LIN baserad kommunikationsmodul för GPS
The work that is the basis of this Master Thesis was performed on Scania´s group of cabdevelopment, and concerns the GPS-system in Scania´s trucks. Today, the GPS-systemconsists of an active antenna mounted on the roof of the truck. The antenna is connectedto the receiver with a coaxial cable.The purpose with this Master Thesis was to develop and evaluate a new GPS-system,where the information is distributed using a LIN-network. Today, each unit requiringGPS-information is equipped with its own antenna and receiver. This solution has beenthe most cost effective to this point. Due to the fact that the number of units requiringGPS-information increases, this solution will soon be too expensive. Multiple GPSantennasand receivers do not only result in higher costs, it also decreases thepossibilities of further development of the cabin. Since more antennas requiresadditional mounting positions, the manufacturing costs increases as well. Due tointernal losses, the use of coaxial cables put high demands on antennas and receivers,which also increases system costs.The concept developed in this thesis only requires one GPS-antenna and receiver. Byconnecting the GPS-module to a microcontroller that in turn is connected to a network,the information is available for all connected sub systems in the vehicle.Two prototypes have been developed. The first prototype is module based. This meansthat the GPS-antenna and receiver easily can be replaced and therefore differentsolutions can be evaluated. The second prototype, which is significantly smaller in sizethan the first one, demonstrates a more complete product.Further, different antenna configurations have been evaluated. Tests indicate thatsufficient result is obtained when using more cost effective antennas, compared to thesolution used today.