基于IAHP-EWM-LDM的L3级自动驾驶接管过程安全性评价方法

A Method for Evaluating the Safety over the Takeover Process of the Level 3 Automated Vehicles Based on IAHP-EWM-LDM

在L3级自动驾驶阶段,驾驶人需要在系统发出接管请求时,及时响应并接管车辆。因此为了准确评估L3级自动驾驶车辆接管过程的安全性,构建了自动驾驶接管过程的安全性评价指标体系。本文采用4×2×2的接管场景因子设计了驾驶模拟试验,利用驾驶模拟器采集各类驾驶数据;基于变异系数法和Spearman相关性判别法从风险感知、避险操纵和接管绩效3个方面分析得到了13个安全性评价指标;使用能够表征专家经验的改进层次分析法求取指标的主观权重,使用能够反映数据特征的熵权法求取指标的客观权重;为综合2种方法的优点,利用级差最大化法获得了融合主、客观权重的综合权重,并通过计算得出风险感知、避险操纵、接管绩效的综合权重分别为0.259、0.475、0.271,以此结果来构建接管过程的安全性评价指标体系。本文运用该体系对驾驶模拟试验所获得的655个接管过程进行了综合评价,根据评价结果将其划分为A、B、C这3类接管过程。对比3类接管过程在风险感知、避险操纵、接管绩效3个方面的得分发现,A类接管过程在3个方面均表现较好,C类接管过程在避险操纵和接管绩效2个方面表现较差,B类指标的表现介于A类和C类之间,不同类别的接管过程在各个指标上均具有较好的区分度。本文构建的评价指标体系有效结合了专家经验和指标特征,能够为更加全面、合理和科学地评价自动驾驶接管过程中的安全性提供理论支持。

In the Level 3 autonomous driving stage,the driver needs to respond and take over the vehicle when the system sends a takeover request.Therefore,to accurately assess the safety of the takeover process of Level 3 autonomous vehicles,the safety evaluation index system of the takeover process of autonomous driving is constructed.In this paper,a 4×2×2 takeover scenario factor is used to design a driving simulation test,and a driving simulator is used to collect various types of driving data.Based on the coefficient of variation method and Spearman correlation discriminant method,13 security evaluation indicators are obtained from the analysis of 3 aspects,such as risk perception,risk avoidance manipulation and takeover performance.The subjective weights of the indicators are obtained using an improved hierarchical analysis that characterizes the experience of the experts,and the subjective weights of the indicators are obtained using entropy weights that reflect the characteristics of the data.To combine the advantages of the two methods,a composite weight incorporating both subjective and objective weights is obtained using the grade maximization method.The combined weights of risk perception,risk avoidance manipulation,and takeover performance are calculated to be 0.259,0.475,and 0.271,which are used to construct the security evaluation index system of the takeover process.In this paper,the system is applied to comprehensively evaluate 655 takeover processes obtained from driving simulation tests,and they are classified into 3 categories of A,B and C takeover processes according to the evaluation results.Comparing the scores of the 3 types of takeover processes in 3 aspects:risk perception,risk avoidance manipulation and takeover performance,it is found that the A-type takeover process performs well in three aspects,the C-type takeover process performs poorly in risk avoidance manipulation and takeover performance,and the B-type takeover process performs intermediary between the A-type and C-type.Different types of takeover process have a better degree of differentiation in each indicator.The indicator system is constructed that effectively combines expert experience and indicator characteristics.The evaluation index system constructed in this paper effectively combines expert experience and index characteristics.It can provide theoretical support for a more comprehensive,reasonable and scientific evaluation of the safety in the process of automatic driving takeover.