交流伺服系统分数阶PID改进型自抗扰控制

针对采用永磁同步电机驱动的火箭炮交流伺服系统存在摩擦、惯性力矩、变负载及不同工况下内外扰动等复杂非线性问题,考虑到自抗扰控制(ADRC)抗内外干扰能力强和分数阶PID控制动态性能好,设计了一种分数阶PID改进型自抗扰控制器(FOPID-IADRC)。为了取得良好的动态性能和减少参数计算量,采用分数阶PID控制器取代非线性状态误差反馈器;引入粒子群优化算法,对FOPID控制器的5个控制参数进行实时在线自整定。仿真和半实物台架实验结果表明：该控制策略能够有效抑制位置扰动,具有良好的动态性能和较强的抗干扰能力。     

ADRC串级控制在电加热炉温度控制中的应用研究

针对工业电加热炉温度具有非线性、大惯性、时滞,并且很难建立精确数学模型的特点,将自抗扰控制技术(ADRC)应用于EFPT实验装置中,模拟工业电加热炉温控系统,提出了串级自抗扰控制策略。在其外环采用扩张状态观测器、状态误差的非线性反馈、扰动估计补偿相结合的控制方法;在内环采用比例控制,以快速消除干扰。仿真和实验结果表明,该控制方法具有超调小、调节快的优点,系统的鲁棒性和抗干扰能力优于常规串级PID控制方法。     

自抗扰控制器的发展及其应用

本文介绍了自抗扰控制器(ADRC)的发展过程-从非线性PID到扩张状态观测器的产生,再到自抗扰控制器的形成。同时,全面阐述了自抗扰控制器(ADRC)的基本结构,参数整定原理并以具体实例验证了ADRC良好的控制性能．     

多色套准系统前馈自抗扰控制器设计

针对无轴传动凹印机对多色套准控制系统高精度和高稳定性的要求,提出了一种基于自抗扰控制(Active disturbance rejection control,ADRC)技术设计前馈控制器的方法。根据套准系统的工作机理,建立了多色套准系统的非线性耦合数学模型,并利用一阶泰勒公式对其进行了线性化。为了满足高速、高精度套准控制的要求,以建立的四色套准系统线性模型为基础,利用前馈和ADRC控制技术设计了套准系统前馈ADRC控制器,一方面采用前馈控制对各套准误差的已知干扰进行前馈补偿,另一方面采用ADRC对套准系统输入进行调节并对未知干扰进行主动估计和补偿。仿真结果表明,所设计的多色套准系统控制器有效地抑制了各种干扰对套准误差的影响,实现了高精度套准控制,具有比PID控制器更好的控制性能。     

3自由度柔性并联机构自抗扰控制研究

由于柔性并联机构传统控制策略存在轨迹跟踪精度误差较大的问题,设计了一种基于3-PRR柔性并联机构的自抗扰控制器(ADRC).首先,采用闭环矢量法得到了机构的输入输出Jacobian矩阵,为机构控制提供了输入值;然后,分别设计了PID控制器和ADRC控制器,运用李雅普诺夫(Lyapunov)函数证明了ADRC控制器的稳定性;最后,分别采用PID控制和ADRC控制研究了机构在3个方向的位移追踪误差.结果表明:ADRC控制器的位移轨迹跟踪误差比PID控制器低,控制精度高,反应速度快,稳定性强,验证了柔性并联机构ADRC控制的可行性.     

自抗扰技术在卫星姿态模拟系统中的应用

建立了高精度卫星姿态模拟系统用于光通信地面仿真试验,针对卫星轨迹特点,设计了一种改进的自抗扰控制算法。介绍了自抗扰控制技术的特点和控制原理,提出改进的伺服算法,为自抗扰算法引入了选择性积分项。针对系统±10″动态误差要求,设计了多阈值非线性函数,并添加状态判断模块实时更改非线性函数参数。同时,给出了算法主要参数的整定原则。然后,基于控制器开放伺服功能,给出了自抗扰控制的实现方法和计算流程。实验结果表明:系统具有良好的连续加减速能力,跟踪斜坡信号的动态误差为±6″;经对比,在跟踪卫星姿态轨迹时,自抗扰控制的抗干扰能力优于PID控制,跟随误差达到±7″,满足高精度姿态仿真要求。     

电驱动海洋绞车主动升沉补偿自抗扰控制系统

针对电驱动海洋绞车主动升沉补偿系统非线性时变的特点,提出了基于自抗扰控制（ADRC）的电驱动海洋绞车主动升沉补偿控制系统。首先对电驱动海洋绞车系统进行动力学分析,然后建立电驱动海洋绞车数学模型,进而建立主动升沉补偿自抗扰控制系统的仿真模型,并进行仿真分析。在不同海况、不同下放深度、不同缆绳直径和不同重物质量等情况下对该系统进行仿真,并与PID控制器进行比较,结果表明：当海况和电驱动海洋绞车控制系统模型参数发生变化时,控制器参数保持不变的情况下,自抗扰控制器仍然能保持良好的动态性能,比PID控制器具有更快的响应速度、更强的鲁棒性和抗干扰能力。     

液压机械传动装置泵-马达系统模糊自抗扰控制

针对液压机械传动装置(Hydraulic Mechanical Continuously Variable Transmission, HMCVT)在阶跃负载扰动、变速器输入转速扰动的影响下所引起的输出转速波动问题,以分矩汇速式液压机械传动装置中的泵-马达系统为研究对象,以系统稳速输出为控制目标,提出一种基于扰动补偿的模糊自抗扰控制(Active Disturbance Rejection Control, ADRC)方法。该方法采用模糊控制理论对自抗扰控制中的非线性误差反馈系数进行在线整定,利用扩张状态观测器(Extended State Observer, ESO)对系统总扰动进行实时观测,并通过前馈控制调节电-液比例阀阀芯位移来补偿变量泵斜盘摆角,最终实现HMCVT稳速控制。仿真结果表明,相比于传统PID控制,采用模糊自抗扰控制的液压机械传动装置在外负载和输入转速突变时,变量泵斜盘抖振幅度更小,系统稳速输出响应时间更短,抗扰动能力更强。     

轴向主动磁轴承的模糊自抗扰控制

为了实现轴向主动磁轴承的准确和稳定控制,根据模糊控制理论和自抗扰控制(ADRC)理论,设计了轴向主动磁轴承模糊自抗扰控制系统,采用模糊控制器整定ADRC中非线性控制参数,并且给出了其控制算法和控制系统的结构.利用软件Matlab/Simulink对所设计的控制系统进行了仿真研究,仿真结果表明:所设计的轴向主动磁轴承模糊自抗扰控制系统具有响应速度快、超调量小、抗干扰能力强和鲁棒性好等特点.     

发电机组柴油机转速自抗扰控制的应用

为提升发电机组用发动机的抗干扰能力,增强其竞争优势,从发动机转速控制角度设计一种基于扩张状态观测器变结构自抗扰控制器,来满足发电机组非线性、时变的工作特性。通过试验验证其设计的自抗扰控制算法与传统PID控制算法对发动机转速的控制效果。试验结果表明:发动机转速自抗扰控制算法能够满足发电机组稳态及动态频率特性需求,相对传统控制在抗扰性能上有所提高,满足跟踪需求。     

Minimal Realization of Linear Graph Models for Multi-physics Systems

An engineering system may consist of several different types of components,belonging to such physical"domains"as mechanical,electrical,fluid,and thermal.It is t...     

INTEGRAL EQUATION METHOD＇S APPLICATION IN HOLE-EDGE STRESS OF COMPOSITE MATERIAL PLATE WITH DIFFERENT SHAPED HOLES

The strength of composite plate with different hole-shapes is always one of the most important but complicated issues in the application of the composite material. The holes will lead to mutations and discontinuity to the structure. So the hole-edge stress concentration is always a serious phenomenon. And the phenomenon makes the structure strength decrease very quickly to form dangerous weak points. Most partial damage begins from these weak points. According to the complex variable functions theory, the accurate boundary condition of composite plate with different hole-shapes is founded by conformal mapping method to settle the boundary condition problem of complex hole-shapes. Composite plate with commonly hole-shapes in engineering is studied by several complex variable stress fimction. The boundary integral equations are founded based on exact boundary conditions. Then the exact hole-edge stress analytic solution of composite plate with rectangle holes and wing manholes is resolved. Both of offset axis loadings and its influences on the stress concentration coefficient of the hole-edge are discussed. And comparisons of different loads along various offset axis on the hole-edge stress distribution of orthotropic plate with rectangle hole or wing manhole are made. It can be concluded that hole-edge with continuous variable curvatures might help to decrease the stress concentration coefficient; and smaller angle of outer load and fiber can decrease the stress peak value.     

Non-monotonic material contrast in scanning ion and scanning electron images

30 keV Ga⁺ focused ion beam induced secondary electron (iSE) imaging was used to determine the relative contrast between several materials. The iSE signal compared from C, Si, Al, Ti, Cr, Ni, Cu, Mo, Ag, and W metal layers does not decrease with an increase in target atomic number Z₂, and shows a non-monotonic relationship between contrast and Z₂. The non-monotonic relationship is attributed to periodic fluctuations of the stopping power and sputter yield inherent to the ion–solid interactions. In addition, material contrast from electron-induced secondary electron (eSE) and backscattered electron (BSE) images using scanning electron microscopy (SEM) also shows non-monotonic contrast as a function of Z₂, following the periodic behavior of the stopping power for electron–solid interactions. A comparison of the iSE and eSE results shows similar relative contrast between the metal layers, and not complementary contrast as conventionally understood. These similarities in the contrast behavior can be attributed to similarities in the periodic and non-monotonic function defined by incident particle–solid interaction theory.     

Application of Feature Extraction through Convolution Neural Networks and SVM Classifier for Robust Grading of Apples

This paper proposes a novel grading method of apples,in an automated grading device that uses convolutional neural networks to extract the size,color,texture,an...     

分布动态载荷识别的抗噪处理

针对正交多项式频域法在用多种响应对矩形薄板进行载荷识别中抗噪性较差的问题,综合运用平均法、矩阵预处理和奇异值截断法等方法对之进行改善,并引入空间映射的思想,将该方法的应用范围拓展为复杂的模型.利用仿真算例,证实了该方法具有较好的抗噪性.     

基于MELTAC-N平台的核电厂安全级DCS环网研究与测试

针对工程实践中环网通讯相关问题的处理缺乏理论基础及国产化安全级DCS平台的开发缺乏成熟经验借鉴问题,对基于MELTAC-N平台核电厂安全级DCS环网的软硬件实现进行了研究。提出了安全级DCS环网双环网冗余设计、光切换开关设计等硬件设计方法,以及以RPR协议为基础,采用全数据收发策略的软件设计方法。在CPR1000安全级DCS平台上对安全级DCS环网的可靠性及实时性进行了评价,并进行了容错能力、响应时间及响应时间稳定性测试验证实验。结果表明,基于MELTAC-N平台安全级DCS环网软硬件设计具有较好的容错能力及响应时间稳定性。     

Short-Term Relay Quality Prediction Algorithm Based on Long and Short-Term Memory

The fraction defective of semi-finished products is predicted to optimize the process of relay production lines, by which production quality and productivity ar...     

End-to-End Multiview Gesture Recognition for Autonomous Car Parking System

The use of hand gestures can be the most intuitive human-machine interaction medium.The early approaches for hand gesture recognition used device-based methods....     

The laboratory simulation of abrasive wear

Abrasive wear has long been recognised as one of the most potentially serious tribological problems facing the operators of many types of plant and machinery; several industrial surveys have indicated that wear by abrasion can be responsible for more than 50% of unscheduled machine and plant stoppages. Locating the operating point of a tribological contact in an appropriate operational ‚map’︁ can provide a useful guide to the likely nature and origins of the surface degradation experienced in use, though care must be exercised in choosing the most suitable parameters for the axes of the plot. Laboratory testing of materials and simulations of machine contacts are carried out for a number of purposes; at one level for the very practical aims of ranking candidate materials or surface hardening treatments in order of their wear resistance, or in an attempt to predict wear lives under field conditions. More fundamentally, tests may be aimed at elucidating the essential physical mechanisms of surface damage and loss, with the longer term aim of building an analytical and predictive model of the wear process itself. In many cases, component surface damage is brought about by the ingress of hard, particulate matter into machine bearing or sealing clearances. These may be running dry although, more usually, a lubricant or service fluid is present at the interface. A number of standardised wear test geometries and procedures have been established for both two- and three-body wear situations, and these are briefly described. Although abrasive wear is often modelled as following an ‚Archard’︁ equation (i.e. a linear increase in material loss with both load and time, and an inverse dependence on specimen hardness) both industrial experience and laboratory tests of particularly lubricated contacts show that this is not always the case: increasing the hardness differential in an abrasively contaminated lubricated pair may not always reduce the rate of damage to the harder surface.     

ANGULAR DISTORTION ALLOWABLE VALUE AND ASSESS METHOD OF WELD ON COKE TOWER

A graph as the new engineering method for estimate the safety of bulging deformation of coke tower is proposed. Through stresses analysis of circumferential weld of coke tower and comparing the stresses produced by pressure with heat stress of steady state, residual stress, bending stress produced by both itself weight and wind loads, it showed that the stresses produced by pressure on the angle distortion are the main factor of equivalent stress of the combined stress. After comparing four kinds of stress controlling conditions, the relation to stress with depth of angular distortion, grade of curvature of angular distortion and half of region of angular distortion has been inferred. Graph of deformation allowable value of coke tower for different condition by angular distortion and half of region of angular distortion has been plotted. The five steps for its engineering use have been explained. The lighter the grade of curvature is, the larger of bulge allowance, may be, and the bigger of depth of angular distortion may pose too. For the coke tower with a popular structure of Dg 5 400 mm×28 mm, the result by graph is nearly more than the result of two formulas formed by other research, the error is less than 7.0%. But, the graph can be easily applied to different size of angular distortion.