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Room thermal load prediction based on analytic hierarchy process and back-propagation neural networks

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Building Simulation 2022年第11期15卷 1989-2002页

作者： Xin Tan Zhenjing Zhu Guoxin Sun linfeng wu College of Mechanical Engineering Inner Mongolia University of Science and TechnologyBaotou 014010China

Accurate prediction of the heat load is the basic premise of intelligent regulation of the heating system,which helps to realize effective management of heating,ventilation,air conditioning *** the problem that the weight of each influencing factor is not taken into account in the current heat load prediction and is not highly targeted,this article deeply explores the influence of different factors on the room heat load,and we propose a method to calculate room heat load prediction based on the combination of analytic hierarchy process(AHP)and back-propagation(BP)neural ***,eight environmental factors affecting the heat load are selected as prediction inputs through parametric analysis,and then the weights of each input are determined by AHP and normalize the prediction data by combining expert opinions,and finally do one-to-one training the quantified score and the room heat load to predict the future heat load by BP neural *** simulation tests show that the mean absolute relative error(MARE)of the proposed prediction method is 5.40%.This article also verifies the influence of different expert opinions on the stability of the *** results show that the proposed method can guarantee higher prediction accuracy and stability.

关键词： heating system heat load prediction analytic hierarchy process back-propagation neural network

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转炉用扭力杆系统振动理论研究

振动与冲击 2017年第6期36卷 97-101页

作者：吴林峰王文华北水利水电大学机械学院郑州450008

扭力杆系统的动态特性对转炉设备工作的可靠性有着重要影响,研究其振动频率和阵型是设备自主创新的关键技术之一。综合考虑扭力杆系统实际结构组成,提出了均质杆和集中质量杆一端铰支另一端简支反对称弯曲振动梁、均质杆和集中质量杆一... 详细信息

扭力杆系统的动态特性对转炉设备工作的可靠性有着重要影响,研究其振动频率和阵型是设备自主创新的关键技术之一。综合考虑扭力杆系统实际结构组成,提出了均质杆和集中质量杆一端铰支另一端简支反对称弯曲振动梁、均质杆和集中质量杆一端固支另一端简支反对称弯曲振动梁等四种振动模型。以某厂150 t氧气顶吹转炉扭力杆系统为例进行了理论计算。结果表明,扭力杆系统振动模型采用集中质量杆一端固支和一端简支反对称弯曲振动梁模型更合理。并用有限元法对其正确性进行了验证,两种方法的计算结果吻合,都可以对扭力杆系统进行研究,但是理论解更为简单方便,便于工程技术人员直接引用,为指导工程实际设计和生产提供了理论基础。

关键词：转炉扭力杆系统振动梁模型理论解有限元解

尾座式垂直起降无人机在时变侧风干扰下的轨迹跟踪控制

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清华大学学报（自然科学版） 2022年第1期62卷 179-188页

作者：吴林峰李春文清华大学自动化系北京100084

该文针对尾座式垂直起降无人机面临的时变侧风干扰问题,设计了一种基于新型姿态提取算法的轨迹跟踪控制方法。首先,根据侧风干扰与无人机姿态的关系建立数学模型,在此模型基础上推导出一种利用无人机滚转角的新型姿态提取算法,显著降低... 详细信息

该文针对尾座式垂直起降无人机面临的时变侧风干扰问题,设计了一种基于新型姿态提取算法的轨迹跟踪控制方法。首先,根据侧风干扰与无人机姿态的关系建立数学模型,在此模型基础上推导出一种利用无人机滚转角的新型姿态提取算法,显著降低了干扰力。在反步式控制方法的基础上,采用嵌套饱和函数方法对控制输入进行限制,解决推力限幅问题,并通过PD+前馈控制方法解决姿态跟踪控制问题。此外,采用指令滤波器解决了时变侧风干扰造成的期望姿态无法求导的问题。结果表明:只要滤波频率足够大,轨迹跟踪误差便可达到任意小,并通过仿真实验验证了其有效性。

关键词：尾座式无人机垂直起降侧风干扰

Adaptive Active Disturbance Rejection Control based on Coupling Coefficient with Applications to Flight Environment Simulation System

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Adaptive Active Disturbance Rejection Control based on Coupl...

基于优化VMD和连续隐马尔科夫模型的管道堵塞状态评估

第43届中国控制会议

作者： linfeng wu Qiumeng Qian Chao Zhai Hehong Zhang School of Future Technology China University of Geosciences Science and Technology on Altitude Simulation Laboratory AECC Sichuan Gas Turbine Establishment College of Computer Science and Big Data Fuzhou University

The ability of a high-altitude test bench flight environment simulation system to accurately simulate high-altitude environmental parameters plays a crucial role in the performance testing and evaluation of aviation engines. However, the strong coupling between controlled pressure and temperature variables in the core air intake environment simulation subsystem, along with sensor measurement noise, limits the overall control quality of environmental parameters. For this purpose, this paper proposes an adaptive active disturbance rejection control based on coupling degree identification, abbreviated as AADRC, which efficiently matches the system control channels while solving the flight environment simulation control problems caused by variable coupling and measurement noise. Based on the relative gain array method, the coupling degree of the control variables of the linearized system is identified, providing a matched control loop for the high-temperature gas control valve and the lowtemperature gas control valve. Considering the impact of sensor measurement noise on the performance of active disturbance rejection control, an adaptive extended state observer with adaptive bandwidth adjustment method based on relative gain array method, referred to as AESO, is proposed.

关键词： ight environment simulation platform decoupled control algorithms relative gain array active disturbance rejection control coupling analysis extended state observer

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振动与冲击 2020年第22期39卷 214-222,233页

作者：伍林峰冯早朱雪峰昆明理工大学信息工程与自动化学院昆明650500 云南省矿物管道输送工程技术研究中心昆明650500

面向U型管堵塞状态演变过程中故障程度的评估问题,提出一种基于低频声压信号分析和连续隐马尔科夫模型(CHMM)的U型管堵塞状态评估方法。该方法利用声波作为激励来观测U型管沉积物的堆积程度,对不同堵塞状态下的低频声压信号进行变分模... 详细信息

面向U型管堵塞状态演变过程中故障程度的评估问题,提出一种基于低频声压信号分析和连续隐马尔科夫模型(CHMM)的U型管堵塞状态评估方法。该方法利用声波作为激励来观测U型管沉积物的堆积程度,对不同堵塞状态下的低频声压信号进行变分模态分解(VMD),根据分量幅值谱图确定变分模态分解的最佳模态分解数k并通过声压级变换筛选有效的IMF分量;然后提取有效IMF分量的多尺度熵(MSE)特征,构建反映U型管不同程度堵塞状态的特征向量,最后将特征向量用于CHMM模型训练,建立能对U型管堵塞状态进行评估的模型。通过对U型管不同程度堵塞状态的试验数据进行测试,评估结果表明:该模型能准确评估U型管堵塞状态的程度变化,具有一定的工程应用价值。

关键词： U型管声压信号变分模态分解(VMD) 堵塞状态连续隐马尔科夫模型(CHMM)

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中锰TRIP钢电阻点焊研究进展与展望

材料导报 2022年第10期36卷 156-162页

作者：刘腾朱政强吴蔺峰南昌大学机电工程学院南昌330031

面对日益严峻的环境问题,汽车工业应进一步减轻整车质量以实现节能减排的目标。传统质轻高强钢,如双相钢(DP)、相变诱发塑性钢(TRIP)和奥氏体钢等,因生产成本高、强塑积较低和冶金等问题限制了其应用。中锰TRIP钢强塑积可达30GPa%~60GP... 详细信息

面对日益严峻的环境问题,汽车工业应进一步减轻整车质量以实现节能减排的目标。传统质轻高强钢,如双相钢(DP)、相变诱发塑性钢(TRIP)和奥氏体钢等,因生产成本高、强塑积较低和冶金等问题限制了其应用。中锰TRIP钢强塑积可达30GPa%~60GPa%,实现了优异综合力学性能与质轻特点的良好结合,在车身轻量化方面具有极广的应用前景。本文从中锰TRIP钢微观组织演变规律与形变机理出发,探讨影响其电阻点焊接头质量的主要因素,概述了母材化学成分、微观结构、熔核几何尺寸和焊接工艺等方面对其质量的影响。通过分析焊接过程中奥氏体的马氏体相变、晶粒尺寸、形貌等特征,揭示了影响中锰TRIP钢焊点热影响区韧性的内在因素。综述了近年来先进高强钢(AHSS)的研究,阐述了AHSS三种典型焊点失效模式、失效内在机制与其影响因素,重点关注了焊点在拉剪试验中的断裂行为,提出了一种通过预测临界熔核尺寸以保证拔出失效(Pull-out failure,PF)的方法。最后,总结了焊后改性方面的最新研究,并展望了未来中锰TRIP钢电阻点焊的研究热点与方向。

关键词：中锰TRIP钢电阻点焊微观组织失效模式

VTOL Control of Tailsitter UAV Under Crosswind Disturbances

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VTOL Control of Tailsitter UAV Under Crosswind Disturbances

Endovascular Irradiation Prevents Sm ooth Muscle CellPro-liferation and Neointim alHyperplasia in Rabbits

第32届中国控制与决策会议

作者： linfeng wu Chunwen Li Qingqing Ding Chao Wang Le Zhu Xiyue Tan Department of Automation Tsinghua University

To solve the problem of crosswind disturbances and thrust boundedness for tailsitter vertical take-off and landing（VTOL） unmanned aerial vehicle（UAV） control,this paper presents a control method by taking advantage of the aircraft’s rolling freedom to decrease the crosswind disturbances and relax the restriction on maximum ***,a mathematical model was constructed to illustrate the relationship of wind direction,aircraft attitude and disturbance ***,a new attitude extraction algorithm using wind direction was designed based on the traditional backstepping control *** the control input was limited by saturated function method to solve the problem of thrust ***,a position controller for tailsitter aircraft was designed with simulation showing its effectiveness.

关键词： Tailsitter UAV Vertical Takeoff and Landing Crosswind Disturbances Thrust Boundedness

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Journal of Huazhong University of Science and Technology(Medical Sciences) 1999年第3期19卷 240-245页

作者： XU linfeng 1, wu Yudan 2, FENG Gansheng 1 1 Department of Radiology, Xiehe Hospital, Tongji Medical University, wuhan 430030 2Institute of Hematology, Xiehe Hospital, Tongji Medical University, wuhan 430030 Oguchi M, Yokota H, Nakagawa T, Yam Department of Radiology Xiehe Hospital Tongji Medical University Wuhan 430030

The present study examined the temporal responses and the efficacy of 192Ir HDR endovascular irradiation for preventing smooth muscle cell proliferation of rabbit iliac arteries after PTA with a cutting balloon catheter. Endovascular irradiation with 12 Gy was randomly performed on the one side of iliac arterial segment with the unirradiated side serving as a control. Animals were euthanatized 1, 2, 3, 4, 8 and 12 week(s) after angioplasty. Histopathological and immunohistochemical studies were carried out. Histopathology showed repair of the dissection by cellular accumulation and a striking reduction in the amount of neointimal hyperplasia in the irradiated arteries as compared with control vessels. A peak of PCNA positive ratio was in neointima of the control arterial segments at a week. 2 - 4 weeks after irradiation, the neointimal PCNA positive ratio was still significantly increased in the control arterial segments compared with the irradiated arterial segments. After 8 weeks, PCNA positive ratio was below 1 % in both irradiated arterial segments and the control. Our results showed that the 192Ir HDR afterloading irradiation with a dose of 12 Gy can be considered sufficient for inhibiting neointimal hyperplasia in angioplastized rabbit iliac arteries with cutting balloon catheter.

关键词： neointimal hyperplasia endovascular irradiation PCNA

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微型航空发动机推力矢量系统建模与控制

清华大学学报（自然科学版） 2020年第3期60卷 198-205页

作者：李颖杰吴林峰李春文清华大学自动化系北京100084

以微型航空发动机推力矢量系统为对象,对先进战机缩比验证机的推力矢量系统进行了建模与控制研究。对推力矢量系统建模,采用了机理模型结合试验数据的方法,引入了气动偏角与推力损失系数,对机理模型进行了修正。控制律设计采用改进后的... 详细信息

以微型航空发动机推力矢量系统为对象,对先进战机缩比验证机的推力矢量系统进行了建模与控制研究。对推力矢量系统建模,采用了机理模型结合试验数据的方法,引入了气动偏角与推力损失系数,对机理模型进行了修正。控制律设计采用改进后的广义最小方差方法,在保证响应速度的同时,相比传统广义最小方差方法降低了对控制参数的敏感性。最后在全工况区间对修正后的推力矢量系统进行了控制律的仿真验证,结果表明:所建立的基于改进广义最小方差控制律在经过修正的推力矢量系统模型上,具有良好的控制效果。

关键词：微型航空发动机推力矢量系统气动偏角推力损失系数改进广义最小方差控制