal of Automatica Sinica 2024年第2期11卷 529-538页

作者： Siyuan Feng Linzhi Zeng Jining Liu Yi Yang Wenjie Song School of Automation Beijing Institute of TechnologyNanjing 210039China Nanjing Research Institute of Electronics Technology Nanjing 210039China Yichang Testing Technique research institute Yichang 443003China IEEE

Due to its flexibility and complementarity, the multiUAVs system is well adapted to complex and cramped workspaces, with great application potential in the search and rescue(SAR) and indoor goods delivery fields. However, safe and effective path planning of multiple unmanned aerial vehicles(UAVs)in the cramped environment is always challenging: conflicts with each other are frequent because of high-density flight paths, collision probability increases because of space constraints, and the search space increases significantly, including time scale, 3D scale and model scale. Thus, this paper proposes a hierarchical collaborative planning framework with a conflict avoidance module at the high level and a path generation module at the low level. The enhanced conflict-base search(ECBS) in our framework is improved to handle the conflicts in the global path planning and avoid the occurrence of local deadlock. And both the collision and kinematic models of UAVs are considered to improve path smoothness and flight safety. Moreover, we specifically designed and published the cramped environment test set containing various unique obstacles to evaluating our framework performance thoroughly. Experiments are carried out relying on Rviz, with multiple flight missions: random, opposite, and staggered, which showed that the proposed method can generate smooth cooperative paths without conflict for at least 60 UAVs in a few minutes.The benchmark and source code are released in https://***/inin-xingtian/multi-UAVs-path-planner.

关键词： Collision avoidance conflict resolution multi-unmanned aerial vehicles(UAVs)system path planning

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A 14b 250MSps Pipelined ADC with Digital Self-calibration in 0.18μm CMOS Process

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Chinese Journal of electronics 2018年第3期27卷 535-539页

作者： LIU Haitao WU Junjie ZHANG Lizheng DENG Qing SUN Jie Nanjing Research Institute of Electronics Technology

A 14-bit pipelined Analog-to-digital converter(ADC) with a single-side digital self-calibration in a 0.18μm CMOS process is presented. The single-side foreground digital self-calibration is introduced to reduce the nonlinearity caused by capacitor mismatches. The ADC has a front-end Sample-and-hold(SH) circuit, followed by 13 1.5 bit/stage sub-ADC and 2 bit flash ADC at last. Test results show that, with a 140 MHz input and 200 MHz sampling rate, the SIAND is improved from 59 dB to 66 dB and SFDR is improved from 62 dBc to 82 dBc with the digital calibration. The measured SFDR reaches 77 dBc even at 250 MSps after calibration. The total power dissipation is 398 mW at 250 MSps including the parallel Low voltage differential signal(LVDS) output drivers.

关键词： Pipelined Analog-to-digital converter(ADC) Capacitor mismatch Digital self-calibration

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Modified OMP method for multi-target parameter estimation in frequency-agile distributed MIMO radar

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Journal of Systems Engineering and electronics 2022年第5期33卷 1089-1094页

作者： XING Wenge ZHOU Chuanrui WANG Chunlei College of Information Science and Engineering Southeast UniversityNanjing 211189China Nanjing Research Institute of Electronics Technology Nanjing 210039China

Introducing frequency agility into a distributed multipleinput multiple-output(MIMO)radar can significantly enhance its anti-jamming ability.However,it would cause the sidelobe pedestal problem in multi-target parameter estimation.Sparse recovery is an effective way to address this problem,but it cannot be directly utilized for multi-target parameter estimation in frequency-agile distributed MIMO radars due to spatial diversity.In this paper,we propose an algorithm for multi-target parameter estimation according to the signal model of frequency-agile distributed MIMO radars,by modifying the orthogonal matching pursuit(OMP)algorithm.The effectiveness of the proposed method is then verified by simulation results.

关键词： distributed multiple-input multiple-output(MIMO)radar multi-target parameter estimation frequency agility modified orthogonal matching pursuit(OMP)method

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Gaussian mixture model based adaptive control for uncertain nonlinear systems with complex state constraints

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Chinese Journal of Aeronautics 2022年第5期35卷 361-373页

作者： Yuzhu BAI Rong CHEN Yong ZHAO Yi WANG College of Aerospace and Engineering National University of Defense TechnologyChangsha 410073China Nanjing Research Institute of Electronics Technology Nanjing 210000China

This paper addresses an uncertain nonlinear control system problem with complex state constraints and mismatched uncertainties.A novel Gaussian Mixture Model(GMM)based adaptive PID-Nonsingular Terminal Sliding Mode Control(NTSMC)(GMM-adaptive-PID-NTSMC)method is proposed.It is achieved by combining a GMM based adaptive potential function with a novel switching surface of PID-NTSMC.Next,the stability of the closed-loop system is proved.The main contribution of this paper is that the GMM method is applied to obtain the analytic description of the complex bounded state constraints,ensuring that the states'constraints are not violated with GMM-based adaptive potential function.The developed potential function can consider the influence of uncertainties.More importantly,the GMM-adaptive-PID-NTSMC can be generalized to control a more representative class of uncertain nonlinear systems with constrained states and mismatched uncertainties.In addition,the proposed controller enhances the robustness,and requires less control cost and reduces the steady state error with respect to the Artificial Potential Function based Nonsingular Terminal Sliding Mode Control(APF-NTSMC),GMM-NTSMC and GMM-adaptive-NTSMC.At last,numerical simulation is performed to validate the superior performance of the proposed controller.

关键词： Gaussian mixture model Nonlinear systems State constrained Terminal sliding mode control Uncertain

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Improved TQWT for marine moving target detection

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Journal of Systems Engineering and electronics 2020年第3期31卷 470-481页

作者： PAN Meiyan SUN Jun YANG Yuhao LI Dasheng XIE Sudao WANG Shengli CHEN Jianjun Nanjing Research Institute of Electronics Technology Nanjing 210039China Key Laboratory of IntelliSense technology China Electronics Technology Group CorporationNanjing 210039China

Under the conditions of strong sea clutter and complex moving targets,it is extremely difficult to detect moving targets in the maritime surface.This paper proposes a new algorithm named improved tunable Q-factor wavelet transform(TQWT)for moving target detection.Firstly,this paper establishes a moving target model and sparsely compensates the Doppler migration of the moving target in the fractional Fourier transform(FRFT)domain.Then,TQWT is adopted to decompose the signal based on the discrimination between the sea clutter and the target’s oscillation characteristics,using the basis pursuit denoising(BPDN)algorithm to get the wavelet coefficients.Furthermore,an energy selection method based on the optimal distribution of sub-bands energy is proposed to sparse the coefficients and reconstruct the target.Finally,experiments on the Council for Scientific and Industrial research(CSIR)dataset indicate the performance of the proposed method and provide the basis for subsequent target detection.

关键词： marine moving target detection improved tunable Q-factor wavelet transform(TQWT) fractional Fourier transform(FRFT) basis pursuit denoising(BPDN)

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A novel target detection approach based on adaptive radar waveform design

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Chinese Journal of Aeronautics 2013年第1期26卷 194-200页

作者： Wang Haitao Shi Lei Wang Youlin Ben De Nanjing Research Institute of Electronics Technology

To resolve problems of complicated clutter, fast-varying scenes, and low signal-clutterratio （SCR） in application of target detection on sea for space-based radar （SBR）, a target detection approach based on adaptive waveform design is proposed in this paper. Firstly, complicated sea clutter is modeled as compound Gaussian process, and a target is modeled as some scatterers with Gaussian reflectivity. Secondly, every dwell duration of radar is divided into several sub-dwells. Regular linear frequency modulated pulses are transmitted at Sub-dwell 1, and the received signal at this sub-dwell is used to estimate clutter covariance matrices and pre-detection. Estimated matrices are updated at every following sub-dwell by multiple particle filtering to cope with fast-varying clutter scenes of SBR. Furthermore, waveform of every following sub-dwell is designed adaptively according to mean square optimization technique. Finally, principal component analysis and generalized likelihood ratio test is used for mitigation of colored interference and property of constant false alarm rate, respectively. Simulation results show that, considering configuration of SBR and condition of complicated clutter, 9 dB is reduced for SCR which reliable detection requires by this target detection approach. Therefore, the work in this paper can markedly improve radar detection performance for weak targets.

关键词： Adaptive waveform design Generalized likelihood ratio test Multiple particle filter Principal component analysis Radar systems Space-based radar

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A fractional-N frequency divider for multi-standard wireless transceiver fabricated in 0.18μm CMOS process

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Journal of Semiconductors 2017年第12期38卷 73-80页

作者： Jiafeng Wangt Xiangning Fan Xiaoyang Shi Zhigong Wang Nanjing Research Institute of Electronics Technology Nanjing 210000China

With the rapid evolution of wireless communication technology, integrating various communication modes in a mobile terminal has become the popular trend. Because of this, multi-standard wireless technology is one of the hot spots in current research. This paper presents a wideband fractional-N frequency divider of the multi-standard wireless transceiver for many applications. High-speed divider-by-2 with traditional source- coupled-logic is designed for very wide band usage. Phase switching technique and a chain of divider-by-2/3 are applied to the programmable frequency divider with 0.5 step. The phase noise of the whole frequency synthesizer will be decreased by the narrower step of programmable frequency divider. A-E modulator is achieved by an improved MASH 1-1-1 structure. This structure has excellent performance in many ways, such as noise, spur and input dynamic range. Fabricated in TSMC 0.18/tin CMOS process, the fractional-N frequency divider occupies a chip area of 1130 × 510μm^2 and it can correctly divide within the frequency range of 0.8-9 GHz. With 1.8 V supply voltage, its division ratio ranges from 62.5 to 254 and the total current consumption is 29 mA.

关键词： multi-standard frequency synthesizer fractional-N frequency divider phase switching △-∑ modulat-or

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An interference suppression algorithm for cognitive bistatic airborne radars

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Journal of Systems Engineering and electronics 2022年第3期33卷 585-593页

作者： XIA Deping ZHANG Liang WU Tao HU Wenjun National Laboratory of Radar Signal Processing Xidian UniversityXi’an 710071China Nanjing Research Institute of Electronics Technology Nanjing 210039China

Interference suppression is a challenge for radar researchers, especially when mainlobe and sidelobe interference coexist. We present a comprehensive anti-interference approach based on a cognitive bistatic airborne radar. The risk of interception is reduced by lowering the launch energy of the radar transmitting terminal in the direction of interference;main lobe and sidelobe interferences are suppressed via cooperation between the two radars. The interference received by a single radar is extracted from the overall radar signal using multiple signal classification(MUSIC), and the interference is cross-located using two different azimuthal angles. Neural networks allowing good, non-linear nonparametric approximations are used to predict the location of interference, and this information is then used to preset the transmitting notch antenna to reduce the likelihood of interception. To simultaneously suppress mainlobe and sidelobe interferences, a blocking matrix is used to mask mainlobe interference based on azimuthal information, and an adaptive process is used to suppress sidelobe interference. Mainlobe interference is eliminated using the data received by the two radars. Simulation verifies the performance of the model.

关键词： interference suppression cognitive bistatic airborne radar neural network blocking matrix

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Study on welding process performance of HG70D high strength steel plate

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China Welding 2018年第3期27卷 59-64页

作者：杨林蒋晓虎王孝虎 Nanjing Research Institute of Electronics Technology Nanjing 210039 China

In this paper, the performance of HG70D welded joint of ultra-high strength steel plates is presented, and the performance of HG70D and Q345B welded joints is studied. The high strength steel plate HG70D showed excellent weldability. Through the X-ray inspection of welded joints, tensile strength, impact test and bending performance test, the comprehensive performance of the joint was excellent. The macroscopic and microscopic metallographic analysises of the welded joints show that the welding seams included pearlite, sorbite, ferrite, etc. The influence of stress annealing temperature on HG70D of high strength steel plate was analyzed by heat treatment.

关键词： ultra-high strength steel HG70D welding metallographic

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