Study On Monitoring And Management System Of Highway Speed Based On GPS

With the development of social economy, highway in China develops rapidly, the highway traffic accidents happens frequently including speeding, retrograde, vehicle overloading, fatigue driving and the influence of external environment, in which speeding of the vehicles is the main reason of the traffic accidents. To monitor the behavior of vehicles’speeding in the highway, traffic administration usually use some methods of measuring velocity mainly include mobile measurement of velocity, fixed point measurement of velocity and interval measurement of velocity. All of these methods have some disadvantages, such as fixed point of measurement of velocity, as long as the drivers are familiar with the location of the measuring velocity or with the help of "electronic dog", they can easy avoid capturing of measuring system by slowing down in advance when they pass the area of the measurement of velocity. As interval measurement of velocity is to get the average speed of a fixed distance, the drivers may drive into service areas for extending driving time to escape punishment. Therefore, to design a management system of speeding which can monitor the velocity in real-time and with the whole process is of great significance, which can reduce the number of traffic accidents and improve the traffic law enforcement.In the paper, the research content is the realization of highway vehicles’velocity monitoring and management system based on GPS, and its core idea is that the GPS receiver chips installed on the motor vehicles receives and records the satellite observation data to calculate the speed information in time and location information. The speed that is matched with the vehicle location information and corresponding position of highway electronic map is compared with the speed value calculated by GPS at the same time, realizing the monitoring and management of highway speed. The paper have made the following results:1. Three sets of measured speed noise data assessment showed that the accuracy of the Doppler original observations velocity is 1.3dm/s and independent of the data sampling interval; the positions difference velocity accuracy is related to the sampling interval which is 8.1cm/s when the sampling interval is Is,and 3.5cm/s,3.2cm/s when interval become 5s or 15s; the accuracy of pseudo range and phase derived from Doppler observations velocity are both independent of the sampling interval, besides the accuracy are 4cm/s and 2cm/s respectively.2. According to the dynamic test, the position difference, pseudo-Doppler and phase-Doppler observation velocity accuracy are related to the running status of vehicles; the accuracy of the Doppler original observations velocity has nothing to do with the vehicle condition and its speed is stable. Leading speedometer into test, the statistical analysis showed that the most effective velocity methods is Doppler original observation, whose velocity results is 97.9% within the error range of the speedometer indicating speed. Then pseudo-Doppler and phase-Doppler observation velocity are followed, whose velocity results is 80% within the error range of the speedometer indicating speed; the accuracy of the position difference velocity tend to worst with only 63.2% within the error range of the speedometer indicating speed. The Doppler original observations velocity is stable and can meet highway speed monitoring accuracy of speed.3. There is a clear highway road topological relations through the analysis of highway road features. The matching method based on topology information including the vehicle position information, velocity of vehicle and highway network digital map is proposed.4. A software of highway vehicle speed monitoring and management system is designed by using the Doppler original observations velocity model and matching method of the network-topology. Furthermore, the analysis of measured data showed that it can full real-time monitor and manage the vehicle speed effectively and reliably, which test and verify the correctness of this topic.