Eco-bus: Bus Pollutant Emission And Evaluation System Based On Smartphones

According to the annual report of ministry of environmental protection of2013said,Chinese vehicle emission pollutants reached46,121,000ton in2012, as the maincontributor of total amount of pollutant, the NOx and PM in vehicle exhaust surpassed15%, HC and CO surpassed84%. Motor vehicle exhaust emission is the main sourceof air pollution in our country, caused haze and smoking pollution. At present, thedevelopment of urban public transport and restricting the use of private cars become amain solution to solve traffic congestion in our country. The purpose of this thesis isto propose a quantitative description for urban bus pollutant emission levels, whichprovide decision basis for setting bus lines, scheduling bus dispatch and optimizingbus signal.In recent years, mobile sensing technology, such as applications on smartphones,has been rapidly developed. Micro sensors lead to the closely combination betweenmicro personal, vehicle dynamic and physical environment. This paper focuses on theapplication of smartphones to track bus driving behavior and the corresponding levelsof pollutant emission, which help to establish the bus pollutant emission estimationand evaluation system: Eco-bus. This paper makes some innovations which include:Firstly, applying the smartphones to get buses’ real-time speed and accelerationinformation, record bus driving behavior data under different driving cycles as buspollutant emission level is closely related to different driving behaviors. Secondly, thevehicle types of Beijing buses are quite similar, according to Vehicle-Specific Powermodels; we can establish the model to explain the relationship between bus dynamicstate and the level of pollutant emissions, which can help to evaluate how differenttraffic conditions will influence the level of pollutant emissions.Eco-bus system has completed the following tasks from the aspects of smartphoneclient designing, data acquisition and processing, computation of pollutant emissions,etc..First, with the increasing popularity and portability of smartphones, and depend ontheir various functions, we designed-an application which can used for all Androidsmartphones equipped with GPS module. This application can acquire real-timetraffic dynamic data under any time and space scales. The data can effectively reflectthe changes of bus driving behaviors in the driving process which can be used as thefoundation to estimate and evaluate the level of bus pollution emission. In addition, potential problems of data collecting are discussed, and corresponding resolutions aregiven in this paper.Secondly, in order to reduce the influence from un-eliminated error data onestimating and evaluating the results of pollutant emission, based on VSP which is amature model, a method of emissions calculation was proposed to describe the busdriving behavior during a period of time with its classification rules.Finally, this paper realized the evaluation system of the level of bus pollutantemission.It is composed of the data acquisition application for Android smartphonesand the PHP script file which is used to query evaluation result and explain it in theform of numerical and graphical. In the experiments, various bus lines around-Beijing University of Technology were chosen, a large amount of dynamic trafficdata were collected for the analysis, and the PHP (Personal Home Page) script filefinally shown the results. Through the function demonstration, it is considered that thesystem basically realizes the function of effectively estimating the levels of buspollutant emission under different driving behaviors.