Experimental Study On Vehicle Following Behavior Simulation

With the rapid development of intelligent transportation,people's research on micro-traffic flow theory is more and more detailed,and the vehicle-following model is developed with the development of micro-traffic flow theory.As the basis of the micro-traffic flow theory,vehicle-following model plays an important role in the improvement and supplement of traffic flow theory.It is of great significance to analyze and study the traffic safety,traffic management and road capacity assessment.Therefore,it is of great theoretical and practical value to study the car-following model.However,most of the existing research methods are based on mathematical analysis and lack of a real and intuitive display platform.For this purpose,the paper develops a vehicle-following behavior simulation test platform with demonstration function based on the Single-Board RIO unmanned vehicle hardware platform of NI company.First of all,on the basis of reading a large number of professional documents,review the research topic in detail.Since the Optimal Velocity Following Model is structurally simple,mathematically easy to be expanded and widely used,it is taken as the key research object and compared with the Full Velocity Difference Model.Second,the Optimal Velocity Model and the Full Velocity Difference Model are calibrated based on the performance of unmanned vehicle.The stability of the calibrated Vehicle Following Model is analyzed by using the linear stability theory.The exact condition of stability of the model is calculated by using cybernetics and mathematical analysis method.And the stability of the calibrated vehicle following model is theoretically verified by using C++ and MATLAB programming techniques.What's more,three sets of vehicle following experiments are designed to verify the stability of the model.The main works are as followed.To do advanced development of NI Single-Board RIO embedded control board.Based on its on-board hardware interface,extend the RS232 serial port to WiFi module,complete the hardware debugging and software design of the communication module which realized the communication of unmanned vehicle with computer and the communication between following vehicle and the leading vehicle.Extend the infrared sensor module,design the tracking runway and program of the slave machine's movement,realize the tracking function of unmanned vehicle.Lastly,the upper computer interface is designed by using LabVIEW language,the data of the unmanned vehicle's movement is collected,processed,saved and displayed in real time,including the distance between the following and leading vehicle,their speed,acceleration of the following vehicle and other information.The innovation of this paper lies in the organism combination of the tracking and following behaviors.And the vehicle following behavior of a two-cars system on a single track is demonstrated accurately.In the experimental process,the wireless communication is realized by using WiFi technology.And according to the functional requirements,the front and rear cars can obtain real-time motion information of each other,such as velocity change,acceleration change and vehicle spacing and other informations.It realized information interaction which embodies the idea of vehicle networking and conforms to the trend of future traffic development.A man-machine interface for displaying vehicle motion state information is developed in this paper,which is convenient for data observation,analysis and processing,and provides reference for researchers to study vehicle following behaviors in the future.