Research On Dynamic Control Method Of Variable Speed Limit On Expressway Based On Multi-source Data Fusion

Smart transportation is not unfamiliar to the general public.In recent years,it has received special attention and support from the state.A series of policy documents have been announced to support the development of smart transportation.Terms such as transportation power,smart highway,digital highway,and vehicle-road coordination are gradually moving toward Everyone’s vision,in the field of transportation,smart transportation has always been a key research object of transportation practitioners,experts and scholars.The construction and development of smart highways is in full swing.The operators obtain traffic flow-related data through the perception facilities of roadside facilities and upload them to The cloud realizes real-time perception of traffic status and short-term future prediction.At present,traffic flow status monitoring and discrimination mainly rely on a single data source,and the accuracy of the data needs to be improved.On the other hand,with the improvement of economic development level,highway traffic congestion is becoming more and more normalized.With the improvement of roadside variable information board management skills,variable speed limit technology has been continuously developed and applied to solve road sections.Traffic congestion problem.This article starts with the collection of traffic flow data,taking into account the lack of accuracy of a single data source,by comparing common traffic flow data acquisition methods,selecting millimeter wave radar and surveillance video as data sources,and proposing multiple sources of traffic flow data based on radar and images Data fusion algorithm to improve the accuracy of data.Combining the formation mechanism of congestion,construct a traffic congestion degree evaluation method,judge and identify the congestion nodes in the road section,and give the corresponding congestion grade division,and propose a short-term traffic flow prediction method based on LSTM according to the periodic law of traffic flow.The congestion bottleneck mainly occurs in the main line section and the confluence area.Analyze the traffic characteristics of different road sections,and study the feasibility and necessity of the implementation of variable speed limit control.For the main line section,a hierarchical speed limit control strategy is proposed.Firstly,the variable speed limit value of the bottleneck area is determined,and then combined with the driving characteristics of the vehicle,the speed is reduced from the remote end to ensure driving safety.Aiming at the confluence area,a coordinated management and control strategy for the main line and ramp is proposed,and the speed limit interval and speed limit value are determined through the congestion influence range,and the current traffic state is optimized from the perspective of the road network.Finally,an example is used to compare the changes in the traffic operation state before and after the implementation of the variable speed limit to verify the feasibility and effectiveness of the variable speed limit control strategy.