| With the continuous improvement of people’s living standard, car ownership is growing at an unprecedented rate in our country, the problems of traffic energy shortage and environmental pollution are becoming more and more seriously, and the construction of city traffic system of energy conservation, environmental protection, low carbon and sustainable development is becoming more and more exigent.Driving conditions of vehicle has a direct effect on the car fuel consumption. City car emissions can be effectively controlled and the pollution of atmosphere can be reduced by droping the fuel consumption. Due to the characteristics of the urban car driving conditions, the scale and quality of road construction in China, and so on, has obvious difference from Europe, completely copying European ECE cycle does not conform to the actual situation of our country, thus, the study of driving cycle based on the characteristic of urban road traffic conditions suitable for our country has practical significance. In addition, when car brakes under different driving cycles, massive energy is not entirely used, and energy utilization of the cars is reduced. How to reasonably use the consumed energy and reduce energy consumption is also the way to solve the energy using problem. In view of this problem, taking Harbin as research object and according to its climate characteristics, driving conditions of different seasonsand road types was built and the energy use of all kinds of driving cycles was evaluated trying to find the ways to reduce energy consumption of the urban traffic from the angle of view of the energy utilization for driving conditions to realize the sustainable development of urban traffic.In this paper, automobile driving and braking process was analyzed, the concepts of working condition of sliding, energy consumption, energy state and energy utilization were put forward. Energy efficiency model was built according to the principle of energy balance. The sliding time and distance about different braking original speed were gained at the working condition of ECE by applying the bench test. Braking energy utilization rate is less than 30% through evaluating the energy using situation of ECE working condition. Fuel economy test has been done using ECE performance curve and ECE sliding performance curve by establishing the ECE cycle data table of sliding conditions and analyzing two indicators of the fuel consumption of per 100km and the average speed. Results show that ECE sliding condition is less than the ECE conditions in the aspect of energy saving, which the average speed is improved by 12%, and the fuel consumption of per 100km is reduced by 25%.Data acquisition system has been set up by using on-board real-time monitoring and secondary development technology. From the test process design, test method, test section, test time, test vehicle and driving requirement and so on, the test data collection scheme of the car condition has been compiled in detail.200000 valid data of driving working conditions were collected on selected test route according to summer and winter. By applying MATLAB software to compile programs, the road test raw data were divided by 1223 short strokes, and the characteristic value for the single short stroke and the whole data were calculated. Using principal component analysis and cluster analysis method, through the comparison of the proportion of short stroke number, operation time and operation mode time for the different classification, the whole sample for short stroke of summer and winter is divided into four categories in order to study Harbin roads conditions. Analyzing the working characteristics of different seasons in Harbin, results shows that the average speed of the car on the road has big difference, it is 26.1km/h in summer, and 19.53km/h in winter.The selected schemes of construction characteristic value of all kinds driving modes were determined in summer and winter according to the different road conditions and different seasons in the paper. Roads types which are including express way, arterial road, sub-arterial road, branch road, and comprehensive condition were constructed in different seasons in Harbin from all kinds of short trip database, and the error analysis was also made. Drawing speed-acceleration joint distribution figure respectively of all kinds of driving conditions, results showed that the trend of the curve is similar. Moreover, comprehensive running condition in Harbin was compared in home and abroad.Transient conditions of various road types in the different seasons were dealt with into modal conditions by using wavelet de-noising method. After setting up reducing speed condition tables of all kinds of working conditions, the gliding speed range was determined in order to calculate energy utilization rate. Through bench test, getting the sliding time and distance of all kinds of modal working condition at different braking original speed, and making the calculation and evaluation to the energy utilization ratio at different seasons and different road types, results show that different seasons and road types have certain influence on energy utilization rate. Establishing comprehensive sliding condition cycle data table according to sliding time at different braking original speed in summer and winter, and using modal condition curve and sliding conditions curve, fuel economy on the bench test has been done. Analyzing the test results by the two indices of fuel consumption per 100km and the average speed, results show that the energy saving effect is different fromsliding condition of different seasons. |
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