Active Limit Handling for Enhanced Passenger Vehicle Safety

道路交通伤害已成为全球主要的死亡原因，每年造成120万人死亡，到2020年，道路交通伤害将上升到世界第六位，成为主要的死亡原因（包括死亡）。令人鼓舞的是，尽管在过去十年中欧洲的车辆数量不断增加，但死亡人数显示出缓慢下降的趋势。这可以部分归因于通过引入被动和主动安全系统，车辆安全性得到了巨大改善。然而，目前最先进的车辆安全系统绝不能证明足以从根本上扭转清醒的交通事故统计数据。目前的主动安全系统，如电子稳定控制系统（ESC），旨在限制车辆在一个区域内的操作，该区域的特征是轮胎力的按需线性增加，远离轮胎的最大力容量，允许普通驾驶员保持对车辆的控制。通过这个项目，我们希望探索在避免事故的情况下，利用车辆的整个可用性能而不是限制其响应的好处。我们建议开发新的控制算法，这将使用当前的主动安全系统和现代动力/传动系统配置引入的控制权限，并采用专家驾驶技能，积极协助驾驶员在紧急操纵过程中利用车辆的处理限制。MIRA是世界领先的汽车产品工程、测试、认证和研究的独立供应商之一，他们对探索具有现代动力/传动系统配置的车辆的处理能力极限以及主动安全的潜在优势表示了极大的兴趣。该公司同意通过技术咨询和积极参与管理和执行拟议的研究任务的方式为该项目提供支持。与传统的转向，制动和动力/传动系统相比，当前的线控（DBW）执行器可以大大增强对车辆的控制权限。人类操作员通过常规控制装置（即方向盘、油门和制动踏板）提供命令，而例如ESC允许单独的车轮制动，并且混合动力车辆中的电动机允许单独的车轮扭矩控制。赛车手已经开发出专业的技术，利用传统的控制来利用轮胎的大部分可用力。由现代车辆控制装置提供的增强的控制权限潜在地允许甚至更有效地使用可用的轮胎性能。在这项工作中，我们希望探索现代车辆的性能极限配备DBW执行器，并确定最佳的操作条件，避免事故。拟议工作的第一项研究任务是获得车辆操纵极限下的稳态转弯条件，即在轮胎产生接近其最大能力的力的车辆操作区域中。作为一个案例研究，我们将考虑MIRA的原型混合动力车（H4 V）的动力/传动系统配置，它使用两个高扭矩独立控制的电动机来驱动后轮。因此，我们将使用线性和非线性控制设计工具设计控制器，这将使车辆在潜在的不稳定驾驶条件下稳定，而不是使用DBW控制输入将车辆限制在远离其性能限制的稳定操作区域。控制设计将采用MIRA提供的经过实验验证的车辆模型，在高保真仿真环境中实施。实施策略需要检测紧急情况并考虑驾驶员的意图。

Road traffic injuries have become a leading cause of death globally accounting for 1.2 million deaths annually, and will rise in worldwide rank to sixth place as a major cause of death (including decease), by 2020. It is encouraging that, despite the constant increase of the number of vehicles in Europe during the last decade, the number of fatalities demonstrates a slow decay. This can be partly attributed to the enormous improvements in vehicle safety, through the introduction of both passive and active safety systems. By no means, however, have the current state-of-the-art of vehicle safety systems proven adequate to radically reverse the sober traffic accident statistics.Current active safety systems, such as the Electronic Stability Control (ESC), aim at restricting the operation of the vehicle within a region characterised by an on-demand linear increase of tyre forces, away from the tyre's maximum force capacity, allowing the average driver to maintain control of the vehicle. With this project we wish to explore the benefits of using the whole of the available performance of the vehicle, rather than restricting its response, in accident avoidance situations. We propose the development of novel control algorithms, which will use the control authority introduced by current active safety systems and modern power/drive-train configurations, and employ expert driving skills to actively assist the driver exploit the limits of handling of the vehicle during emergency manoeuvring. MIRA, one of the world's leading independent providers of vehicle product engineering, testing, certification and research, has expressed their great interest in exploring the limits of the handling capacity of vehicles with modern power/drive-train configurations and the potential benefits in active safety. The company has agreed to offer their support to this project by means of technical consultation and active participation in the management and execution of the proposed research tasks.Current drive-by-wire (DBW) actuators have allowed for a considerably enhanced control authority over the vehicle, as compared to traditional steering, brake and power/drive-train systems. The human operator provides commands through the conventional controls, that is, the steering wheel, and the throttle and brake pedals, whereas, for instance, the ESC allows for individual wheel braking, and electric motors in hybrid vehicles allow for individual wheel torque control. Race drivers have developed expert techniques to exploit most of the available force capacity of the tyres using the traditional controls. The enhanced control authority provided by modern vehicle controls potentially allows for even more efficient use of the available tyre performance. In this work we wish to explore the performance limits of modern vehicles equipped with DBW actuators, and identify optimum operating conditions related to accident avoidance. The first research task of the proposed work is to obtain steady-state cornering conditions at the limit of handling of the vehicle, that is, in a region of vehicle operation where the tyres produce forces close to their maximum capacity. As a case study we will consider the power/drive-train configuration of MIRA's prototype hybrid vehicle (H4V) which uses two high-torque independently controlled electric motors to drive the rear wheels. Consequently, we will design controllers using linear and nonlinear control design tools, which will stabilise the vehicle in potentially unstable driving conditions, instead of restricting the vehicle in a stable operating region away from its performance limits, using DBW control inputs. The control design will be implemented in a high fidelity simulation environment using experimentally validated vehicle models provided by MIRA. The implementation strategy entails the detection of emergency situations and accounts for the driver's intention.