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蝴蝶飞行机理及仿蝴蝶扑翼飞行器研究进展综述

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工程科学学报 2024年第9期46卷 1582-1593页

作者：张益鑫李少石王兴坚王少萍朱生华杨梦琦北京航空航天大学自动化科学与电气工程学院北京100191 北京航空航天大学宁波研究院宁波315800 天目山实验室杭州310023

仿生扑翼飞行器具有高机动性、高隐蔽性以及高效率等突出优势,在军事侦查、探险搜救等领域具有较好的应用前景,而其应用的基础是对生物飞行机理的深入探究.随着先进运动观测和实验技术的引入,对昆虫飞行行为的记录和分析更为便捷和准确... 详细信息

仿生扑翼飞行器具有高机动性、高隐蔽性以及高效率等突出优势,在军事侦查、探险搜救等领域具有较好的应用前景,而其应用的基础是对生物飞行机理的深入探究.随着先进运动观测和实验技术的引入,对昆虫飞行行为的记录和分析更为便捷和准确.研究表明常见的昆虫拍打频率较高,在25~400 Hz之间,而蝴蝶较为特殊,其扑打频率较低,大约为10 Hz,对于蝴蝶的许多独特的飞行技能尚缺少足够的认识.蝴蝶前翼和后翼的翼面积都较大,身体同侧的前后翼几乎为同步拍打,且扑打幅度较大,甚至接近180°.蝴蝶飞行中身体有较大幅度的上下和俯仰震荡,翼和身体运动高度耦合.即便如此,蝴蝶仍具有敏捷的飞行能力,可以达到点对点的飞行目标,甚至上千公里的长途迁徙,是优秀的仿生学研究对象.因此,蝴蝶启发的仿生扑翼飞行器也得到了全世界研究人员的关注.蝴蝶的飞行机制相对于其他昆虫更加特殊,飞行行为和气动特性更为复杂,这使得仿蝴蝶扑翼飞行器的研制更加困难.目前对于仿蝴蝶飞行器的研制大多数对蝴蝶翼–身耦合的机理进行了简化,很少能实现受控的稳定飞行.最后,本文梳理了真实蝴蝶的飞行行为特点和飞行机理,指出了仿蝴蝶扑翼飞行器研制的关键技术,总结了该类飞行器未来的发展方向和应用前景.

关键词：蝴蝶飞行机理仿生机器人扑翼飞行器气动特性翼–身耦合飞行控制

基于AVMD和排列熵的t分布邻域嵌入流形HHO-SVM模拟电路故障诊断方法

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电子测量与仪器学报 2024年第6期38卷 233-240页

作者：陈晓梅王行健蔡烨周博华北电力大学北京102208

随着信息大数据时代的到来,对于电子系统的依赖程度越来越高,因此模拟电路的故障诊断的准确度要求与日俱增。而模拟电路故障诊断困难,是电子系统诊断维修的瓶颈。本文提出基于自适应变分模态分解(AVMD)和排列熵(PE)的t分布邻域嵌入流形... 详细信息

随着信息大数据时代的到来,对于电子系统的依赖程度越来越高,因此模拟电路的故障诊断的准确度要求与日俱增。而模拟电路故障诊断困难,是电子系统诊断维修的瓶颈。本文提出基于自适应变分模态分解(AVMD)和排列熵(PE)的t分布邻域嵌入流形哈里斯鹰优化支持向量机(HHO-SVM)模拟电路故障诊断方法。首先,利用AVMD对待测电路的观测信号进行自适应变分模态分解,得到多组IMF信号,不仅可以克服噪声干扰,而且可以来自适应地确定分解模式的数量,进一步提升分解精度;再对IMF计算排列熵,以充分体现IMF不同时段局部特征,二者相结合构建故障特征向量。并在此基础上,采用t分布式随机邻域嵌入(t-SNE)实现特征空间的流形学习和降维,构建具有良好区分度且保留原来的局部结构特征的故障特征向量;最后依靠哈里斯鹰优化支持向量机(HHO-SVM),使其具有良好的分类准确度,从而最终完成电路故障诊断。通过仿真验证,结果显示,本文方法故障诊断正确率可达100%,效果良好。

关键词：自适应变分模态分解AVMD t分布邻域嵌入故障诊断哈里斯鹰优化支持向量机

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Adaptive Fuzzy Torque Control of Passive Torque Servo Systems Based on Small Gain Theorem and Input-to-state Stability

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Chinese Journal of Aeronautics 2012年第6期25卷 906-916页

作者： wang xingjian wang Shaoping ZHAO Pan School of Automation Science and Electrical Engineering Beihang University Beij ing 100191 China Science and Technology on Aircraft Control Laboratory Beihang University Beijing 100191 China

Passive torque servo system （PTSS） simulates aerodynamic load and exerts the load on actuation system, but PTSS endures position coupling disturbance from active motion of actuation system, and this inherent disturbance is called extra torque. The most important issue for PTSS controller design is how to eliminate the influence of extra torque. Using backstepping technique, adaptive fuzzy torque control （AFTC） algorithm is proposed for PTSS in this paper, which reflects the essential characteristics of PTSS and guarantees transient tracking performance as well as final tracking accuracy. Takagi-Sugeno （T-S） fuzzy logic system is utilized to compensate parametric uncertainties and unstructured uncertainties. The output velocity of actuator identified model is introduced into AFTC aiming to eliminate extra torque. The closed-loop stability is studied using small gain theorem and the control system is proved to be semiglobally uniformly ultimately bounded. The proposed AFTC algorithm is applied to an electric load simulator （ELS）, and the comparative experimental results indicate that AFTC controller is effective for PTSS.

关键词： flight simulation adaptive control fuzzy control passive torque servo system electric load simulator extra torque small gain theorem input-to-state stability

强制企业社会责任披露对同行企业价值的影响——基于股票市场反应的证据

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投资研究 2024年第3期43卷 20-42页

作者：刘晓明王行健曾剑宇中国人民大学财政金融学院首都经济贸易大学工商管理学院中国人民大学国际并购与投资研究所工银瑞信基金管理有限公司

利用2008年上交所与深交所强制要求部分企业披露企业社会责任(CSR)这一准自然实验,以相同分析师数量作为同行企业判定标准,从同行企业的视角研究强制CSR披露对企业价值的影响。研究发现:第一,强制CSR披露政策使得披露企业的同行企业相... 详细信息

利用2008年上交所与深交所强制要求部分企业披露企业社会责任(CSR)这一准自然实验,以相同分析师数量作为同行企业判定标准,从同行企业的视角研究强制CSR披露对企业价值的影响。研究发现:第一,强制CSR披露政策使得披露企业的同行企业相比于非同行企业具有更为正面的股票市场反应;第二,这一正面影响在行业竞争压力较大企业、跟随者企业、融资约束较低企业以及国有企业等对竞争压力变化更为敏感的企业中更为显著。研究结论表明,强制CSR披露政策削弱了披露企业的竞争优势,降低了同行企业的竞争压力,因此相比于非同行企业,披露企业的同行企业具有较高的企业价值。

关键词：企业社会责任企业价值同行效应市场竞争

An accelerated life test model for harmonic drives under a segmental stress history and its parameter optimization

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Chinese Journal of Aeronautics 2015年第6期28卷 1758-1765页

作者： Zhang Chao wang Shaoping wang Zimeng wang xingjian School of Automation Science and Electrical Engineering Beihang University Beijing 100191 China Science and Technology on Aircraft Control Laboratory Beihang University Beo'ing 100191 China

Harmonic drives have various distinctive advantages and are widely used in space drive mechanisms. Accelerated life test （ALT） is commonly conducted to shorten test time and reduce associated costs. An appropriate ALT modet is needed to predict the lifetime of harmonic drives with ALT data. However, harmonic drives which are used in space usually work under a segmental stress history, and traditional ALT models can hardly be used in this situation. This paper proposes a dedicated ALT model for harmonic drives applied in space systems. A comprehensive ALT model is established and genetic algorithm （GA） is adopted to obtain optimal parameters in the model using the Manson fatigue damage rule to describe the fatigue failure process and a cumulative dam- age method to calculate and accumulate the damage caused by each segment in the stress history. An ALT of harmonic drives was carried out and experimental results show that this model is acceptable and effective.

关键词： Accelerated life testing Cumulative fatigue damagelaw Genetic algorithm Harmonic drive Segmental stress history

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甲烷掺氢旋流预混燃烧回火特性研究

工程热物理学报 2024年第6期45卷 1570-1578页

作者：储旭丁思宇李嘉斌杨阳赵洪亮朱民王兴建清华大学能源与动力工程系北京100084 国家管网集团北方管道公司压缩机组维检修中心廊坊065000

在节能减排与碳中和大背景下,燃气轮机燃烧室燃料逐渐向富氢方向发展。燃料掺氢后,燃烧过程更容易发生回火现象,需要对掺氢燃烧回火规律进行探究。本文选取了带钝体旋流预混燃烧室开展甲烷掺氢–空气的预混燃烧数值模拟研究,湍流模型采... 详细信息

在节能减排与碳中和大背景下,燃气轮机燃烧室燃料逐渐向富氢方向发展。燃料掺氢后,燃烧过程更容易发生回火现象,需要对掺氢燃烧回火规律进行探究。本文选取了带钝体旋流预混燃烧室开展甲烷掺氢–空气的预混燃烧数值模拟研究,湍流模型采用SST k-ω模型,湍流燃烧模型采用火焰面生成模型(FGM);准确地计算湍流火焰速度对回火现象的预测非常重要,因此对进度变量输运方程中源项的封闭考虑了掺氢对层流火焰传播速度的影响。数值模型与方法得到了实验验证,并进一步探究了当量比、入口平均轴向速度、钝体壁面热边界条件对回火现象的影响。结果表明降低当量比、提高入口平均轴向速度以及增强壁面换热对回火现象具有抑制作用。本文所总结的回火规律对于掺氢燃烧室设计具有指导意义。

关键词：掺氢燃烧 FGM 回火旋流预混燃烧

Distributed bearing-based formation control of unmanned aerial vehicle swarm via global orientation estimation

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Chinese Journal of Aeronautics 2022年第1期35卷 44-58页

作者： Yuwei ZHANG xingjian wang Shaoping wang Xinyu TIAN A School of Automation Science and Electrical Engineering Beihang UniversityBeijing 100191China Science and Technology on Aircraft Control Laboratory Beihang UniversityBeijing 100191China Ningbo Institute of Technology Beihang UniversityNingbo 315800China

Most existing formation control approaches for Unmanned Aerial Vehicle(UAV)swarm assume that global position and global coordinate frame are directly available for each *** extend the application domain,this paper proposes a distributed bearing-based formation control scheme,without any reliance on global position or global coordinate *** interactions among UAVs are described by a directed topology with two-leader *** address the issue of unavailable global coordinate frame,we first present a distributed orientation estimation law for each UAV to determine its orientation under the coordinate frame of the first *** on the orientation estimation,we then design a bearing-based formation control law to globally asymptotically track target moving ***,simulation results are provided to validate the proposed method,which show that the translation,scale and orientation of the formation can be flexibly controlled via two leaders.

关键词： Bearing measurement Formation control Global orientation estimation Two-leader structure Unmanned aerial vehicles

Active fault-tolerant control strategy of large civil aircraft under elevator failures

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Chinese Journal of Aeronautics 2015年第6期28卷 1658-1666页

作者： wang xingjian wang Shaoping Yang Zhongwei Zhang Chao School of Automation Science and Electrical Engineering Beihang University

Aircraft longitudinal control is the would lead to catastrophic accident of aircraft. most important actuation system and its failures This paper proposes an active fault-tolerant control （AFTC） strategy for civil aircraft with different numbers of faulty elevators. In order to improve the fault-tolerant flight control system performance and effective utilization of the control surface, trim- mable horizontal stabilizer （THS） is considered to generate the extra pitch moment. A suitable switching mechanism with performance improvement coefficient is proposed to determine when it is worthwhile to utilize THS. Furthermore, AFTC strategy is detailed by using model following technique and the proposed THS switching mechanism. The basic fault-tolerant controller is designed to guarantee longitudinal control system stability and acceptable performance degradation under partial elevators failure. The proposed AFTC is applied to Boeing 747-200 numerical model and simulation results validate the effectiveness of the proposed AFTC approach.

关键词： Active fault-tolerant control Longitudinal control Model following Performance improvementcoefficient Trimmable horizontalstabilizer

Liquid vaporization under thermodynamic phase non-equilibrium condition at the gas-liquid interface

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Science China(Technological Sciences) 2020年第12期63卷 2649-2656页

作者： wang xingjian LAFON Patrick SUNDARAM Dilip YANG Vigor Department of Mechanical and Civil Engineering Florida Institute of TechnologyMelbourneFlorida 32901USA Department of Mechanical and Nuclear Engineering The Pennsylvania State UniversityUniversity ParkPA 16802USA School of Aerospace Engineering Georgia Institute of TechnologyAtlantaGA 30332USA

Liquid vaporization under thermodynamic phase non-equilibrium condition at the gas-liquid interface is investigated over a wide range of fluid state typical of many liquid-fueled energy conversion systems. The validity of the phase-equilibrium assumption commonly used in the existing study of liquid vaporization is examined using molecular dynamics theories. The interfacial mass flow rates on both sides of the liquid surface are compared to the net vaporization rate through an order-of-magnitude *** indicated that the phase-equilibrium assumption holds valid at relatively high pressures and low temperatures,and for droplets with relatively large initial diameters(for example,larger than 10 μm for vaporizing oxygen droplets in gaseous hydrogen in the pressure range from 10 atm to the oxygen critical state). Droplet vaporization under superheated conditions is also explored using classical binary homogeneous nucleation theory,in conjunction with a real-fluid equation of state. It is found that the bubble nucleation rate is very sensitive to changes in saturation ratio and pressure;it increases by several orders of magnitude when either the saturation ratio or the pressure is slightly increased. The kinetic limit of saturation ratio decreases with increasing pressure,leading to reduced difference between saturation and superheat conditions. As a result,the influence of nonequilibrium conditions on droplet vaporization is lower at a higher pressure.

关键词： liquid vaporization droplet vaporization superheated vaporization thermodynamic phase equilibrium thermodynamic phase non-equilibrium vapor nucleation