Eecological Trajectory Planning Of Vehicles In Urban Areas Under The Background Of Intelligent Transportation

In recent years,the rapid development of the automobile industry has brought many social problems such as energy consumption,environmental pollution and traffic congestion while providing convenience for people,which has caused a heavy burden on the green and sustainable development of cities.With the continuous development and application of intelligent transportation technology,intelligence and networking have become an important development direction of automobiles,which also provides a new way to solve the above problems.How to use the current intelligent information technology to make reasonable planning of traffic travel is the key to reducing energy consumption and alleviating traffic pressure,and is also the basis for developing sustainable transportation.Relying on the China Environmental Protection Foundation’s project "Research on Regional Traffic Energy Consumption and Pollution Analysis and Global Optimization Platform Based on Traffic Flow Big Data",this paper takes intelligent transportation as the background and based on the information of the Internet of Vehicles,and studies the energy consumption and traffic congestion of vehicles in urban areas from the two levels of path planning and speed planning.This paper aims to use intelligent information technology to give full play to the energy-saving potential of vehicles and improve the efficiency of road use.The main research contents of this paper can be summarized in the following aspects:（1）Taking single-vehicle as the research object and combining the real-world lowfrequency driving data of the vehicle,a path planning model based on energy consumption estimation is proposed.First of all,data processing is carried out for problems such as missing data and abnormal data points.Secondly,an innovative method for estimating driving energy consumption by using low-frequency data is proposed,and the driving energy consumption is estimated through two levels.In the first layer,based on the low-frequency data,the Metropolis-Hastings algorithm is used to synthesize the speed profile,which reflects the current road conditions.In the second level,with low-frequency speed profiles as the constraint,Depth-First-Search algorithm is used to obtain high-frequency speed profiles,which is used as the input to estimate the energy consumption of the road section.Finally,the top k energyconsumption optimal paths in the road network are searched for the purpose of optimal energy consumption.（2）Taking multi-vehicles as the research object,a system optimal dynamic traffic assignment model with non-vehicle holding is established.First of all,the cell transmission model is chosen as the underlying traffic flow model,and the mathematical forms of different connection combinations of cells are studied.Secondly,the reasons for the phenomenon of vehicle holding in the process of dynamic traffic assignment to multi-vehicles are further analyzed.In this paper,a method of adding penalty terms is proposed to solve the problem of vehicle holding,and the system optimal dynamic traffic assignment model with non-vehicle holding is obtained,which can assign dynamic traffic to multiple vehicles in the regional road network with the goal of the optimal system time.（3）Establish an ecological speed planning model that integrates ramp and signalized intersection scenarios,and obtain the ecological speed trajectory of the vehicle.In the case of obtaining the road information and signal timing information of the route in advance,a method of "first ramp and then intersection" is proposed to plan the ecological speed of the route.Firstly,considering only the ramp,an ecological speed planning model under the ramp scenario is designed based on the dynamic programming algorithm.The model aims at the optimal energy consumption,and globally optimizes the speed profile of the vehicle from the start point to the end point.On this basis,for the signalized intersection area,an ecological speed planning model under the signalized intersection scene is established.This model studies 7 kinds of vehicle traffic states,and designs a vehicle traffic state initial judgment strategy.Finally,an ecological speed planning algorithm under different traffic conditions is established to further optimize the speed profile.（4）The above models are simulated and analyzed to verify their feasibility and effectiveness.The simulation results show that: first of all,the single-vehicle path planning model based on energy consumption estimation can use the real-world lowfrequency data to estimate the energy consumption of the road section and find the first k optimal energy consumption paths.Secondly,the system optimal dynamic traffic assignment model with non-vehicle holding can solve the phenomenon of vehicle holding in the actual road network,accurately assign traffic flow to multi-vehicles,and give full play to the traffic performance of the road network.Finally,the ecological speed planning model that integrates ramp and signalized intersection scenarios can plan speed profiles for energy saving,effectively reduce driving energy consumption and improve the energy-saving potential of vehicles.Through the in-depth exploration of the direction of the ecological trajectory of the vehicle,this paper realizes the reasonable planning of the vehicle in terms of path and speed,and has been clearly and effectively verified by simulation experiments.The research in this paper has practical guiding significance for reducing driving energy consumption and traffic congestion,and has both economic and social benefits.