| Traffic congestion is a common problem faced by major cities in the world at present and in the future.The reasons for the formation are complex and diverse.The fluctuation of platoon is one of the main causes of traffic congestion of urban road.The stability control method of platoon is to improve the fluctuation of the platoon and its degree,which can effectively alleviate traffic congestion.The connected vehicle technology can realize the cooperative driving of platoon through information sharing,which can effectively alleviate the generation and spread of fluctuation of platoon.Moreover,in the future,traffic in large cities will present a state in which connected vehicels and traditional vehicles will exist in parallel for a long period.There will be some differences in the driving behavior of different types of vehicles under connected vehicle environment.Therefore,it is important to study the car following model of connected vehicle under the heterogeneous mixed traffic flow and the stability control method of platoon to alleviate the fluctuation of platoon and improve the traffic efficiency and driving safety.In this paper,the platoon control method of alleviating fluctuation under connected vehicle environment is studied.Based on the analysis of the key characteristics of connected vehicle environment,the car following model of connected vehicle is proposed.The corresponding control methods are selected from the macro and micro angles to control fluctuation of platoon.Firstly,the domestic and foreign related researches are reviewed from the aspects of the car following model and control methods.On this basis,the commonly used classic car following model and control method are introduced in detail from the theoretical methods,advantages and disadvantages and applicability.Then,Based on the analysis of the characteristics of the connected vehicle environment and its relationship with the car following behavior,the information shielding factor is introduced for the information shielding effect caused by different vehicle density.Aiming at the influence of distance loss attenuation effect on platoon information utilization,the concept of path loss is introduced.Based on GM car-following model,the environment adaptive networking(EAC)car-following model is applied.For four wave strength patterns:fast deceleration-fast acceleration(FD-FA)pattern,slow deceleration-fast acceleration(SD-FA)pattern,fast deceleration-slow acceleration(FD-SA)pattern,slow deceleration-slow acceleration(SD-SA)pattern,the difference between the EAC car-following model and the GM car-following model is studied under different connected vehicle environmental characteristic parameters:penetration rate and layout.Then,according to the analysis of the fluctuating propagation law and the critical disturbance intensity,the jam absorption control method and the variable speed limit control method are selected from the microscopic and macroscopic perspectives,and considering connected vehicle environmental characteristic parameters:penetration rate and layout,the simulation method is used to study the fluctuation mitigation effect of the above two control methods.According to the stability analysis of platoon,the simulation results show that under different fluctuation patterns,the stability of platoon of connected vehicle is higher than that of the traditional platoon.Among them,in SD-FA pattern,the speed variance is reduced by 79%,the acceleration variance is reduced by 84.2%,and the reduction is the largest.In addition,the characteristic parameters of the connected vehicle have an impact on the stability of platoon.That is,the higher the penetration rate of platoon,the lower the acceleration variance and the speed variance,and the stability of platoon increases with the increase of penetration rate;When penetration rate is the same,all connected vehicles are deployed in front of platoon,which is more stable than other layouts.For the fluctuation control of platoon,the simulation results show that under different penetration rates and layouts,the jam absorption control method and the variable speed limit control method can reduce the fluctuation and improve the stability of platoon.Among them,when penetration rate is 50%,the vehicle acceleration variance can be increased by 90%using jam absorption control method and be increased by 66%using variable speed limit control method,which proves the effectiveness of the two methods.The comparison of the two control methods shows that under penetration rate or layout,the ability of improving the stability of platoon using jam absorption control method is better than the variable speed limit control method. |
PDF Full Text Request