Study On Speed Prediction Model Of Trucks Based On VSP For Mountainous Highway

To establish the model of vehicle fuel consumption,we need to predict the speed of vehicle.However,the current vehicle speed prediction models were used to ameliorate the design of road alignment,and the prediction speed of those models is the isolated speed,and the design thoughts did not consider the restraint of driver’s behavior characteristics.Thus,these current speed prediction models did not adapt the fuel consumption predicting.Therefore,to accurately reflect the fuel consumption,the vehicle speed prediction model is the first step.Firstly,this paper introduced the origin and the objective of the truck speed model of mountainous highway,and studied the feasibility of the way of VSP(Vehicle Specific Power).Then analyzed the speed control patterns of different types of road.Then obtained the VSP mathematical formula and demarcate the unknown parameters by establishing the truck uphill dynamical model,and analyzed the control modes of truck driving on different types of roads.Next,obtained the steady speed in crooked road by established the vehicle dynamical model based on vehicle dynamics,and used them to revise the truck speed prediction model established below.Secondly,carried out the vehicle test and collected some relevant data by Weichai smart CAN line and video acquisition instrument.Then,classified the type of road by data pee-processing,and screened the free stream data.Next,obtained the characteristics of VSP in different type of roads by data post-processing.And found that the truck speed and acceleration showed some regularities in different distribution internals,and found that different factors showed different degrees of influence.Then,established the truck uphill speed prediction model by using the discovered regularity,and established the truck downhill speed prediction model by multivariable regression fitting method.Finally,the truck speed prediction model is verified through a goodness of fit testing approach by using the sample data collected from the mountainous highway road which of the data was not used to establish the speed prediction model of trucks for mountainous freeways.The results showed that the relative error between the predictive value and the real value of the truck speed is less than 8%,and the relative error between predictive value of operating speed of the JTG B05-2015 issued by ministry of Communications and the real value of truck speed is above 15%,which verifies the reliability and effectiveness of truck speed prediction model for heavy truck of mountainous highway.According to the conclusion,thought and formulas established above,this paper programmed the truck speed prediction of highways system based on the platform of Visual C++ to make it more intuitive.