GPS及加速计组合量车速的发展趋势和应用毕业论文.doc

GPS及加速计组合测量车速的发展趋势和应用 摘 要 车辆速度是汽车道路试验中的重要参数，它与车轮力(力矩)、踏板力、车轮转速(转角)等参数相结合，对汽车整车动态性能的分析、制动系统的性能匹配和ABS(防抱死制动系统)的开发有着重要的意义和应用价值。目前车速的测量主要使用五轮仪和相对式光电编码器。五轮仪有两种，一种是常规的五轮仪，车轮由被检车辆拖曳前进测量出距离信号，另一种是非接触式五轮仪，利用光学原理测量出车辆与地面的相对移动距离信号。这两种五轮仪体积都比较大，安装复杂，精度高的往往价格很高。光电式编码器使用测周法或测频法，通过测量相连脉冲的间隔时间或单位时间内的脉冲数转换算出车速，但路况和安装不当会使编码器在行使过程中产生抖动，影响测量精度。本设计采用GPS信号与加速度计相结合的方式测量车速，实现速度信号的高精度实时采集。 关键词：GPS；加速速度传感器；卡普曼滤波法；数据融合；车速 ABSTRACT Speed is the important parameters of automotive road test, and the wheel (moment), pedal force, the wheel speed (corner etc), combined with parameters of automotive dynamic performance analysis, braking system performance and ABS (ABS) development has important significance and application value. Currently the main use of measuring speed and five rounds relative photoelectric encoder. Five round apparatus has two kinds, one kind is the conventional five rounds, wheel by screening vehicle hauling measured distance signal, another is noncontact five rounds, optical instrument measuring principle and ground vehicles relative distances signal. These two kinds of five rounds instrument installation is larger, the volume of high accuracy is complex, often high price. Photoelectric encoder USES measuring method of frequency measurement method, or weeks, by measuring the time interval or connected pulse unit time pulses of several conversion speed, but calculate road, and improper installation will make encoder in exercise generated during the jitter, measuring precision. This design USES GPS signal with a combination of accelerometer measurement speed, high speed signal of the real-time data acquisition. Keywords: GPS, Accelerating Speed Sensor, Kalman Filtering Method, Data Fusion, Speed  目 录 摘 要 I ABSTRACT II 第1章 绪 论 1 1.1 概述 1 1.2 课题研究的目的和意义 1 1.3 课题国内外研究现状 2 1.4本课题研究内容 2 第2章 车速测量系统硬件设计 4 2.1 GPS系统的定位原理 4 2.1.1 GPS系统的理论基础 4 2.1.2 GPS系统的工作原理 4 2.1.3 定位误差分析 5 2.2 GPS信号接收模块 6 2.3 GPS坐标转换 7 2.3.1 投影变换 7 2.3.2 坐标变换 9 2.3.3 坐标转换公式的简化及其有效性 9 2.4 MMA7260Q加速度传感器功能特点