基于196的智能交通信号机控制器的设计

基于实时交通流信息,以交叉口综合燃油消耗最小为控制目标,硬件采用多余度设计,大大提高了控制器的安全性和可靠性.采用多种通信方式便于系统功能扩展和互连.在保证交叉口通行能力的状态下,减少能源消耗,改善城市环境.能够实时记录路口交通状况,有助于未来的交通分析规划和改进控制算法.     

自抗扰锁相跟踪系统设计与仿真

针对锁相跟踪中的抗扰问题,提出了一种新的方案,通过二阶广义积分器将参考信号分解为 ２路正交信号,在滤波的同时得到精确的相位.数字频率合成器作为信号发生器具有高稳定性和高精确性,可以通过比较参考信号和 DDS 的相位误差,引入自抗扰控制算法,适应锁相跟踪系统对算法进行改进,输出DDS 的频率控制字.最后,通过 MATLAB 仿真结果表明,该控制器具有很强的鲁棒性和高抗扰性,能够有效地抑制不确定负荷扰动的影响.     

基于改进遗传算法的交通信号配时优化模型

针对当前交叉口信号配时方案相互孤立,未能有效达到区域交通控制最优化的问题,提出一种面向多交叉口信号控制方案的优化配时模型。文章分析了多交叉口交通流特征,利用元胞传输模型作为基础模型对多交叉口间受控的交通流进行模拟。根据多交叉口路网中影响交通量的被控参数特征,以及交通信号控制准确性、实时性等需求的分析,提出改进的遗传算法。结合DISCO交叉口数值模拟软件,对文中模型进行了数值模拟。数值模拟结果表明:文中模型能够通过配时调节适应交叉口间交通流的变化,道路车辆平均延迟时间较其他方案小,是一种实际配时控制器可采用的优化模型。     

交叉路口交通灯分级模糊控制器的研究和实现

模糊逻辑能很好地描述交叉口交通流的随机性和不确定性,因此非常适合应用于路口交通信号灯的控制.给出了一种采用分级模糊控制器进行路口信号灯控制的方法,以及模糊控制方法的结构、控制规则.最后由单片机实现信号灯的模糊控制,并对该控制器进行了仿真研究.结果表明它可以有效改善交叉路口的通行能力.     

基于改进粒子群算法的PID-CMAC控制器设计

小脑关节模型网络具有计算简单、学习速度快等特点,设计PID和CMAC的复合控制器既能够发挥PID控制器鲁棒性强的特点,又能够利用CMAC学习获取的知识根据输入的变化快速地做出响应,并能够提高控制系统的抗干扰能力.本文采用改进的粒子群算法对PID的控制参数进行优化,并在此基础上设计了一种新型的PID-CMAC复合控制器,通过仿真试验表明,该控制策略能够提高整个系统的控制品质.     

基于鲁棒优化模型的单交叉口交通信号配时的研究

针对城市交通道路单交叉口多相位的控制问题,考虑到各相位交通流具有不确定性的特性,在以交叉口车均延误最小为控制目标的基础上,提出了基于情景的鲁棒优化模型,并针对该优化模型以相位绿灯时间和周期时长为控制变量,采用了遗传算法进行优化。最后,以某交叉路口为例进行了仿真实验,并将确定性模型与鲁棒模型的结果进行了对比。结果表明,鲁棒模型所求得的交通信号配时方案能够更为有效地应对交通流不确定性导致的随机差异,具有较强的鲁棒性。     

基于神经网络的电动舵回路容错控制方法研究

为了克服电动舵回路故障和非线性因素的影响,提出一种基于神经网络误差反馈学习的电动舵机容错控制器设计方法,根据电动舵机系统动力学特征建立系统非线性数学模型,采用反馈误差学习控制律进行神经网络容错控制,由参考信号和实际输出信号对比产生的误差信号驱动神经网络学习从而产生控制信号,以达到实现容错重构控制的目的,仿真结果表明,神经容错网络控制器能够达到满意的控制效果。     

基于数字式锁相环的双向差动相位解调法设计

设计了应用于高精度干涉测量系统的双向差动相位解调法,利用锁相环的分频特性对测量信号进行降频处理,增加计数脉冲的数量,再结合双向差动相位解调法对信号进行鉴相,从而提高测量分辨力.在He-Ne双频激光外差偏振干涉信号处理实验装置中进行了实验,证明了该方法能够提高测量精度.     

基于单片机和CPLD的无刷直流电机系统

基于高速单片机和复杂可编程逻辑器件(CPLD)设计了一种具有霍尔位置传感器接口电路、电流采样电路以及编码器接口电路的无刷直流电机伺服控制器.该控制器可以实现无刷直流电机的有位置传感器控制和无位置传感器控制.以霍尔位置传感器的位置信号作为电机的换向信号并对该信号进行六倍频处理作为速度反馈,从而实现对电机的转速控制,给出了该控制系统的硬件结构设计和软件流程设计.试验结果表明:该无刷直流电机控制系统能够较好地实现电机的转速控制,为电机控制系统的设计提供了新思路.     

基于电子车牌的交叉口感应信号控制方法研究

提出了一种基于电子车牌的交叉口感应信号控制方法,该方法通过设置在交叉口处的阅读器与装有有源电子标签车辆互动,得到路段区间上的车辆信息。以车辆密度作为感应控制绿灯是否延长的评价标准,车辆密度高于阈值则绿灯延续,反之,切换相位。通过仿真对比分析表明,改进后的感应控制策略能够在高饱和度路口实现实时有效交通信号控制,克服了以车辆间隔时间作为绿灯延长标准的感应控制在高饱和度下失效的弊端,提高了城市交叉口绿灯利用率。     

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.     

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....     

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.