LIN baserad kommunikationsmodul för GPS

Sammanfattning

The work that is the basis of this Master Thesis was performed on Scania´s group of cab

development, and concerns the GPS-system in Scania´s trucks. Today, the GPS-system

consists of an active antenna mounted on the roof of the truck. The antenna is connected

to 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 requiring

GPS-information is equipped with its own antenna and receiver. This solution has been

the most cost effective to this point. Due to the fact that the number of units requiring

GPS-information increases, this solution will soon be too expensive. Multiple GPSantennas

and receivers do not only result in higher costs, it also decreases the

possibilities of further development of the cabin. Since more antennas requires

additional mounting positions, the manufacturing costs increases as well. Due to

internal 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. By

connecting 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 means

that the GPS-antenna and receiver easily can be replaced and therefore different

solutions can be evaluated. The second prototype, which is significantly smaller in size

than the first one, demonstrates a more complete product.

Further, different antenna configurations have been evaluated. Tests indicate that

sufficient result is obtained when using more cost effective antennas, compared to the

solution used today.