面向预期功能安全的eVTOL智能避障系统运行时保证方法  

Runtime assurance method for eVTOL intelligent obstacle avoidance system toward safety of intended functionality

作　　者：董磊[1,2] 宋文佳 陈曦[1,2] 刘嘉琛 梁博尧 DONG Lei;SONG Wenjia;CHEN Xi;LIU Jiachen;LIANG Boyao(Key Laboratory of Civil Aircraft Airworthiness Technology,Civil Aviation University of China,Tianjin 300300,China;Science and Technology Innovation Research Institute,Civil Aviation University of China,Tianjin 300300,China;Sino-European Institute of Aviation Engineering,Civil Aviation University of China,Tianjin 300300,China;College of Safety Science and Engineering,Civil Aviation University of China,Tianjin 300300,China)

机构地区：[1]中国民航大学民航航空器适航审定技术重点实验室,天津300300 [2]中国民航大学科技创新研究院,天津300300 [3]中国民航大学中欧航空工程师学院,天津300300 [4]中国民航大学安全科学与工程学院,天津300300

出　　处：《中国安全科学学报》2024年第7期105-112,共8页China Safety Science Journal

基　　金：民用航空器适航审定技术重点实验室开放基金资助(SH2023101701);中央高校基本科研业务费(3122022044);中央高效基本科研业务费(3122022QD07)。

摘　　要：为保障电动垂直起降飞行器(eVTOL)在城市空中交通(UAM)场景下的预期功能安全(SOTIF),降低人工智能算法的验证难度,建立基于运行时保证(RTA)方法的避障模型。首先,使用人工势场法改进的柔性动作评价(SAC)算法作为eVTOL智能避障系统的复杂功能;然后,使用动态反应规划(DRP)作为智能航电系统的备用功能,以减缓SOTIF危险,同时,使用监视和决策模块采集环境状态,搭建RTA架构;最后,分别仿真仅使用复杂功能和具有RTA架构的避障系统,对比避障效果。结果表明:2种方法均可实现避障,但仅使用复杂功能的传统避障系统会带来SOTIF危险;经过RTA架构设计,可使eVTOL的安全飞行时长占比由78.4%提高到98.15%,总航路长度仅增加0.95%,在保障效率的同时,降低了在运行场景中的风险。To ensure the SOTIF of eVTOL vehicles in UAM and reduce the verification difficulty of artificial intelligence algorithms,an obstacle avoidance model was proposed based on RTA method.Firstly,SAC(soft actor-critic)algorithm improved by the artificial potential field method was used as the complex function of the eVTOL intelligent obstacle avoidance system.Then,dynamic response planning(DRP)was used as a backup function of the intelligent avionics system to mitigate SOTIF hazards.Moreover,monitoring and decision-making modules were adopted to obtain environmental conditions and develop an RTA architecture.Finally,the simulated obstacle avoidance performance was compared between the two systems using complex function and RTA.The results showed that both methods can achieve obstacle avoidance,but the traditional obstacle avoidance system using complex functions may impose SOTIF risk.The RAT architecture design increased safe flight time from 78.4%to 98.15%,with the total route length only increasing by 0.95%,reducing risks in operational scenarios while ensuring efficiency.

关 键 词：预期功能安全(SOTIF) 电动垂直起降飞行器(eVTOL) 运行时保证(RTA) 城市空中交通(UAM) 智能避障系统 

分 类 号：X949[环境科学与工程—安全科学]