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Defence Technology（防务技术） 2024年第2期32卷 412-429页

作者： Wenxue Chen yudong hu Changsheng Gao Ruoming An School of Astronautics Harbin Institute of TechnologyHarbin 150001China

This paper investigates interception missiles’trajectory tracking guidance problem under wind field and external disturbances in the boost ***,the velocity control in such trajectory tracking guidance systems of missiles is *** our contribution,the velocity control channel is designed to deal with the intractable velocity problem and improve tracking *** global prescribed performance function,which guarantees the tracking error within the set range and the global convergence of the tracking guidance system,is first proposed based on the traditional ***,a tracking guidance strategy is derived using the integral sliding mode control techniques to make the sliding manifold and tracking errors converge to zero and avoid ***,an improved switching control law is introduced into the designed tracking guidance algorithm to deal with the chattering problem.A back propagation neural network(BPNN)extended state observer(BPNNESO)is employed in the inner loop to identify *** obtained results indicate that the proposed tracking guidance approach achieves the trajectory tracking guidance objective without and with disturbances and outperforms the existing tracking guidance schemes with the lowest tracking errors,convergence times,and overshoots.

关键词： BP network neural Integral sliding mode control(ISMC) Missile defense Prescribed performance function(PPF) State observer Tracking guidance system

Parametric modeling of hypersonic ballistic data based on time varying auto-regressive model

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Science China(Technological Sciences) 2020年第8期63卷 1396-1405页

作者： hu yudong LI JunLong ZHANG Zhao JING WuXing GAO ChangSheng Department of Aerospace Engineering Harbin Institute of TechnologyHarbin 150001China China Aerospace Science and Industry Corporation Beijing 100854China

For describing target motion in hypersonic vehicle defense,a parametric analyzing and modeling method on ballistic data is proposed based on time varying auto-regressive *** data are regarded as non-stationary random signal,where the hidden internal law is ***,ballistic data are decomposed into smooth linear trend signal and non-stationary periodic skip signal with ensemble empirical mode decomposition method to avoid mutual interference between different modal ***,the linear trend signal and the periodic skip signal are modeled *** linear trend signal is approximated by power function regressive estimator and the periodic skip signal is modeled based on time varying auto-regressive *** order to determine optimal model orders,a novel method is presented based on information theoretic criteria and the criteria of minimizing the mean absolute ***,the consistency test is conducted by investigating the time-frequency spectrum characteristics and statistical properties of outputs of the parametric model established above and dynamics model under the same initial *** results demonstrate that the parametric model established by the proposed method shares a high consistency with the original dynamics model.

关键词： hypersonic vehicle parametric modeling ballistic data decomposition time varying auto-regressive periods drift

A novel adaptive lateral reentry guidance algorithm with complex distributed no-fly zones constraints

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Chinese Journal of Aeronautics 2022年第7期35卷 128-143页

作者： yudong hu Changsheng GAO Junlong LI Wuxing JING Wenxue CHEN School of Astronautics Harbin Institute of TechnologyHarbin 150001China Beijing Institute of Electronic System Engineering China Aerospace Science and Industry CorporationBeijing 100854China

Aimed at complex distributed no-fly zones avoidance problems,a novel adaptive lateral reentry guidance algorithm is ***,by introducing the improved attractive and repulsive potential fields,an improved artificial potential field method is *** with the proposed judgment criterion for whether a no-fly zone has been avoided,the proposed improved artificial potential field method effectively solves the reference heading angle determination problem under the constraints of complex distributed no-fly ***,based on the proposed no-fly zone’s threat quantitative evaluation method and the reference heading angle determined by the proposed improved artificial potential field method,the heading corridor is improved to increase its sensitivity to the threat changes of the no-fly ***,for satisfying the requirements of complex distributed no-fly zones avoidance,a novel guidance logic via improved heading corridor is proposed to update the reference heading corridor adaptively in real time according to the threat and constraint changes of the no-fly zones,and the bank reversal logic is employed to control the lateral *** simulation results for nominal and dispersed cases indicate that the proposed guidance algorithm has high robustness,stability,and applicability,and is feasible and effective to deal with the complex distributed no-fly zones avoidance problems.

关键词： Guidance strategy Heading corridor Hypersonic vehicles Improved artificial potential field Lateral reentry guidance Threat quantitative evaluation

Dual-wavelength flash Raman mapping method for measuring thermal diffusivity of the suspended nanowire

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Science China(Technological Sciences) 2020年第5期63卷 748-754页

作者： hu yudong FAN AoRan WANG HaiDong MA WeiGang ZHANG Xing Key Laboratory for Thermal Science and Power Engineering of Ministry of Education Department of Engineering MechanicsTsinghua UniversityBeijing 100084China

In this paper,we present a dual-wavelength flash Raman(DFR)mapping method for measuring the thermal diffusivity of a suspended nanowire.A heating pulse is used to heat the nanowire sample,and a probing pulse of different wavelength is used to measure the increase in *** laser absorption coefficient can be eliminated by normalization,and the thermal diffusivity of the sample can be extracted from the normalized temperature *** infinite heat conduction model is used in this method to avoid the influence of boundary thermal *** changing the position of the probing laser center,the measurement sensitivity of thermal diffusivity can be further *** position of maximum sensitivity is influenced by the thermal diffusivity of the nanowire,width of the heating pulse,radius of the heating laser spot,and characteristic length of the *** comprehensively analyze the influences of the various parameters,obtain the best measurement conditions,and attain maximum sensitivity,we propose a dimensionless physical model to analyze the heat conduction of the suspended *** on the analysis of the best dimensionless parameters,the corresponding appropriate measurement conditions can be *** analysis shows that when the radius of the heating laser spot is 1%of the length of the nanowire,the sensitivity of the DFR mapping method can be more than four times that of the concentric DFR method for measuring the thermal diffusivity of the nanowire.

关键词： DFR mapping method thermal diffusivity nanowire dimensionless analysis

Dual-Wavelength Laser Flash Raman Spectroscopy Method for In-Situ Measurements of the Thermal Diffusivity: Principle and Experimental Verification

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Journal of Thermal Science 2019年第2期28卷 159-168页

作者： FAN Aoran hu yudong MA Weigang WANG Haidong ZHANG Xing Key Laboratory for Thermal Science and Power Engineering of Ministry of Education Department of Engineering Mechanics Tsinghua University

This paper presents an in-situ, non-contact, non-destructive "dual-wavelength laser flash Raman spectroscopy method" for measuring the thermal diffusivity. In this method, a heating pulse is used to heat the sample and another pulsed laser with a different wavelength and negligible heating effect is used as a probe to measure the sample temperature changes during the heating and cooling periods from the Raman peak shifts. The sample temperature rise and fall curves are measured by changing the delay between the heating pulse and the probing pulse with the thermal diffusivity then characterized by fitting the temperature curves. The time delay between the heating and probing pulses can be precisely controlled with a minimum step of 100 ps. Hence, the temperature variation can be scanned with an ultra-high temporal resolution of up to 100 ps, which significantly improves the measurement accuracy of transient thermal parameters. The measurement accuracy of this method has been verified using a bulk material model and experiments. The measured thermal diffusivity of a silicon sample has been obtained to be 8.8×10^(-5 )m^2/s with a 3% difference between the measured value and the average result for bulk silicon in the literature which verifies the reliability and accuracy of this method.

关键词： dual-wavelength laser flash Raman spectroscopy method thermal diffusivity Raman spectroscopy nanomaterials bulk materials

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基于虚拟车桥试验台的后桥疲劳寿命预估

同济大学学报（自然科学版） 2014年第8期42卷 1231-1237页

作者：胡毓冬周鋐徐刚同济大学新能源汽车工程中心上海201804 上海大众汽车有限公司上海201805 同济大学汽车学院上海201804

介绍建立车桥虚拟试验台系统的方法流程,给出虚拟试验台机械系统和液压系统的建立方法,通过编程实现了虚拟试验台的控制算法即频域迭代自学习控制算法.通过联合仿真实现虚拟试验台载荷施加,对某扭转梁式后桥进行虚拟试验.利用虚拟试验... 详细信息

介绍建立车桥虚拟试验台系统的方法流程,给出虚拟试验台机械系统和液压系统的建立方法,通过编程实现了虚拟试验台的控制算法即频域迭代自学习控制算法.通过联合仿真实现虚拟试验台载荷施加,对某扭转梁式后桥进行虚拟试验.利用虚拟试验所得的车桥边界条件,结合有限元分析方法对后桥疲劳寿命和损伤进行了预估,并与试验结果比较,结果表明两者具有较高的一致性.

关键词：虚拟试验台迭代控制算法联合仿真疲劳寿命

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整车道路模拟试验台的控制算法

同济大学学报（自然科学版） 2012年第8期40卷 1244-1248页

作者：胡毓冬周鋐徐刚同济大学汽车学院上海201804 同济大学新能源汽车工程中心上海201804

介绍多输入多输出系统时域波形再现(TWR)过程,给出基于频率响应函数(FRF)模型的系统辨识方法以及基于频域迭代自学习控制(ILC)算法的目标信号迭代具体流程.针对整车道路模拟试验台控制算法软件的开发,提出在迭代过程中对信号进行适当重... 详细信息

介绍多输入多输出系统时域波形再现(TWR)过程,给出基于频率响应函数(FRF)模型的系统辨识方法以及基于频域迭代自学习控制(ILC)算法的目标信号迭代具体流程.针对整车道路模拟试验台控制算法软件的开发,提出在迭代过程中对信号进行适当重叠分段的频域迭代自学习控制算法.通过现有的四通道整车道路模拟试验台,在真实环境中成功实现了对某样车各车轮轴头处垂向加速度的时域波形再现.结果表明,该算法精度较高,能够作为试验台的控制算法.

关键词：道路模拟时域波形再现(TWR) 迭代自学习控制(ILC) 系统辨识

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大质量比滚控式变质心飞行器动力学特性分析

宇航学报 2024年第2期45卷 250-261页

作者：孙佳慧胡玉东高长生荆武兴哈尔滨工业大学航天学院哈尔滨150001

针对大质量比滚控式变质心再入飞行器结构参数设计问题,建立了包含活动体偏转运动的完整飞行器姿态伺服动力学模型,进而对活动体参数设计对姿态动力学耦合特性的影响展开分析研究。首先根据Routh准则给出了飞行器的纵向静稳定区域,并讨... 详细信息

针对大质量比滚控式变质心再入飞行器结构参数设计问题,建立了包含活动体偏转运动的完整飞行器姿态伺服动力学模型,进而对活动体参数设计对姿态动力学耦合特性的影响展开分析研究。首先根据Routh准则给出了飞行器的纵向静稳定区域,并讨论了配平攻角与活动体配置参数间的关系。对飞行器系统的动力学耦合分析结果表明,活动体偏转在控制滚转姿态的同时会对偏航姿态产生影响,进而造成控制精度的下降,甚至导致不稳定的飞行状态。为了在飞行器结构参数的优化设计中提高飞行器的控制性能、最小化飞行器滚转机动对偏航通道的影响,采用多尺度法对活动体偏转与飞行器偏航姿态运动构成的耦合非线性动力学系统在不同构型参数下的稳态解析解进行幅频响应特性分析,并给出考虑滚转偏航耦合约束下的大质量比滚控式变质心飞行器构型设计方案。

关键词：变质心飞行器动力学耦合非线性振动结构参数设计

拉曼方法同时测量单根碳纤维热物性和对流传热系数

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化工学报 2014年第S1期65卷 251-257页

作者：胡玉东刘锦辉王海东张兴热科学与动力工程教育部重点实验室清华大学工程力学系北京100084

主要完善并利用新近提出的激光拉曼测试方法,在333.15K环境温度下测量了单根碳纤维的热导率(不考虑接触热阻),并与直流通电法测量结果进行比较,两者符合较好,验证了新提出的激光拉曼测量方法的可行性。同时激光拉曼方法还测量得到了接... 详细信息

主要完善并利用新近提出的激光拉曼测试方法,在333.15K环境温度下测量了单根碳纤维的热导率(不考虑接触热阻),并与直流通电法测量结果进行比较,两者符合较好,验证了新提出的激光拉曼测量方法的可行性。同时激光拉曼方法还测量得到了接触热阻、碳纤维的激光吸收率及与空气的对流传热系数,并处理得到考虑接触热阻后修正的碳纤维真实热导率。

关键词：微尺度碳纤维激光拉曼热传导热导率接触热阻对流

基于复杂度的双接触式气液两相流流型识别研究

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动力工程学报 2017年第3期37卷 218-223页

作者：方立军刘玉东胡月龙华北电力大学能源动力与机械工程学院河北保定071003 大唐环境产业集团股份有限公司北京100097

提出了一种图像灰度直方图统计特征与复杂度理论(近似熵、样本熵和Lempel-Ziv复杂度)相结合的双接触式气液两相流流型识别方法.该方法利用高速摄像仪获取双接触式吸收塔内两相流流动图像,经过图像处理后,选取图像灰度均值作为统计特征,... 详细信息

提出了一种图像灰度直方图统计特征与复杂度理论(近似熵、样本熵和Lempel-Ziv复杂度)相结合的双接触式气液两相流流型识别方法.该方法利用高速摄像仪获取双接触式吸收塔内两相流流动图像,经过图像处理后,选取图像灰度均值作为统计特征,进而组成4种典型流型的灰度均值时间序列,并用3种复杂度算法对其进行分析识别.结果表明:3种复杂度算法分析得到的结果一致,在4种流型中,复杂度由高到低依次为:扰动式流型、漩涡式流型、液柱式流型和类鼓泡式流型.

关键词：双接触流型识别图像处理复杂度