Vehicle Platoon And Signal Optimized Control Method For Highway Section Within Low Visibility Zone

In recent years,due to the increasing attention to traffic safety,the traffic accident rate in China has been declining year by year.However,the traffic accident rate is still at a high level in bad weather conditions,especially in low-visibility conditions.In the low-visibility section of ordinary highway,the driver has a shorter visibility distance.Thus traffic accidents are prone to occur when vehicles pass through this section at speeds with large speed difference.In order to improve traffic safety,rely on the project of National Natural Science Foundation of China "Risk Assessment and Safety Design Parameters Optimization of Highway Traffic Flow Accidents under Visibility Impact"(No.51578207),this paper proposes a platoon control method,which makes traffic flow enter the low-visibility section safely in the form of platoon through signal intersection control.Bad weather not only affects traffic safety,but also has a negative impact on operational efficiency,therefore,combined with speed guidance and actuated control,this paper further proposes a comprehensive optimization control method for multi-intersection highway sections.The main research contents are as follows:(1)Study the traffic flow characteristics under low visibility,determine the influencing factors of speed parameters,and propose the speed model and speed range selection method of platooning control.(2)According to the road characteristics of the major-minor intersection in the upper reaches of the low-visibility area,a platoon control method is proposed,the partition process involved is explained and scenario assumptions are put forward.Then the guidance and control process of single-lane and two-lane scenarios are elaborated respectively,and the setting methods of platoon time,dissipation time and other parameters in the control method are determined.The effectiveness and applicability of the control method in improving traffic safety are verified by simulation experiments.(3)When there are intersections in low-visibility area,based on the basic platoon control and consider the characteristics of the vehicle platoon,an optimal control method is proposed to reduce the control delay at signalized intersections.Firstly,the method of determining the critical distance of the platoon is proposed.Secondly,the two stages of speed guidance and signal actuated control of the optimization method are elaborated in detail.Finally,case simulation is carried out to verify the effectiveness of the optimal control method in reducing delay by analyzing the delay from the major and minor directions of intersections.