国防科技大学(电磁)-铁军二师技术报告

第六届“飞思卡尔”杯全国大学生智能汽车竞赛技术报告学校：国防科学技术大学队伍名称：电磁铁军二师参赛队员：孟德远季明江秦键指导老师：李炎杨云赵海洋全国大学生智能汽车竞赛技术报告关于技术报告和研究论文使用授权的说明本人完全了解第六届“飞思卡尔”杯全国大学生智能汽车邀请赛关保留、使用技术报告和研究论文的规定，即：参赛作品著作权归参赛者本人，比赛组委会和飞思卡尔半导体公司可以在相关主页上收录并公开参赛作品的设计方案、技术报告以及参赛模型车的视频、图像资料，并将相关内容编纂收录在组委会出版论文集中。参赛队员签名：带队教师签名：日期：目录第I页目录摘要„„„„„„„„„„„„„„„„„„„„„„„„„„„„ⅰABSTRACT„„„„„„„„„„„„„„„„„„„„„„„„„ⅱ第1章绪论„„„„„„„„„„„„„„„„„„„„„„„„„11.1背景介绍„„„„„„„„„„„„„„„„„„„„„„„11.1.1智能小车竞赛背景„„„„„„„„„„„„„„„„11.1.2课题研究意义„„„„„„„„„„„„„„„„„„21.2电磁车体系结构„„„„„„„„„„„„„„„„„„„„31.2.1硬件系统„„„„„„„„„„„„„„„„„„„„41.2.2软件系统„„„„„„„„„„„„„„„„„„„101.3电磁车关键技术„„„„„„„„„„„„„„„„„„„111.4论文结构安排„„„„„„„„„„„„„„„„„„„„12第2章硬件系统设计及车体机械优化„„„„„„„„„„„„„132.1硬件系统设计„„„„„„„„„„„„„„„„„„„„132.1.1电源管理系统设计„„„„„„„„„„„„„„„132.1.2电机驱动系统设计„„„„„„„„„„„„„„„142.1.3主控器系统设计„„„„„„„„„„„„„„„„172.1.4传感器系统设计„„„„„„„„„„„„„„„„212.2车体机械优化„„„„„„„„„„„„„„„„„„„„302.2.1转向性能优化„„„„„„„„„„„„„„„„„302.2.2差速性能优化„„„„„„„„„„„„„„„„„322.2.3车体重心优化„„„„„„„„„„„„„„„„„322.2.4舵机灵敏度优化„„„„„„„„„„„„„„„„332.2.5主动式电磁传感器的机械实现„„„„„„„„„„33第3章软件系统设计„„„„„„„„„„„„„„„„„„„„363.1初始化程序设计„„„„„„„„„„„„„„„„„„„363.1.1系统时钟初始化„„„„„„„„„„„„„„„„36全国大学生智能汽车竞赛技术报告3.1.2输入输出端口初始化„„„„„„„„„„„„„„373.1.3实时中断模块初始化„„„„„„„„„„„„„„373.1.4PWM模块初始化„„„„„„„„„„„„„„„373.1.5串行通信模块初始化„„„„„„„„„„„„„„383.1.6模数转换模块初始化„„„„„„„„„„„„„„383.1.7脉冲累加模块初始化„„„„„„„„„„„„„„383.2位置解算算法设计„„„„„„„„„„„„„„„„„„393.2.1滤波与归一化„„„„„„„„„„„„„„„„„393.2.2小车位置解算算法设计„„„„„„„„„„„„„413.3横向控制算法设计„„„„„„„„„„„„„„„„„„433.3.1舵机控制算法算法设计„„„„„„„„„„„„„433.3.2主动式电磁传感器巡线算法设计„„„„„„„„„453.4纵向控制算法设计„„„„„„„„„„„„„„„„„„463.4.1速度规划算法设计„„„„„„„„„„„„„„„463.4.2电机控制算法设计„„„„„„„„„„„„„„„47第4章调试环境与调试„„„„„„„„„„„„„„„„„„„484.1调试环境与调试方法„„„„„„„„„„„„„„„„„484.1.1调试软件实时调试„„„„„„„„„„„„„„„484.1.2双机通信实时调试„„„„„„„„„„„„„„„484.1.3MATLAB与EXCEL数据分析„„„„„„„„„„494.2调试流程及调试结果„„„„„„„„„„„„„„„„„494.2.1位置算法仿真分析„„„„„„„„„„„„„„„494.2.2电机PI参数测试„„„„„„„„„„„„„„„524.3整车联调及调试结果„„„„„„„„„„„„„„„„„53第5章结论„„„„„„„„„„„„„„„„„„„„„„„„„58致谢„„„„„„„„„„„„„„„„„„„„„„„„„„„„59参考文献„„„„„„„„„„„„„„„„„„„„„„„„„„60摘要第i页摘要本文以第六届全国大学生智能汽车竞赛为背景，设计并实现了基于主动式电磁传感器的电磁小车。整个系统涉及由交变电流产生的空间磁场建模分析，车模机械结构调整，驱动电路、主控器电路和传感器电路设计，信号处理，位置算法设计，控制算法设计和整车联合调试等多个方面。本文主要创新点如下：1．提出了基于三次多项式曲线拟合的位置解算算法。该算法采用三次多项式来拟合通电导线周围磁场强度变化曲线，从而解算出小车相对赛道的偏移距离。该算法在满足实时性与检测精度的前提下，对复杂赛道具有很强的适应性。2．给出了基于赛道曲率的“阿克曼转向”控制算法。该算法通过位置偏差计算出赛道曲率，然后应用“阿克曼转向模型”计算出转角控制量。该转向控制算法能适应各种曲率的赛道，克服了已有方法在大半径赛道中的抖动现象。关键词：智能车；电磁导航；多项式曲线拟合；阿克曼转向模型全国大学生智能汽车竞赛技术报告ABSTRACTThispaperisbasedonthe6th“FreescaleCup”NationalUniversitySmartcarCompetition.Theelectromagneticsmartcarwithactiveelectromagneticsensorsisdesignedandimplemented.Theoverallworkduringthesystemdevelopmentincludesmodelanalysisofspatialmagneticfieldproducedbymutativecurrent,themechanicalstructureadjustment,circuitrydesignofthedriver,controllerandsensor,signalprocessing,designoflocalizationalgorithm,designofcontrolanddebuggingalgorithm.Themaininnovativepointsofthispaperinclude:1.Arobustlocalizationalgorithmwhichisbasedontri-polynomialispresented.Itusestri-polynomialtofitthespatialmagneticfielddistribution,andthencomputesthepositionbetweenthecarandwire.Thealgorithmhasverystrongadaptabilitytothecomplicatedmatchpathwhilesatisfyingtherequirementofrealtimeanddetectionaccuracy.2.A“Ackermannsteer”controlalgorithmwhichisbasedonmatchpathcurvatureispresented.Thealgorithmuseslocationtocomputecurvature,andthenapply“Ackermannsteermodel”tocomputethecontrolparametersonturningangle.Thesteercontrolalgorithmcanadapttothematchpathofvariouscurvaturesandovercomethephenomenonoftrembleinsmallcurvature.WORDS:smartcar,electromagneticnavigation,polynomialfittingcurve,Ackermannsteermodel第四章调试环境与调试第3页第1章绪论1.1背景介绍1.1.1智能小车竞赛背景教育部为了加强大学生实践、创新能力和团队精神的培养，在已举办的全国大学生数学建模、电子设计、机械设计、结构设计等4大竞赛的基础上，经研究决定，委托教育部高等学校自动化专业教学指导委员会主办每年一度的全国大学生智能汽车竞赛，并成立了由教育部、自动化分教委、清华大学、飞思卡尔半导体公司等单位领导及专家组成的组委会。全国大学生“飞思卡尔”杯智能汽车竞赛同其他体育竞技比赛一样，前四届比赛设立了光电组与摄像头组两个赛题组别，而第五届新增加了电磁组。该竞赛以“立足培养，重在参与，鼓励探索，追求卓越”为指导思想，旨在促进高等学校素质教育，培养大学生的综合知识运用能力、基本工程实践能力和创新意识，激发大学生从事科学研究与探索的兴趣和潜能，倡导理论联系实际、求真务实的学风和团队协作的人文精神。摄像头组是指赛车使用透镜成像原理进行道路检测，光电组主要是使用光电传感器如红外传感器采集路径信息，电磁组则主要通过采用通电导线产生的电磁场对智能车进行引导。参赛车辆分别按照不同技术组别进行开发，分组竞争。该竞赛涵盖了控制、模式识别、传感技术、电子、电气、计算机、机械及车辆工程等多个学科的科技创意性比赛。比赛使用大赛组委会统一提供的竞赛车模，光电组使用的是A型车模，电磁组使用的是B型车模，摄像头组使用的是C型车模。采用飞思卡尔公司提供的8位或16位微控制器作为核心控制单元，以各组限定的传感器感知赛道信息，自主构思控制方案及系统设计，包括处理器选型、传感器系统设计、硬件系统设计和软件系统设计。最终，使改装后的车模沿着赛道自主行驶，在最短的时间内到达终点完成比赛。从智能汽车竞赛第一届开始，我校就十分关注并积极参与进来。经过多年参赛实践，积累了大量知识和经验，在硬件设计、控制算法、调试手全国大学生智能汽车竞赛技术报告段等各方面都打下了坚实基础。我校在历届比赛中，取得了全国一等奖3次、赛区一等奖5次、省级1等奖3次、二三等奖若干的好成绩，并争取在今年的比赛中向全国特等奖冲刺。图1-1赛道模拟图1.1.2课题研究意义基于主动式电磁传感器的智能小车系统设计，是智能小车应用电磁感应定律，使用电磁传感器获取交流导线附近的空间磁场强度后进行信号处理分析，通过位置解算算法计算出小车相对于通电导线的偏移量，使用“阿克曼转向模型”得出期望转角，计算出小车前方赛道的大致形状，从而通过规划控制算法得出预期运行轨迹与运行速度，使智能小车沿着赛道行驶。从上届的比赛情况来看，目前的电磁车存在以下几点缺点：（1）多数电磁车只使用了一个方向的电磁传感器，空间磁场感知能力不强；（2）位置解算算法都是基于无限长直导线设计的，在弯道中存在一定的误差；（3）舵机控制都是直接建立位置偏差与舵机转角的关系，在变曲率赛道上适应性不强。本文针对上述存在的问题，分别提出了改进的方案：（1）提出了双排传感器方案，每排传感器上都有4个X方向电磁传第四章调试环境与调试第5页感器及两个Y方向传感器，因此可以感知到两个位置的空间二维磁场，大大提高了磁场感知能力；（2）对单排传感器的4个X方向电磁传感器的值进行了三次多项式曲线拟合，很好地描述了该排传感器所在位置的磁场分布情况，拟合曲线的极大值的位置便是黑线所在位置，因此算法不依赖于赛道情况，具有很好的鲁棒性。（3）本文通过小车的偏移位置求出运动轨迹的曲率，然后通过阿克曼转向模型将小车运动轨迹的曲率、小车速度和转角联系起来，使小车的转向更加精确、运动更加稳定。总的来说，本课题可以提高我校智能小车的整体水平，使我校选手在第六届“飞思卡尔杯”全国大学生智能汽车竞赛中取得优异成