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引入控制量变化率约束的双层协同轨迹规划器

宇航学报 2024年第1期45卷 101-109页

作者：温岳冯肖雪谢天龚柏春吴云华北京理工大学自动化学院北京100081 南京航空航天大学航天学院南京210016

针对亚音速飞行器编队飞行轨迹规划约束复杂、求解困难的问题,提出了一种引入控制量变化率约束的双层亚音速飞行器协同轨迹规划器。首先,引入控制量变化率约束以保证轨迹可行性,为了避免增加新的状态方程而增加计算量,采用拉格朗日插值... 详细信息

针对亚音速飞行器编队飞行轨迹规划约束复杂、求解困难的问题,提出了一种引入控制量变化率约束的双层亚音速飞行器协同轨迹规划器。首先,引入控制量变化率约束以保证轨迹可行性,为了避免增加新的状态方程而增加计算量,采用拉格朗日插值多项式计算控制变量变化率,将其作为求解最优控制问题伪谱法的约束条件。然后,使用顶层单飞行器规划器在不考虑多飞行器协同约束的条件下使用较少配点的伪谱法快速求解每个飞行器的粗略轨迹结果,求解结果使用拉格朗日插值作为底层多飞行器规划器的初值。底层多飞行器规划器使用更多的配点以确保求解的精度,在考虑多飞行器协同约束条件下进行伪谱法求解,以解决伪谱法初值敏感问题并提高优化效率。最后仿真结果表明了所提方法的有效性,与引入虚拟控制量而增加状态方程方法相比,此方法计算量更小,求解效率更优,满足协同轨迹规划的要求。

关键词：编队飞行轨迹规划变化率约束双层规划器

农户种植饲草料投入产出及种植行为影响因素研究——以内蒙古巴彦淖尔市杭锦后旗和磴口县为例

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中国农机化学报 2024年第7期45卷 276-281,290页

作者：乌云花永梅吕月许黎莉内蒙古农业大学经济管理学院呼和浩特市010010

国内消费结构及农业结构调整背景下,中国畜牧业迅速发展,饲草料需求不断增加,但是国内饲草料供应不足、安全问题凸显。在“粮改饲”试点旗县进行实地调研,了解当地农户饲草料种植的投入产出情况,利用Logit、2SLS及LIML模型对农户种植饲... 详细信息

国内消费结构及农业结构调整背景下,中国畜牧业迅速发展,饲草料需求不断增加,但是国内饲草料供应不足、安全问题凸显。在“粮改饲”试点旗县进行实地调研,了解当地农户饲草料种植的投入产出情况,利用Logit、2SLS及LIML模型对农户种植饲草料行为的影响因素进行实证研究。结果显示,调查区域农户种植的饲草料主要以青贮玉米、苜蓿及燕麦草为主,种植苜蓿草的经济效益比其他饲草料高,2021年苜蓿草纯收益可达22 005元/hm^(2),比青贮玉米和燕麦草分别高出4 590元/hm^(2)元和12 180元/hm^(2),但是农户种植饲草料尤其苜蓿草的积极性并不高。探究农户选择种植饲草料行为的影响因素,发现政策激励、土地禀赋及组织制度因素对农户饲草料种植行为有显著的正向影响,提出政府应该尽快建立完善的土地流转市场体系,助力农户扩大种植规模,顺利进行种植业结构调整,加大饲草料种植面积,促进为养而种的良性循环,解决养殖业饲草料短缺问题以及鼓励各类合作社发挥合作制度优势,帮助农户降低种植饲草料的投入成本,拓宽饲草料的销售渠道,增加农民收入的对策建议。

关键词：饲草料投入产出农户行为影响因素计量模型

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弱全局信息下巨星座多路并发熵均衡路由策略

宇航学报 2024年第7期45卷 1089-1099页

作者：吴云华初思仪李宗凌毛雨荷岳程斐南京航空航天大学航天学院南京210016 北京空间飞行器总体设计部北京100094 哈尔滨工业大学(深圳)空间科学与应用技术研究院深圳518055

为保障地面系统对巨星座信息的高效获取,考虑实际卫星感知能力的约束,提出一种弱全局信息下巨星座多路并发熵均衡路由策略。首先,根据星座运行模式构建簇群,同时考虑簇的感知能力,建立弱全局信息下的“星-星/星-地”数据传输模型。其次... 详细信息

为保障地面系统对巨星座信息的高效获取,考虑实际卫星感知能力的约束,提出一种弱全局信息下巨星座多路并发熵均衡路由策略。首先,根据星座运行模式构建簇群,同时考虑簇的感知能力,建立弱全局信息下的“星-星/星-地”数据传输模型。其次,综合考虑网络结构、数据流量分布和信息多点频发等因素,对现有算法进行改进,引入熵作为评估节点负载分布均匀度的量化指标,引入惩罚因子对路径成本进行动态调整,并通过滚动窗口法规划巨星座多路并发情况下的对地传输路径。最后,以Starlink一期部署的卫星为例,进行数值仿真,验证所提方法的有效性。

关键词：巨星座弱全局信息数据获取多路径熵均衡低轨卫星

不同喷丸强度对FGH96粉末高温合金表面完整性的影响研究

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航空制造技术 2024年第12期67卷 38-43页

作者：盖鹏涛武赟华曹子文魏大盛付雪松中国航空制造技术研究院北京100024 大连理工大学大连116024 北京航空航天大学北京100191

粉末高温合金涡轮盘由于长期在高温高应力等极端环境下服役,通常需对其表面进行喷丸强化处理,以满足严苛的性能需求。基于此,本文系统研究了不同喷丸强度对镍基粉末合金FGH96的表面完整性的影响。结果表明,经喷丸处理后,合金近表层晶粒... 详细信息

粉末高温合金涡轮盘由于长期在高温高应力等极端环境下服役,通常需对其表面进行喷丸强化处理,以满足严苛的性能需求。基于此,本文系统研究了不同喷丸强度对镍基粉末合金FGH96的表面完整性的影响。结果表明,经喷丸处理后,合金近表层晶粒发生细化,产生了一层硬化层,并在表层引入了较大的残余压应力。此外,在合金近表面产生了塑性变形层,其深度随喷丸强度增加而增加,由原始状态下的5μm增加到0.25 mmA喷丸强度下的117μm。随喷丸强度的增加,合金的表面粗糙度、表面硬度值、硬化层深度、表层残余压应力和残余应力层深均呈增加趋势。该研究结果可为粉末高温合金喷丸强化工艺的设计和选取提供一定的数据基础。

关键词：粉末高温合金喷丸强化表面完整性残余应力塑性变形

Cooperative game theory-based steering law design of a CMG system

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Journal of Systems Engineering and Electronics 2023年第1期34卷 185-196页

作者： HUA Bing NI Rui ZHENG Mohong wu yunhua CHEN Zhiming School of Astronautics Nanjing University of Aeronautics and AstronauticsNanjing 210000China

Spacecraft require a large-angle manoeuvre when performing agile manoeuvring tasks, therefore a control moment gyroscope(CMG) is employed to provide a strong ***, the control of the CMG system easily falls into singularity, which renders the actuator unable to output the required moment. To solve the singularity problem of CMGs, the control law design of a CMG system based on a cooperative game is proposed. First, the cooperative game model is constructed according to the quadratic programming problem, and the cooperative strategy is constructed. When the strategy falls into singularity, the weighting coefficient is introduced to carry out the strategy game to achieve the optimal strategy. In theory, it is proven that the cooperative game manipulation law of the CMG system converges, the sum of the CMG frame angular velocities is minimized, the energy consumption is small, and there is no output torque error. Then, the CMG group system is *** the CMG system is near the singular point, it can quickly escape the singularity. When the CMG system falls into the singularity, it can also escape the singularity. Considering the optimization of angular momentum and energy consumption, the feasibility of the CMG system steering law based on a cooperative game is proven.

关键词： control moment gyroscopes(CMG) cooperative game theory steering laws

Application of an M13 bacteriophage displaying tyrosine on the surface for detection of Fe^(3+) and Fe^(2+) ions

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Virologica Sinica 2015年第6期30卷 410-416页

作者： Xiaohua Guo Chuncheng Niu yunhua wu Xiaosheng Liang College of Life Science &Hubei Provincial Key Laboratory for Protection and Application of Special Plants on wuling Area South-Central University for Nationalities

Ferric and ferrous ion plays critical roles in bioprocesses,their influences in many fields have not been fully explored due to the lack of methods for quantification of ferric and ferrous ions in biological system or complex *** this study,an M13 bacteriophage(phage) was engineered for use as a sensor for ferric and ferrous ions via the display of a tyrosine residue on the P8 coat *** interaction between the specific phenol group of tyrosine and Fe^(3+)./ Fe^(2+).was used as the *** electron microscopy showed aggregation of the tyrosine-displaying phages after incubation with Fe^(3+) and Fe^(2+).The aggregated phages infected the host bacterium *** phenomenon could be utilized for detection of ferric and ferrous *** ferric ions,a calibration curve ranging from 200 nmol/L to 8 μmol/L with a detection limit of 58 nmol/L was *** ferrous ions,a calibration curve ranging from 800 nmol/L to 8μmol/L with a detection limit of 641.7 nmol/L was *** assay was specific for Fe^((3+)) and Fe^((2+)) when tested against Ni^(2+),Pb^(2+),Zn^(2+),Mn^(2+),Co^(2+),Ca^(2+),Cu^(2+),Cr^(3+),Ba^(2+),and K^+.The tyrosine displaying phage to Fe^(3+) and Fe^(2+) interaction would have plenty of room in application to biomatenals and bionanotechnology.

关键词： M13 bacteriophage tyrosine display ferric ion ferrous ion aggregation

Singularity analysis for single gimbal control moment gyroscope system using space expansion method

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Chinese Journal of Aeronautics 2018年第4期31卷 782-794页

作者： yunhua wu Feng HAN Bing HUA Zhiming CHEN Feng YU School of Astronautics Nanjing University of Aeronautics and Astronautics School of Astronautics Harbin Institute of Technology

Control Moment Gyroscope（CMG） is an effective candidate for agile satellites and large spacecraft attitude control because of its powerful torque amplification capability. The most serious situation, however, in using CMG is the inherent geometric singularity problem, where there＇s no torque output along a particular direction. Space expansion method has been proposed in this work for the singularity analysis. Based on inverse mapping transformation, an expanded Jacobian matrix which is a full rank square matrix is obtained. The singular angle sets of the 3-parallel cluster and pyramid cluster are distinguished using space expansion method. An effective hybrid steering strategy, able to deal with the elliptic singularity, is further proposed. Simulation results demonstrate the excellent performance of the proposed steering logic compared to the generalized singular robust logic and pseudo inverse logic in terms of energy consumption and torque error.

关键词： Agile spacecraft Control moment gyro Singularity analysis Space expansion method Steering strategy

High precision attitude dynamic tracking control of a moving space target

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Chinese Journal of Aeronautics 2019年第10期32卷 2324-2336页

作者： yunhua wu Mohong ZHENG Wei HE Feng WANG Zhiming CHEN Bing HUA Micro-Satellite Research Center Nanjing University of Aeronautics and AstronauticsNanjing 210016China Shanghai Electro-Mechanical Engineering Institute Shanghai 201109China Research Center of Satellite Technology Harbin Institute of TechnologyHarbin 150001 f China

On-orbit spacecraft face many threats,such as collisions with debris or other ***,perception of the surrounding space environment is vitally important for on-orbit *** require a dynamic attitude tracking ability with high precision for such *** paper aims to address the above problem using an improved backstepping *** tracking mission is divided into two phases:coarse alignment and fine *** the first phase,a traditional saturation controller is utilized to limit the maximum attitude angular velocity according to the actuator’s *** the second phase,the proposed backstepping controller with different virtual control inputs is applied to track the moving *** fulfill the high precision attitude tracking requirements,a hybrid attitude control actuator consisting of a Control Moment Gyro(CMG)and Reaction Wheel(RW)is constructed,which can simultaneously avoid the CMG singularity and RW saturation through the use of an angular momentum optimal management strategy,such as null ***,five simulation scenarios were carried out to demonstrate the effectiveness of the proposed control strategy and hybrid actuator.

关键词： Space moving target Attitude dynamic tracking Backstepping controller Improved virtual control input Hybrid actuator

A study of PID and L1 adaptive control for automatic balancing of a spacecraft three-axis simulator

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International Journal of Intelligent Computing and Cybernetics 2018年第2期11卷 269-284页

作者： Bing Hua Lin Chen yunhua wu Zhiming Chen College of Astronautics Nanjing University of Aeronautics and AstronauticsNanjingChina

Purpose–The three-axis simulator relies on the air film between the air bearing and the bearing seat to achieve weightlessness and the frictionless motion condition,which is essential for simulating the micro-disturbance torque of a satellite in outer ***,at the beginning of the experiment,the disturbance torque caused by the misalignment between the center of gravity of the simulator and the center of rotation of the bearing is the most important factor restricting the use of the space three-axis *** order to solve this problem,it is necessary to set the balance adjustment system on the simulator to compensate the disturbance torque caused by the *** paper aims to discuss these ***/methodology/approach–In this paper,a study of L1 adaptive automatic balancing control method for micro satellite with motor without other actuators is proposed.L1 adaptive control algorithm adds the low-pass filter to the control law,which in a certain sense to reduce the high-frequency signal and speed up the response time of the controlled *** the same time,by estimating the adaptive parameter uncertainty in object,the output error of the state predictor and the controlled object can be stabilized under Lyapunov condition,and the robustness of the system is also *** automatic balancing method of PID is also studied in this ***–Through this automatic balancing mechanism,the gravity disturbance torque can be effectively reduced down to 10−6 Nm,and the automatic balancing time can be controlled within 7 ***/value–This paper introduces an automatic balancing *** experimental results show that the mechanism can greatly improve the convergence speed while guaranteeing the control accuracy,and ensuring the feasibility of the large angle maneuver of spacecraft three-axis simulator.

关键词： Automatic balancing Gravity disturbance torque L1 adaptive control Spacecraft three-axis simulator