Automatic Steering Methods for Autonomous
Automobile Path Tracking
Jarrod M. Snider
CMU-RI-TR-09-08
February 2009
Robotics Institute
Carnegie Mellon University
Pittsburgh, Pennsylvania
c Carnegie Mellon University
Abstract
This research derives, implements, tunes and compares selected path tracking methods for controlling a car-like robot along a predetermined path. The scope includes commonly used methods found in practice as well as some theoretical methods found in various literature from other areas of research. This work reviews literature and identifies important path tracking models and control algorithms from the vast background and resources. This paper augments the literature with a comprehensive collection of important path tracking ideas, a guide to their implementations and, most importantly, an independent and realistic comparison of the performance of these various approaches. This document does not catalog all of the work in vehicle modeling and control; only a selection that is perceived to be important ideas when considering practical system identification, ease of implementation/tuning and computational efficiency. There are several other methods that meet this criteria, however they are deemed similar to one or more of the approaches presented and are not included. The performance results, analysis and comparison of tracking methods ultimately reveal that none of the approaches work well in all applications and that they have some complementary characteristics. These complementary characteristics lead to an idea that a combination of methods may be useful for more general applications. Additionally, applications for which the methods in this paper do not provide adequate solutions are identified.
Acknowledgements
This work would not have been possible without the support, motivation and encouragement of Dr. Chris Urmson, under whose supervision I chose this area of research. I would like to acknowledge the advice and guidance of Dr. William ”Red” Whittaker, whom never ceases to amaze and inspire me. Special thanks go to Tugrul Galatali, whose knowledge and assistance was instrumental in the success of this research and paper.
I acknowledge Mechanical Simulation for their generous support and discount of CarSim. Without CarSim, quality analysis and comparison of tracking methods may not have been possible.
I would also like to thank the members of my family, especially my wife, Amy, and my son Xavier for supporting and encouraging me in everything I do.
Contents
1 Introduction 1
1.1 Experimental Design 3
1.1.1 Lane Change Course 3
1.1.2 Figure Eight Course 4
1.1.3 Road Course 5
2 Geometric Path Tracking 8
2.1 Geometric Vehicle Model 8
2.2 Pure Pursuit 9
2.2.1 Tuning the Pure Pursuit Controller 10
2.3 Stanley Method 14
2.3.1 Tuning the Stanley Controller 15
3 Path Tracking Using a Kinematic Model 18
3.1 Kinematic Bicycle Model 18
3.1.1 Path Coordinates 20
3.2 Kinematic Controller 21
3.2.1 Chained Form 22
3.2.2 Smooth Time-Varying Feedback Control 23
3.2.3 Input Scaling 24
3.2.4 Tuning the Kinematic Controller 25
4 Path Tracking Control Using a Dynamic Model 28
4.1 Dynamic Vehicle Model 29
4.1.1 Linearized Dynamic Bicycle Model 30
4.1.2 Path Coordinates 31
4.1.3 Model Parameter Identification 33
4.2 Optimal Control 36
4.2.1 Tuning the Optimal Controller 38
4.3 Optimal Control with Feed Forward Term 41
4.3.1 Tuning the Optimal Controller with Feed Forward Term 44
4.4 Optimal Preview Control 46
4.4.1 Tuning the Optimal Preview Controller 49
5 Performance Comparison 61
5.1 Tracking Results 61
6 Conclusions and Future Work 65
List of Figures
|
1 Sandstorm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
|
1
|
|
2 Stanley . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
|
1
|
|
3 Boss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
|
1
|
|
4 Screen shot from a CarSim animation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
|
3
|
|
5 Lane Change Course . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
|
4
|
|
6 Figure Eight Course . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
|
5
|
|
7 Road Course . . . . . . . . . . . . . . . . . . . . . . . . .
剩余内容已隐藏，支付完成后下载完整资料
自主汽车路径追踪的自动转向方法
摘 要
这项研究的得出，是通过落实，调整和比较了用于沿着预定路径控制类似汽车的机器人的所选路径跟踪方法，范围包括实践中发现的常用方法以及其他研究领域的各种文献中发现的一些理论方法。这项工作回顾了文献，并从广阔的背景和资源中确定了重要的路径跟踪模型和控制算法。本文通过全面收集重要的路径跟踪思想，以及它们的实现方式，最重要的是，对这些不同方法的性能进行独立和客观的比较，来丰富文献。本文档未对车辆建模和控制中的所有工作进行分类。在考虑实际系统识别、易于实现/调整和计算效率时，只选择一个被认为重要的思想。还有其他几种符合此标准的方法，但是它们都与所介绍的一种或多种方法相似，因此不包括在内。跟踪这种方法的性能和结果，进行分析和比较，最终表明，这些方法都不能在所有应用程序中很好地工作，并且它们具有一些互补的特性。这些互补的特征引出了一种想法，即方法的组合对于更一般的应用可能有用。此外，确定了那些用本文中的方法无法提供解决方案的应用程序。
致谢
没有克里斯·厄姆森博士的支持，激励和鼓励，这项工作是不可能完成的，我在他的监督下选择了这一研究领域。我想感谢William Red Whittaker博士的建议和指导，他一直给我带来惊喜和启发。特别感谢Tugrul Galatali，他的知识和帮助对这项研究和论文的成功至关重要。
我感谢Mechanical Simulation对CarSim的大力支持和优惠。没有CarSim，很可能无法进行质量分析和跟踪方法的比较。
我还要感谢我的家人，尤其是我的妻子艾米（Amy）和我的儿子泽维尔（Xavier）在我所做的一切工作中对我的支持和鼓励。
目录
1 简介 1
1.1 实验设计 3
1.1.1 车道变换课题 3
1.1.2 八字形轨迹课题 4
1.1.3 公路课题 5
2 几何轨迹追踪 7
2.1 几何车辆模型 8
2.2 理论追踪 9
2.2.1 调整理论追踪控制器 10
2.3 斯坦利模型 14
2.3.1 调整斯坦利控制器 14
3 运动模型的轨迹跟踪 17
3.1 运动自行车模型 18
3.1.1 轨迹坐标 20
3.2 运动控制器 21
3.2.1 链式控制 21
3.2.2 平滑的时变反馈控制 22
3.2.3 输入缩放控制 23
3.2.4 调整运动控制器 25
4 使用动态模型的轨迹跟踪控制 28
4.1 动态车辆模型 29
4.1.1 自行车线性化动态模型 30
4.1.2 轨迹坐标 31
4.1.3 参数识别模型 32
4.2 优化控制 36
4.2.1 调整最佳控制器 38
4.3 具有正反馈的最优控制 41
4.3.1 使用正反馈调整最优控制器 43
4.4 最佳预览控制 46
4.4.1 调整最佳预览控制器 49
5 性能比较 61
5.1 结果追踪 61
6 结论与展望 66
图片清单
|
1 沙尘暴........................................................................................................................................................
|
1
|
|
2 史丹利hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;...hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;
|
1
|
|
3 老板..............................................................................................................................................................
|
1
|
|
4 CarSim动画的屏幕截图 hellip;hellip;hellip;hellip;.hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;
|
3
|
|
5 换道课题 hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;
|
4
|
|
6 八字形课题hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;....................................................................................
|
5
|
|
7 道路课题.....................................................................................................................................................
|
6
|
|
8 公路速度曲线剖面.................................................................................................................................
|
7
|
|
9 几何自行车模型......................................................................................................................................
|
8
|
|
10 理论几何模型hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;...
|
9
|
|
11 在变道过程中不同速度和增益的理论追踪hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;.
|
11
|
|
12 在八字形模型中以不同速度和增益追踪hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;..........................
|
12
|
|
13 道路模型中以不同速度和增益追踪hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;
|
13
|
|
14 斯坦利法几何模型.................................................................................................................................
|
14
|
|
15 斯坦利控制器在多种速度和增益下实现变道hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;
|
15
|
|
16 Stanley控制器以多种速度和增益在八字形轨迹上运动hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;
|
16
|
|
17 Stanley控制器以多种速度曲线和增益在公路上行驶hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;..
|
17
|
|
18 自行车运动学模型.............................................................................................................................................
|
18
|
|
19 轨迹坐标下的自行车运动学模型............................................................................................................
|
21
|
|
20 在变道过程中具有多种速度和增益的运动控制器.........................................................................
|
26
|
|
21 在八字形模型上具有多种速度和不同增益的运动控制器........................................................
|
27
|
|
22 在公路模型中具有多种速度和增益的运动控制器hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;
|
28
|
|
23 动态自行车模型 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;hellip;.
|
29
|
|
24 轨迹坐标下的自行车动态模型.................................................................................................................
|
31
|
|
25 轮胎横向力数据示例图............................................
剩余内容已隐藏，支付完成后下载完整资料
资料编号：[238007]，资料为PDF文档或Word文档，PDF文档可免费转换为Word
|
|
