The Design And Implementation Of A Locating, Tracking And Dispatching System Based On GPS

For these years, the GPS (global positioning system) technique has been used in civil area. This technique was used in army before. By this technique, people can easily locate and track the target; furthermore send commands to the target. But the GPS data is a basic material; just by GPS data ,people cannot enjoy a friendly service. How to design a locating, tracking and dispatching system based on GPS technique? This is a complex project but also the goal of this article.Locating feature is the basic requirement of a locating, tracking and dispatching system. It includes showing the current address and history address. It means the system should store much GPS data of the target. Also this is a real time service. So the system should have power operation capability. Base on the locating feature we can develop many valuable services like speeding alert, stop alert, geofence alert and finding the closest target by a given address. Since we can know the address and time of the target, we can dispatch the target with high precision.This article analyses and designs a high performance hash file store system to store GPS data. It has four times write speed and more than one time read speed comparing to Oracle database. It implements a mechanism, which lets two machines backup each other. Also it has the ability to extend to a cluster. The store system adopts some new techniques like nonblocking IO, thread pool, task queue and so on. We also design an alert server to calculate the alert. This sub system includes a primary and a slave server. We also design a RGC server, which adopts map partition technique to cache the address. We also design a mileage server. At last we successfully merge these several servers (GPS data relative) to one server. This article analyses and designs a web sub system and a web service sub system. In web sub system it adopts AJAX (asynchronous JavaScript and XML) technique to improve user experience. In web service sub system the article focuses on how to use Axis to quickly expose the function to a web service .At the end, the article emphasizes how to test the system and analyses the test result, it analyses the performance issue of sub systems and gives improving solutions.