Research On Vehicle Information Detection System In Single Loop Detector

Traffic information gathering system is the main part of intelligent transportation systems, and it is the basic tache of modern traffic management and control. At present, induce loop detection are widely used to gather traffic data. Some double loop detections are used to detect car speed information. The information that single loop detection directly providing are vehicle flow quantity and occupancy rate, it is a very high expense to change the single to double. So it is important to research on detecting vehicle speed and recognizing vehicle type by single loop detection.This paper is researching on the key technology of gathering road information- vehicle detecting system design based of single loop detection. It is mainly research on the software and hardware development of vehicle detecting system, the vehicle speed detection algorithm and vehicle type recognition algorithm based on single loop detection. Here are the main parts of contents:The paper puts forward the function demand analysis, hardware and software design framework of vehicle detecting system based on single loop detection, enables the basis of algorithm afterward. The paper ensure the system work principle based on analyzing the basic part and detection theory of loop detection, puts forward design demand of loop vehicle detection system, designs hardware framework based on MOTOROLA SCM, and analyses the function of each hardware module. Then author confirm the data type, data format, data scale and data precision of input/output data, explain the output data and output control variable of vehicle detection program, and design the program to realize function.Some researchers put forward the vehicle speed estimate algorithm utilizing single loop detection variable. But the precision is too low, and it is need earliervalidate information of vehicle length or extra addition of hardware equipments, so it is unusable. This paper puts forwards a new vehicle speed detection method based on single loop detection. This method confirms the vehicle run spot by distinguishing frequency wave inflection while vehicle running in loop, then calculates the vehicle point speed. The emulator results show that the algorithm meets the precision demand and has definite practicality.The paper researches the vehicle type recognition and sorting method using single loop detection. The ubiquitous problems of existing methods are low recognition precision, too complex algorithm and difficult to realize. The paper confirm the vehicle type information by vehicle type data gathering, sampling wave character distilling and vehicle type mode matching technology. And match the vehicle type according to the three character parameters: vehicle length, frequency change range and frequency wave crest number. The emulator results show that the project is useable and achieving upper vehicle type recognition rate. But it is necessary to distill all vehicle type characters because of the existence of various vehicle types of our country.Finally, the paper summarizes the work done, analyses the headway and puts forward the more research.