PECASE: A Framework for Driver Assistance in 2D Collision Avoidance Based on Lagrangian Systems

提案名称：PECASE：基于拉格朗日系统的2D防撞驾驶员辅助框架机构：斯坦福大学最近的进展，如汽车线控转向系统，雷达测距传感器和差分校正，将全球定位系统的精度提高到20厘米，为主动防撞系统铺平了道路。与试图将事故严重程度降至最低的被动约束不同，主动系统试图将车辆移出危险区域，从一开始就防止事故发生。然而，虽然主动防撞的必要组件将在几年内问世，但目前尚不清楚如何将这些组件集成到一个系统中，以平稳地辅助驾驶员，同时保证性能。该项目开发了一个碰撞避免系统框架，帮助驾驶员在二维空间中保持车道和躲避障碍物。该方法为环境中的物体指定一个危险等级，并通过协调制动和转向，在车辆上施加与危险梯度成正比的虚拟力。利用能量类比和拉格朗日动力学，可以保证辅助车辆在驾驶员控制的情况下远离障碍物。这些理论保证的发展与全尺寸测试车辆上概念的实验验证相结合。该实验设备还与车辆动力学和控制的实验室经验相结合，使本科生和研究生可以在实践中真正感受到动力学的理论概念。该项目的最终目标是展示一个理论上严谨、但在商业上可行的系统，该系统可以帮助减少每年约37,000起交通事故死亡人数，特别是40%因与固定障碍物碰撞而导致的死亡人数。该项目最初是作为职业奖资助的，并于2004年5月转换为工程师和科学家的总统早期职业奖（PECASE）奖。

Proposal Title: PECASE: A Framework for Driver Assistance in 2D Collision Avoidance Based on Lagrangian SystemsInstitution: Stanford UniversityRecent advances such as automotive steer-by-wire systems, radar ranging sensors and differential corrections that increase the accuracy of the Global Positioning System to 20 centimeters, pave the way for active collision avoidance systems. Unlike passive restraints that seek to minimize the severity of an accident, active systems seek to move the vehicle out of harm's way, preventing an accident from occurring in the first place. Yet while the necessary components for active collision avoidance will be available in a few years, it is not clear how to integrate these into a system that smoothly assists the driver while offering guaranteed performance. This project develops a framework for collision avoidance systems that assist the driver with lanekeeping and evading obstacles in two dimensions. The approach assigns a level of hazard to objects in the environment and applies a virtual force on the vehicle proportional to the gradient of this hazard through coordinated braking and steering. Using an energy analogy and Lagrangian dynamics, the assisted vehicle can be guaranteed to move away from obstacles while leaving the driver in control. Development of these theoretical guarantees is coupled with experimental validation of the concept on a full-scale test vehicle. The experimental equipment is also integrated into a laboratory experience in vehicle dynamics and control so that undergraduate and graduate students can literally feel the theoretical concepts of dynamics in practice. The ultimate objective of the project is to demonstrate a theoretically rigorous, yet commercially viable, system that can help reduce the approximately 37,000 traffic fatalities that occur each year, particularly the 40% due to collisions with fixed obstacles.This project was originally funded as a CAREER award, and was converted to a Presidential Early Career Award for Engineers and Scientists (PECASE) award in May 2004.