Investigation To Driving Cycle And Fuel Consumption Of Sedan In Xi’an Urban Traffic Environment

Along with expansion of urban population and scale, most domestic cities are facingwith huge traffic problem. Alleviating traffic congestion, reducing traffic energy consumptionand environmental pollution, ensuring traffic safety are three hot issues to be resolved intraffic field. Among them, urban traffic energy has become a key factor which would decidethe city function could operate properly and residents living standards could improve. Trafficenergy consumption in urban is a complicated problem, which is related to not only vehicleperformance, but also road conditions, traffic information, evaluation methods etc. Especiallyin large and medium-sized cities which have different city structure and traffic condition, it isso significant to study vehicle’s virtual operating condition and fuel consumption features intypical urban for reducing fuel consumption and environmental pollution of transport system.Therefore, this paper, represented by Xi’an city, will focus on energy consumption ofmedium-sized city with typical structure and study the vehicle’s virtual driving condition andfuel consumption characteristics in urban traffic, which will be used to reduce traffic energyconsumption and to achieve the sustainable development of urban traffic from the vehicleoperating view. Evaluation methods for driving cycle including validity, pollutantidentification and operation feasibility will be put forward and constructed Xi’an driving cyclewould be evaluated.The paper first analyzes calculation method and influence factors of vehicle fueleconomy based on field test. Furthermore "economical driving mode" is explored to reducevehicle’s operating fuel consumption and exhaust emission. Under structure analysis andtraffic investigation of Xi’an city, road test program has designed in detail based on statisticaltheory, which including in-vehicle data acquisition system, method, route, vehicle, driver andsampling interval etc. The rough data including speed, fuel consumption and traffic flow inXi’an urban road will be obtained through road test. Then features of Xi’an urban road trafficare analyzed so that characteristic parameters reflecting the vehicle’s driving cycle areextracted and their mathematical models were established. Based on this, original test data areresolved and reconstructed by use of wavelet transform firstly, characteristic parameters areanalyzed by use of principal component analysis, factor analysis and clustering method, and driving cycle of Xi’an city has established through combining method of short trip andclassification. Finally, driving cycle about Xi’an urban road traffic is proved and contrastedwith foreign standard driving cycles.On the basis of original test data, the paper analyses vehicle’s fuel consumptioncharacteristics thoroughly, and establishes the microscopic theoretical model about vehicle’sfuel consumption and macroscopic forecasting model about fuel consumption of urban roadtraffic. Microscopic theoretical model, clustered of factors affecting fuel consumption, isestablished by multivariate regression theory and can be used to analyze actual fuelconsumption pattern under different road condition. Macroeconomic model is established onthe factor which has best correlation with fuel consumption and traffic flow status. Combinedwith traffic flow, macroeconomic model can be used to predict fuel consumption level ofvarious road sections and intersections, and even the total fuel consumption of urbantransportation network. At last, test vehicle’s simulation model and Xi’an urban simulationdriving cycle are established on ADVISOR platform, and simulation fuel consumption dataare obtained while simulated vehicle operating according to established simulation drivingcycle. By comparing of simulated data, original test data and model forecast data, feasibilityand effectiveness of using simulation platform to evaluate vehicle’s fuel consumption in urbantraffic environment would be analyzed.