基于图像识别的自主寻迹智能小车设计

针对小车自主寻迹行驶的要求,提出了一种基于ARM平台的摄像头循迹小车系统。小车系统以ST公司生产的STM32F103ZET6为微控制器,通过安装在小车前的OV7725摄像头采集道路信息。然后对路径图像信息进行除噪、黑线提取和路径识别后获得路径信息。再根据不同的路径信息控制电机,进而调整小车速度和方向,最终实现小车沿设定路径行驶。摄像头采集的图像和小车速度能够实时显示在LCD和数码管上。实验证明,小车实现了自主循迹功能,具有良好的鲁棒性和实时性。     

一种基于80C51单片机控制的寻迹小车设计

寻迹小车采用光电传感器来识别白色路面中央的黑色引导线,通过80C51单片机实现对转向舵机和驱动电机的PWM控制,使小车实现快速稳定地寻线行驶.分模块阐述了寻迹小车的原理、软硬件设计及制作过程.针对路径特点对寻迹小车的方向控制和速度控制提出了舵机分级转向、速度分段控制的解决方案.实验表明,寻迹小车能够较快速、平稳地完成对各种曲率引导线的寻线行驶任务.     

竞赛机器人小车设计的几个关键问题及解决

介绍了竞赛机器人小车的设计和具体实现。机器人小车以SST公司的SST89E564RD单片机为控制器，辅以传感器模块和驱动器模块。传感器模块采用的是反射式可见光传感器，利用达林顿管对反射光强进行放大。控制模块采用传感器信号来确定小车状态和辨认路线，依据直行算法控制机器人小车进行直线行走，通过预置导航地图来改变小车的前进方向，从而达到自主寻迹的目的。     

基于单片机的寻迹小车的研究与实现

寻迹机器小车是一个很好的应用单片机技术的设计。本系统所用的单片机采用性能优秀的AVR单片机的ATmega16L芯片,由其通过I/O口控制小车的前进后退以及转向。自制了单片机电路板和程序下载ISP线,能够顺利完成小车的寻迹。同时还可以扩展控制小车行进时的路线,可以改变程序文件来变换寻迹的路线。所完成的设计可以直接应用于单片机的教学之中,使本设计有了重要的应用价值。     

自主寻迹智能小车的激光路径跟随系统设计

文章针对光电式智能小车的路径信息采集与跟随问题,通过理论分析与计算,提出了一种基于自主寻迹智能小车的激光路径跟随系统设计方案。该方案将激光传感器安装在高性能舵机上,用控制舵机转角的方式使激光传感器时刻跟随路径,从而控制智能小车的转向机构、电机驱动机构等部件,提高了智能小车寻迹行驶的速度,降低了智能小车冲出跑道的概率。     

基于FPGA的视觉导航小车设计与实现

视觉导航作为新兴起的技术,受众多研究者的青睐.设计了以现场可编程门列阵(FPGA)为控制核心的自主导航小车,采用一种新颖的自适应路径识别算法实现路径的识别与提取,并结合圆弧路线规划和控制策略完成小车的自主导航控制.自适应路径识别算法使导航小车可以适应多种光照和路面条件.测试结果表明,小车能够在不同光照条件下的实验室和露天田径跑道环境中实现较好的导航效果,在田径跑道上的导航测试中,小车的最高运行速度达到3.5 m/s.     

红外寻迹小车寻迹控制策略的改进

基于高职红外寻迹小车实训教学平台,提高小车系统的抗干扰能力,使寻迹运动更快、更平稳。在传统红外寻迹电路板的基础上,通过增加串并转换芯片74HC595与54VHC4051多路开关选择器,实现了寻迹管的分时扫描及A/D采样,将传统路径信息的硬阈值二值化方式转化为具有场地适应能力的软阈值量化方式,并基于PID算法实现了小车位置偏移的调整。经对比实验,证实新的控制策略使小车对场地的适应能力得到了提高,巡弯道时更加平稳。     

电磁导航智能寻迹小车方向控制算法的分析与应用

针对电磁式智能小车系统路径信息处理复杂的问题,提出了一种基于延伸有效增减区间的优化PID算法。首先,对磁场信号检测原理作了介绍,提出了一种新的传感器布置方案;其次,提出使用归一化处理来解决数据不对称的问题,通过MATLAB仿真的方法分析了前瞻高度与位置解算函数线性度的关系,并提供了扩展单调区间宽度的方法;最后,对传统PID算法的各个环节分别进行了改进,提出舍弃积分控制环节来克服转向的时滞性,使用位置偏差的二次幂作为比例系数来保证转向角度与弯道的吻合度,在微分控制环节当中引入非线性环节来达到优化路径的目的。在保证小车寻迹精度的前提下,改进后的算法相对于传统PID算法使小车的车速提高了约20%。实验表明,该算法能够实现小车识别复杂路径、自主寻迹的功能。     

基于CMOS传感器的智能小车设计

介绍了一种基于Freescale公司的16位HCS12单片机的一种智能车控制系统,它采用黑白CMOS摄像头作为路径识别装置,通过图像识别提取路径信息.利用单片机产生PWM波,控制小车速度和转向,利用自制的速度传感器来获取小车当前速度,实现速度的闭环控制,增加小车的稳定性,较之常规的光电传感器识别路径方案,利用摄像头传感器可以获取更多的路径信息.测试结果表明,智能车能按任意给定的黑色引导线更能以较快的速度平稳地运行.     

基于MC9S12XS128单片机智能寻迹小车的设计

本文给出了智能小车寻迹系统的软硬件方案设计和开发流程.采用飞思卡尔MC9S12XS128单片机作为智能小车控制芯片,设计了电源、电机驱动、激光传感器以及测速等模块,小车的速度、转向控制采用PID控制方法,测试结果表明,小车能够平稳实现寻迹功能.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with     

Journal of Donghua University ( English Edition) Contents of Volume 31

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