激光导航论文：基于激光导航的果园拖拉机自动控制系统研究.doc

激光导航论文：基于激光导航的果园拖拉机自动控制系统研究【中文摘要】果园以其复杂的环境特征,致使机械自动化作业困难重重。本研究为实现果园机械自动化作业,以改装的福田欧豹拖拉机为研究对象,采用激光扫描仪为导航设备,设计了针对不同果园环境下的车辆自动导航控制系统,实现了模拟果园环境下拖拉机的直线和曲线自动行走功能,为果园机械自动化移动平台的建立准备了条件。主要研究的内容如下:(1)将激光测距技术应用于果树信息的采集,提出了一种新的果树定位信息提取方法,使果树定位更加精确。(2)针对果园果树难以定位的问题,建立了以拖拉机为主体的车辆动坐标系,完成激光扫描果树信息从极坐标形式到直角坐标形式的转换,将果园中模糊的果树位置信息,通过车辆动作标系实现定位,为障碍物、路径的识别及导航路径的拟合提供数据支持。(3)将实际驾驶经验与车辆运动学模型相结合,建立了预见控制的车辆运动学模型。(4)基于PID控制理论设计了车辆直线行走导航控制器。通过对车辆果园直线实际行走路况的分析,采用最小二乘法拟合直线行走导航路径,以车辆的横向偏差和航向偏差为输入量设计基于PID控制理论的拖拉机果园自动直线行走比例控制器。(5)基于模糊控制理论设计了车辆曲线行走导航控制器。曲线行走时,根据车辆果园曲线路径行走的实际特点,采用二次曲线法拟合车辆曲线行走导航路径;在车辆控制方案的设计中,提出“以直代曲”实现果园曲线路径导航的思想;在曲线行走导航控制器的设计中,采用车辆前后轴中心点到路径的横向偏差作为控制系统的输入量,设计基于模糊控制理论的拖拉机果园曲线自动行走模糊控制器。(6)以VC+为开发平台,完成导航控制系统的总体设计。试验结果表明,在直线行走试验中,车辆以0.27/s的速度直线行驶50m,最大横向偏差0.15m;连续直角弯道试验中,车速0.54/s,最大横向偏差0.17m;正弦曲线行走试验中,车速0.27/s,最大横向偏差0.37m。【英文摘要】Because of the complex environmental characteristics, it is difficult to carry out mechanical automatic operations in orchard. The goal of this study is to develop the navigation system based on a laser scanner capable of navigating sprayer automatic operating in the orchard. A converted Fukuda-Oubao tractor was used as the platform. This system can navigated the tractor move automatically in straight line and curve line respectively in the simulative orchard condition. In the straight line test, a proportional controller was designed with the direction deviation and lateral deviation as input; in the curve line test, a controller based on fuzzy control was designed. The results of this study were summarized as follows:(1) Laser ranging technology was applied in fruit trees position; and a new method for fruit trees position information extraction was proposed, the method made fruit trees positioning more accurate.(2) The vehicle dynamic coordinate system was established, and the fruit trees position information scanned by the laser scanner was converted from polar form to rectangular form, the fuzzy location information in the orchard was fixed. The accurate fruit trees position information provide obstacles and path identification, navigation path planning with data support.(3) According to analysis on the actual driving experience Vehicle kinematics model based on preview control was designed in this study.(4) According to the analysis of actual road in the road, navigation path planning algorithm based on the least square algorithm was developed when the tractor move in straight line, a proportional controller based on PID theory was designed to navigate the tractor move automatically in straight line.(5) Navigation path planning algorithm based on quadratic curve was developed when the tractor move in curve line, a fuzzy controller based on fuzzy logic theory was designed to navigate the tractor move automatically in curve line, and the deviation from the front and rear wheel shafts center to the rail path was taken as input.(6) The whole design of the system was completed in“VC+”development platform. The maximum error was 15cm within 50m driving stance at the speed of 0.27m/s in the straight line test; the maximum error was 17cm in the quarter turn test; the maximum error was 35cm in the sine curve test.【关键词】激光导航 自动导航 拖拉机 果园 航向角 横向偏差 拟合路径【英文关键词】Laser navigation Automatic navigation Tractors Orchards Heading angle Lateral deviation Fitting path【目录】基于激光导航的果园拖拉机自动控制系统研究摘要6-7ABSTRACT7-8第一章 绪论11-181.1 引言111.2 研究背景11-121.2.1 精细化农业11-121.2.2 农业机械化121.2.3 人口老龄化121.3 国内外研究状况12-161.3.1 国外研究12-151.3.2 国内研究15-161.4 研究目的及意义161.5 研究内容16-18第二章 导航硬件系统18-232.1 传感器18-202.1.1 激光扫描仪182.1.2 拉线位移传感器及其标定18-202.2 方向盘控制电机及电机驱动器20-212.3 导航硬件系统工作原理21-222.4 小结22-23第三章 果树定位方法研究23-273.1 果树信息提取23-253.2 果树定位25-263.3 小结26-27第四章 果园拖拉机直线行走导航控制系统研究27-374.1 直线导航路径拟合方法27-304.2 车辆运动学模型30-324.3 仿真32-344.4 试验及结