Research On Eco-Driving Strategy Of Vehicles In Urban Road Environment Based On The Cooperative Vehicle Infrastructure System

With the deepening understanding of the greenhouse effect and the non-renewable fossil fuel resources,as well as the increasing number of vehicles year by year,the traffic environment of urban roads is deteriorating.Therefore,reducing vehicle fuel consumption and exhaust emissions has increasingly become the focus of research.Unlike highways,the situation when vehicles are traveling on urban traffic networks is relatively more complicated.Due to the large number of signalized intersections in the urban traffic network,the vehicles traveling at the intersections are affected by traffic flow,traffic lights and road speed limit,and the vehicle's speed trajectory will have great fluctuations,mainly manifested in the vehicle start-up,frequent acceleration and deceleration and idling.As a result,the fuel economy will decrease and the emission of the pollutants such as CH,CO and NO_X will increase sharply,making the signalized intersection become a high energy consumption in the road network.It is obvious that the energy conservation and emission reduction work of urban road signal intersections is extremely urgent.Ecological driving(Eco-driving)behavior can effectively reduce the fuel consumption and pollutant emissions of vehicles in the urban road network,and the cooperative vehicles infrastructure system(CVIS)technology can realize real-time communication between the vehicle and the road environment.Based on this characteristic,an ecological driving strategy for vehicles driving at urban road intersections is established,thus achieving the effects of energy conservation and emission reduction while ensuring the driving safety of vehicles.On the basis of summarizing and analyzing the research on eco-driving strategy at home and abroad,this paper establishes and verifies the eco-driving strategies of urban road vehicles in environment of CVIS by using vehicle driving data that collected by real vehicle road test,actual road environment and ADVISOR simulation software,etc.The main research work carried out in this paper is as follows:1.According to the research content of this paper,the data acquisition method of the actual road test data is designed,and the representative vehicle and the accurate vehicle travel data acquisition system are selected according to the test ideas,and the test platform of real vehicle road test is built,so as to complete the collection of vehicle driving data of single signal interaction section and continuous signal interaction section of real urban road under the traditional driving environment,and obtain vehicle state information and road environment information such as speed signal,acceleration signal,displacement signal and altitude signal on the test road.The various data collected by the road experiment are post-processed,the original signal is filtered by using different digital filters,and the more suitable digital filter is selected to compare all the data by comparing the filtering effects,so as to provide accurate data support for analysis and verification of the following eco-driving strategies.2.According to the main technical parameters of the vehicle under test provided by Original equipment manufacturer(OEM),the vehicle simulation model of this type of passenger car is established by using the vehicle simulation software ADVISOR and combining with relevant theoretical formula derivation.The principle analysis is carried out on the instantaneous oil consumption model based on working conditions and the oil consumption model based on average vehicle speed.The application scope,application scenarios and their respective advantages and disadvantages of three fuel consumption models are further analyzed.The vehicle micro fuel consumption model is selected for further analysis.Combined with the actual vehicle test data,the instantaneous oil consumption model is established,thus improving the vehicle simulation model.Under the NEDC cycle condition,the built vehicle model is simulated and analyzed.The power and fuel economy are compared with the actual vehicle test data provided by the OEM to verify the correctness of the vehicle simulation model.3.Through the research on the trajectory of the vehicle under test,the status of the intersection signal and its duration collected by the actual road test,the actual urban road scene is divided into three scenarios:the initial signal light is green light,red light and yellow light according to the initial signal state.According to the duration of the signal,the green light and the red light scene are further divided into three scenarios of longer duration,shorter duration and extremely short duration.In order to concretize the research object,the basic assumptions of the eco-driving strategy are proposed.On the premise of ensuring driving safety,according to the constraint conditions under different scenes are established,and the planned trajectory of eco-driving strategies and the actual trajectory of real vehicle road tests are simulated and analyzed by using the established vehicle model.Through comparing the fuel economy,pollutant emission and driving distance of vehicles in two driving environments,the effect of the established eco-driving strategies is verified.The results show that under the same path,planning speed of eco-driving strategy can reduce the fuel consumption by more than 11.3%and emissions of CH,CO and NO_X by more than 11.3%,11.3%and 15.4%respectively.At the same time,it ensures the safety of the vehicle when driving on urban roads.