Research On Traffic State Discrimination Of Urban Trunk Road Based On Entropy And Hydrodynamics

The road traffic operating efficiency is impacted by the rapid increasing of vehicle in urban very seriously. Therefore, the study of road traffic state discrimination algorithm in order to discriminate the traffic state timely and accurate has an important theoretical and practical significance. This paper is based on non-equilibrium thermodynamics and fluid mechanics theory. This paper selects some appropriate entropy models from thermodynamic. Combining with the characteristics of road traffic system, some key parameters are selected from the traffic flow theory in order to fit the parameters of the thermodynamic entropy model. This paper establishes the road traffic system entropy model and the status discrimination algorithm which is based on entropy model.This Paper uses non-equilibrium thermodynamics entropy and hydrodynamics theory to analysis road system's association. Transportation system is a complex open system which is similar with the thermodynamic system. It also has the relevant characteristics of the non-equilibrium thermodynamics system and follows the basic discipline of thermodynamic. So, entropy can be used to describe the road transport system. This Paper uses the similarity of traffic flow and fluid to establish the concept system's comparison relationship of traffic flow and hydrodynamics. Conservation of mass, Newton's second Law and other theorems of hydrodynamics are used to analyze road vehicle flow and elicit the expression of road traffic pressure.This paper takes the basic theory of the thermodynamic entropy into the field of traffic flow and advances the theory of road traffic system entropy and dissipation structure. The value of road traffic system entropy is smaller the degree of confusion is smaller. On the other way, the value of road traffic system entropy is bigger the degree of confusion is bigger. On the basis of hydrodynamic traffic pressure, the paper selects the appropriate entropy model and the key traffic state parameter. The theory of non-equilibrium thermodynamics is used to establish the model of road traffic system entropy and the negative entropy traffic flow model. The value of road traffic state entropy and entropy production are calculated by the entropy model.The degree of traffic crowd is expressed by the value of quantificational state entropy. The effective state discrimination arithmetic is established based on entropy model. So, this paper can discriminate the state of road traffic. The negative entropy flow model can ensure the extent of traffic management and the best management time should be taken when road is crowed.This Paper takes a section of trunk road which is in the city of Harbin as the object of study. Traffic flow characteristic parameter is collected at different traffic states. Traffic system entropy model is used to discriminate traffic state. Traffic information which is collected on the road does not include occasional crowded state. In order to verify discrimination arithmetic comprehensive, the paper selects an intersection to simulate crowd state what happen once in a while. This paper uses discrimination result and real road traffic state to do regression analysis. The validity of discrimination arithmetic is verified and some advanced methods are lodged.