隧道式炉二自由度PID控制的MATLAB仿真研究

该文利用MATLAB仿真软件对二自由度PID在隧道式炉中的应用进行仿真研究，并给出仿真结果。仿真结果表明，隧道式炉采用二自由度PID控制能够实现给定跟踪性能和扰动抑制性能同时达到最佳。     

基于二自由度PID前馈解耦的恒温恒湿控制系统设计

设计一种基于二自由度PID前馈解耦的恒温恒湿控制系统,利用阶跃响应实验测得系统响应曲线,结合机理法搭建数学模型,设计解耦环节,把多变量耦合控制系统处理为多回路互不干扰的单变量控制系统,使用二自由度PID控制器,调节PID参数,使外部干扰响应性能最优,目标值滤波器处理温湿度设定值,使目标值响应性能也达到最优.仿真结果表明,该控制系统减小了温度和相对湿度的互相干扰,保证了温湿度值平稳不抖动.     

基于二自由度PID的水温控制

针对一阶惯性加滞后的水温加热控制系统,采用结构简单、参数易于整定、抗干扰能力良好的二自由度PID进行控制。通过大量实验,对二自由度PID控制与常规PID控制的控制性能进行比较,发现通过改变二自由度系数b值的大小可以实现温控系统的无超调控制和超调控制,同时验证了该控制策略具有良好的设定值跟踪能力和抗干扰性,有效地提高了系统的控制性能。     

一种基于粒子群算法的二自由度PID控制器优化设计

粒子群算法在解决复杂问题的优化设计上具有算法简单,计算速度快的优点,将粒子群算法引入到二自由度PID控制器的参数整定中,用于改进二自由度PID控制器参数整定的效率并进行了仿真实验,仿真结果表明,系统同时具有了最优的目标值跟踪特性和干扰抑制特性.     

半主动悬架PID控制与Fuzzy-PID控制对比研究

选取某车型悬架参数,在MATLAB/Simulink中建立二自由度四分之一车半主动悬架模型。以改善乘坐舒适性和操作稳定性为目标,对半主动悬架分别设计了常规PID控制和Fuzzy-PID控制。以随机路面作为激励进行仿真,仿真结果表明:相比被动悬架,两种控制方案均使悬架性能得到了改善,但Fuzzy-PID控制对悬架性能改善明显优于PID控制。     

汽车主动悬架控制策略对比研究

为提高汽车主动悬架减振性能,建立了简化的1/4车体二自由度主动悬架模型,分别结合PID控制、模糊控制和自适应模糊PID控制方式设计了1/4车二自由度主动悬架控制器。以C级路面白噪声随机信号为激励,利用MATLAB/Simulink软件对车辆主动悬架的三种控制方式进行了仿真,选取车身垂直振动速度及加速度、悬架动挠度和轮胎动载荷等指标进行控制效果评价。结果表明:基于自适应模糊PID控制的主动悬架较其他控制方式能明显改善汽车行驶平顺性,可有效抑制汽车主动悬架的振动。     

轮式移动机器人路径跟踪的模糊自整定PID控制

本文建立了二自由度轮式移动机器人路径跟踪的动力学模型,并设计了自整定模糊PID控制器,利用模糊推理的方法,对PID控制器的参数进行自动整定。仿真实验用常规增量式PID控制和自整定模糊PID控制算法结合进行航向跟踪,结果表明该算法与常规PID算法相比,系统误差减少了20%左右,响应时间减小到原来的0.4,有效地改善了控制器的动态性能,同时表现出了较好的自适应能力,路径跟踪仿真结果表明,轮式移动机器人能够迅速向目标路径靠拢,并能平稳地践踏规划路径。     

鲁棒二自由度PID控制

针对工业过程控制对象,将内模控制与二自由度PID控制有机结合,提出一种鲁棒二自由度PID控制方法,可以有效抑制参数变化对系统的影响,使系统同时获得良好的目标值跟踪特性、干扰抑制特性和鲁棒性.理论分析和仿真结果表明了这一方法的有效性.     

不完全微分型PID控制的神经元实现

给出从不完全微分型PID算法派生出的神经元PID控制器，并利用MATLAB／SIMULINK仿真软件对该控制器在某隧道式炉中的应用进行仿真研究。仿真结果表明．不完全微分PID控制的神经元实现不但具有不完全微分型PID控制的优点而且还具有神经元控制的自适应特点。     

永磁伺服系统前馈型模糊二自由度控制研究

针对传统PID控制抗干扰能力差以及智能化控制方法计算复杂、模型难建立、不易应用等问题,在对模糊控制理论和二自由度原理分析的基础上,提出了一种在工程中易于实现的前馈型模糊二自由度控制策略。通过对前馈型二自由度模型化简变换,在变换后模型的基础上引入了模糊控制规则,使其同时具备模糊控制和二自由度控制的优点,实现了实时跟踪和自动整定控制参数的功能。利用Matlab工具建立了前馈型模糊二自由度控制系统仿真模型。研究结果表明,系统转速无超调,响应速度和扰动恢复时间比传统PID控制提高一倍。该控制方法具有良好的动、静态性能,实现了永磁伺服系统高速化、强抗干扰能力,提高了永磁伺服系统控制精度,为解决高精度数控系统提供了一种可行、易于实现的控制策略。     

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.     

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....     

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。     

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.