GPS BASED DATA ACQUISITION SYSTEM FOR MOBILE APPLICATIONS

Abstract

The Global Navigation Satellite Systems allow an accurate determination of the position in a geocentric reference system, using the signals from the artificial satellites network, received with dedicated devices. The GPS devices are well known and used by many people, especially for navigation. These are commercial GPS devices, which can be found at decent prices. Professional devices also exist for geodesic applications, and even for dynamic data acquisition. These are much more precise devices, but more expensive. This paper presents an acquisition system developed by the authors, using a high performance GPS device, available on the market, a portable mini-computer and dedicated software. The GPS sensor is one oriented to OEM users, for machine operation and guiding and agricultural applications. The sensitivity is very high and the registration rate is 5 Hz. It is connected to a computer through serial interface. The software application developed for this system takes the information from the GPS sensor using the sentences defined by the NMEA messages standard. Information about position, velocity and acceleration are displayed in real time on the computer screen and all useful data acquired are saved in a text file. These data are imported then in a special CAD application, for post-processing. The system was used in various studies regarding vehicle dynamics or efficiency and in traffic or noise analysis.