检索结果-南通市图书馆

Disturbance observer-based backstepping control for hypersonic flight vehicles without use of measured flight path angle

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2021年第2期34卷 396-406页

作者： yao Lu Beijing Aerospace Automatic Control Institute Beijing 100854China National Key Laboratory of Science and Technology on Aerospace Intelligence Control Beijing 100854China

In this paper a nonlinear control method is proposed for the tracking control of hypersonic flight vehicles. The designed control laws do not utilize the measured flight path angle due to its inferior accuracy in practical engineering. For this, an estimated flight path angle is designed via the measurements of the altitude and velocity. A tracking differentiator is designed for constructing nonlinear disturbance observer which is used to estimate the model uncertainties including the parameter indeterminacies and external disturbances in the channels of velocity and pitch rate. A robust high-order differentiator is introduced to avoid the employment of the measured flight path angle and estimate the lumped disturbance in dynamics of flight path angle. Meanwhile, the possible saturation of the control inputs is considered and compensated by the auxiliary states. The boundness of closed-loop signals is proved through the Lyapunov theory. Comparative simulations are carried out and the results demonstrate the effectiveness of the proposed method.

关键词： Anti-saturation Backstepping Disturbance observer Flight control Hypersonic flight vehicle State estimation

Experimental and Statistical Analysis of Fatigue Behavior in Zr-based Bulk Metallic Glass

在线全文

学校读者我要写书评

暂无评论

稀有金属材料与工程 2024年第11期53卷 3010-3016页

作者： yao Zhifeng Qiao Jichao Pelletier Jean-Marc yao yao School of Civil Engineering Xi'an University of Architecture&TechnologyXi'an 710055China Dongguan Sanhang Innovation Institute Dongguan 523808China School of Mechanics Civil Engineering and ArchitectureNorthwestern Polytechnical UniversityXi'an 710072China Institut National des Sciences Appliquées de Lyon Universitéde LyonLyon F-69621France School of Materials and Chemical Engineering Xi'an Technological UniversityXi'an710021China

Three-point bending fatigue experiments were conducted on a typical Zr-based bulk metallic glass(BMG)at ambient temperature to investigate the fatigue behavior under cyclic loading *** show that the stress amplitude-cycles to failure(S-N)curve of the Zr-based BMG is determined,and the fatigue endurance limit is 442 MPa(stress amplitude).To evaluate the probability-stress amplitude-cycles to failure(P-S-N)curve,an estimation method based on maximum likelihood was proposed,which relies on statistical principles to estimate the fatigue life of the material and allows for a reduction in the number of samples required,offering a cost-effective and efficient alternative to traditional testing *** experimental results align with the American Society for Testing and Materials(ASTM)standard,indicating the reliability and accuracy of this estimation method in evaluating the fatigue behavior of Zr-based BMG.

关键词： bulk metallic glass P-S-N curve fatigue test statistical analysis

An adaptive distributed auction algorithm and its application to multi-AUV task assignment

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2023年第5期66卷 1235-1244页

作者： WANG Yu LI HuiPing yao yao School of Marine Science and Technology Northwestern Polytechnical UniversityXi’an 710072China Jiangsu Automation Research Institute Lianyungang 222061China

The task assignment of multi-agent system has attracted considerable attention;however,the contradiction between computational complexity and assigning performance remains to be *** this paper,a novel consensus-based adaptive optimization auction(CAOA)algorithm is proposed to greatly reduce the computation load while attaining enhanced system payoff.A new optimization scheme is designed to optimize the critical control parameter in the price update role of auction algorithm which can reduce the searching complexity in obtaining a better bidding *** this new scheme,the CAOA algorithm is *** the developed algorithm is applied to the multi-AUV task assignment problem for underwater detection mission in complex *** simulation and comparison studies verify the effectiveness and advantage of the CAOA algorithm.

关键词： task assignment multi-agent systems consensus-based adaptive optimization auction intelligent algorithm multiple AUVs

Life:Ordinary World-Speech by Lu yao at Northwest University in December 1991

在线全文

学校读者我要写书评

暂无评论

Frontiers of Literary Studies in China-Selected Publications from Chinese Universities 2022年第2期16卷 186-198页

作者： LU yao JIAO Haimin(record) 不详 Documentary Department Shaanxi Media ConvergenceXi'an 710061China

ⅠI have not done much preparation for today,since it is the end of the year and I have my hands *** the past years,I have had several opportunities to express my opinions,and I do not really have any new ***,I look forward to taking some specific questions from you to exchange our ideas,so I hope this lecture will be rewarding for you.

关键词： really since Northwest

SC-CO_(2)与工业乳化炸药破岩效应的等效试验

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

工程科学学报 2025年第2期47卷 249-258页

作者：蒋楠姚颖康朱斌罗学东江汉大学省部共建精细爆破国家重点实验室武汉430056 江汉大学爆破工程湖北省重点实验室武汉430056 中国地质大学(武汉)工程学院武汉430074

如何定量化核算SC-CO_(2)(超临界二氧化碳)破岩效率是非炸药类破岩技术在实际工程应用时重点关注的内容.本研究基于爆破当量理论计算和现场爆破试验的研究方法,通过工程类比法进行工业乳化炸药等效当量计算,选择典型代表性花岗岩及泥岩... 详细信息

如何定量化核算SC-CO_(2)(超临界二氧化碳)破岩效率是非炸药类破岩技术在实际工程应用时重点关注的内容.本研究基于爆破当量理论计算和现场爆破试验的研究方法,通过工程类比法进行工业乳化炸药等效当量计算,选择典型代表性花岗岩及泥岩场地,设计进行了SC-CO_(2)与工业炸药破岩效应等效对比现场试验;基于现场破岩等效现场试验测试数据,对比分析试验过程中SC-CO_(2)与工业炸药破岩体积、破岩区域形态、大块率和单耗等破岩区域特征及参量数据.研究结果表明:当SC-CO_(2)破岩体积较大时,其致裂破岩范围的长短轴较长,并且随着剪切片厚度的增加,泥岩场地二氧化碳单耗的下降速率增大,二氧化碳单耗是炸药单耗的6~11倍.SC-CO_(2)破岩技术大块率较高,而炸药爆炸应力波分布均匀,大块率较小.SC-CO_(2)破岩地表振速远小于工业炸药破岩,工业炸药爆破测点合振速值为SC-CO_(2)破岩测点合振速值的9~11倍,SC-CO_(2)破岩对周边环境震动影响较小.SC-CO_(2)破岩测点合应力峰值高于工业炸药破岩,SC-CO_(2)破岩试验中各测点合应力值为炸药破岩试验中对应测点值的1.2~1.6倍.

关键词： SC-CO_(2) 工业炸药等效破岩动力效应破岩体积

Robust Control for Static Loading of Electro-hydraulic Load Simulator with Friction Compensation

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2012年第6期25卷 954-962页

作者： yao Jianyong JIAO Zongxia yao Bin School of Mechanical Engineering Nanjing University of Science and Technology Nanjing 210094 China Science and Technology on Aircraft Control Laboratory Beihang University Beijing 100191 China School of Mechanical Engineering Purdue University West Lafayette IN 47907 USA

Load simulator is a key test equipment for aircraft actuation systems in hardware-in-the-loop-simulation. Static loading is an essential function of the load simulator and widely used in the static/dynamic stiffness test of aircraft actuation systems. The tracking performance of the static loading is studied in this paper. Firstly, the nonlinear mathematical models of the hydraulic load simulator are derived, and the feedback linearization method is employed to construct a feed-forward controller to improve the force tracking performance. Considering the effect of the friction, a LuGre model based friction compensation is synthesized, in which the unmeasurable state is estimated by a dual state observer via a controlled learning mechanism to guarantee that the estimation is bounded. The modeling errors are attenuated by a well-designed robust controller with a control accuracy measured by a design parameter. Employing the dual state observer is to capture the different effects of the unmeasured state and hence can improve the friction compensation accuracy. The tracking performance is summarized by a derived theorem. Experimental results are also obtained to verify the high performance nature of the proposed control strategy.

关键词： electro-hydraulic load simulator robust control friction compensation feedback linearization LuGre model nonlinear control state estimation

A systematic framework to understand central bank digital currency

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2018年第3期61卷 206-213页

作者： Qian yao Institute of Digital Money of the People’s Bank of China

The ongoing research and development of digital fiat currency(DFC) have triggered attention of policy makers, regulators and the industrial and academic communities. But there is not yet a clear idea and blueprint of what DFC looks like. This paper establishes a systematic framework to analyze the essence and connotation of DFC from four dimensions: currency value, technical aspects, means of implementation and application scenarios. It is argued that DFC is a credit-based currency in terms of value, a crypto-currency from a technical perspective, an algorithm-based currency in terms of implementation and a smart currency in application scenarios. Compared with existing private digital currencies and electronic currencies, DFC will be equipped with brand new and higher qualities. The goal of Chinese DFC is to contribute to more stable value, more secure data, more powerful regulation, stronger empowerment of individuals in payment activities and smarter application. Chinese DFC should have qualities that enable it to provide better service for the public, to offer effective tools for macroeconomic control and to lay a solid foundation for Reg Tech development.

关键词： digital fiat currency credit-based currency crypto-currency algorithm-based currency smart currency central bank digital currency

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

异构无人系统协同控制研究进展

工程科学学报 2025年第1期47卷 66-78页

作者：郭兴李擎姚其家鲁小雅北京科技大学自动化学院北京100083 工业过程知识自动化教育部重点实验室北京100083

面对复杂化、多样化和立体化的任务需求,异构无人系统将空、地、海跨域优势互补,最大化提升系统各方面能力,为未来协同作战和智慧民生提供有力的技术保障.首先,梳理了国内外在跨域协同领域出台的推动性文件,介绍了异构无人系统在军用、... 详细信息

面对复杂化、多样化和立体化的任务需求,异构无人系统将空、地、海跨域优势互补,最大化提升系统各方面能力,为未来协同作战和智慧民生提供有力的技术保障.首先,梳理了国内外在跨域协同领域出台的推动性文件,介绍了异构无人系统在军用、科研院所和民用等三方面的实际应用.其次,针对异构无人系统关键技术之一的协同控制,分别阐述了异构无人系统协同控制在一致性、轨迹跟踪和编队‒合围等三方面的最新进展.此外,还特别讨论了在不同通信条件下协同控制所面临的挑战和解决方案.其中,由于一致性和轨迹跟踪存在上层控制理论性和下层控制可行性的区别,进一步从滑模控制、自适应控制、反步控制和自适应动态规划等四方面对轨迹跟踪研究展开阐述.然后,为了更好地促进异构无人系统协同控制在实际中的应用,通过总结前人相关工作,讨论了其在多约束控制与实时性、多任务切换控制和跨域通信下稳定性等三方面亟需解决的技术瓶颈.最后,综合异构无人系统协同控制研究现状和实际需求来看,指出了其在深度强化学习与分布式博弈、人机交互以及反群体智能等三方面的发展趋势.

关键词：异构无人系统协同控制跨域协同任务需求技术瓶颈

同方期刊数据库

WAVEFORM RELAXATION METHODS OF NONLINEAR INTEGRAL-DIFFERENTIAL-ALGEBRAIC EQUATIONS

在线全文

学校读者我要写书评

暂无评论

Journal of Computational Mathematics 2005年第1期23卷 49-66页

作者： yao-linJiang DepartmentofMathematicalSciences Xi'anJiaotongUniversityXi'an710049China

In this paper we consider continuous-time and discrete-time waveform relaxation meth-ods for general nonlinear integral-differential-algebraic equations. For the continuous-time case we derive the convergence condition of the iterative methods by invoking the spec-tral theory on the resulting iterative operators. By use of the implicit difference forms,namely the backward-differentiation formulae, we also yield the convergence condition of the discrete waveforms. Numerical experiments are provided to illustrate the theoretical work reported here.

关键词： nonlinear integral-differential-algebraic equations waveform relaxation parallel solutions convergence of iterative methods engineering applications