高速公路合流区主要参数对自动驾驶车辆的影响

为探究现有高速公路合流区对自动驾驶车辆的适应性,分析现有高速公路合流区加速车道长度和通视三角区角度对自动驾驶交通流的影响规律,并与传统交通流进行对比。依据自动驾驶车辆在感知、跟驰和换道行为以及与周围车辆的协作方面更迅速安全等特点,改进了Krauss跟驰模型和LC2013换道模型以适应自动驾驶车辆特征。依据车辆换道可接受间隙建立车辆跟驰间距计算公式,在满足换道安全的基础上对跟驰模型参数进行改进。结果表明:在现有的高速公路合流区平面设计参数条件下,自动驾驶交通流的安全性、效率及稳定性均优于传统交通流,与传统交通流相比,自动驾驶交通流冲突数减少了100%,平均延误降低了60%～71%,平均车速提高了近20%且更稳定；在不同平面设计参数下,自动驾驶车辆的冲突数均为0,平均延误保持在0.65 s左右,平均车速稳定在33～34 m/s。现有的高速公路合流区平面设计参数在安全、效率和稳定性方面均能较好地适应自动驾驶车辆,且参数的取值对自动驾驶车辆影响不大。

Impact of main parameters of merging area in highway on autonomous vehicles

In order to explore the adaptability of the existing merging area in highway to autonomous vehicles, the influence of the acceleration lane length and the visibility triangle angle of existing highway merging area on the automatic traffic flow was analyzed, and results were compared with those of traditional traffic flow. Based on the characteristics of autonomous vehicles in terms of perception, car-following, and lane-changing behaviors, as well as the collaboration with surrounding vehicles, the Krauss car-following model and LC2013 lane-changing model were improved to adapt to the characteristics of autonomous vehicles. According to the lane-changing characteristics of the vehicles, a formula was established for calculating the acceptable safety gap when changing lanes, and the car-following model parameters were adjusted while fulfilling the requirement of lane-changing safety. Results show that under the existing plane design parameters of merging area in highway, the safety, efficiency, and stability of automatic traffic flow were better than those of traditional traffic flow. Compared with traditional vehicles, the number of collisions of automatic traffic flow reduced by nearly 100%, average delay reduced by 60% to 71%, average vehicle speed increased by nearly 20%, and the speed was more stable. Under different plane design parameters of merging area, the number of collisions of automatic traffic flow was 0, the average delay was maintained at around 0.65 s, and the average speed was stable at 33-34 m/s. The existing plane design parameters of merging area in highway well adapted to the autonomous vehicles in terms of safety, efficiency, and stability, and the parameter values of the merging area had little effect on the autonomous vehicles.