Active Limit Handling for Enhanced Passenger Vehicle Safety

道路交通伤害已经成为全球每年120万人死亡的主要死因，到2020年，作为主要死因(包括死亡)，道路交通伤害将上升到世界第六位。令人鼓舞的是，尽管欧洲的车辆数量在过去十年中不断增加，但死亡人数显示出缓慢的下降。这在一定程度上可以归因于通过引入被动和主动安全系统，车辆安全方面的巨大改善。然而，目前最先进的车辆安全系统绝不能被证明足以从根本上扭转清醒的交通事故统计数据。当前的主动安全系统，如电子稳定控制(ESC)，旨在限制车辆在以按需线性增加轮胎力为特征的区域内运行，远离轮胎的最大力容量，允许普通司机保持对车辆的控制。通过这个项目，我们希望探索在避免事故的情况下，使用车辆的全部可用性能而不是限制其反应的好处。我们建议开发新的控制算法，它将利用当前主动安全系统和现代动力/传动系统配置引入的控制权限，并使用专家驾驶技能来积极帮助驾驶员在紧急操纵期间开发车辆的操纵极限。米拉公司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，他们对探索采用现代动力/传动系统配置的车辆的处理能力极限以及主动安全方面的潜在好处表示了极大的兴趣。该公司已同意通过技术咨询和积极参与拟议研究任务的管理和执行来为该项目提供支持。与传统的转向、制动和动力/传动系统相比，目前的线控驱动(DBW)执行器允许显著增强对车辆的控制权限。操作员通过传统的控制装置(即方向盘、油门和刹车踏板)提供指令，而例如，ESC允许单独的车轮制动，混合动力汽车的电动马达允许单独的车轮扭矩控制。赛车手们已经开发出专家技术，使用传统的控制装置来利用轮胎的大部分可用力量。现代车辆控制系统提供的增强控制权限潜在地允许更有效地利用可用的轮胎性能。在这项工作中，我们希望探索配备DBW致动器的现代车辆的性能极限，并确定与避免事故有关的最佳运行条件。拟议工作的第一个研究任务是在车辆的操纵极限下，即在轮胎产生接近其最大容量的力的车辆运行区域内，获得稳态转弯条件。作为案例研究，我们将考虑米拉原型混合动力汽车(H4V)的动力/传动系统配置，该原型车使用两个高扭矩独立控制电机来驱动后轮。因此，我们将使用线性和非线性控制设计工具来设计控制器，这将使车辆在潜在不稳定的驾驶条件下保持稳定，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运行区域。控制设计将在高保真模拟环境中实施，使用由Mira提供的经过实验验证的车辆模型。实施战略需要检测紧急情况，并考虑到司机的意图。

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.