GF82.61-P-2002QMJ Continuous Position Finding, Function

GF82.61-P-2002QMJ Continuous Position Finding, Function
- with CODE (498) Japan version


Continuous position finding
Continuous position finding is the calculation of the current vehicle position. It is already active when the ignition is switched on (circuit 15 ON) and is accomplished by the navigation processor integrated into the COMAND operating, display and controller unit (A40/3). During the switch-on phase (software is loaded), only the basic position finding (composite positioning) is available. After switching the ignition off, all important positioning parameters are stored for the duration of the run-on time of 30 min. After switching on the navigation system, 4 global positioning system (GPS) satellites are required for accurate position calculation. 3 satellites are sufficient for subsequent calculations.

If the user presses the "Current Position" button the current position of the vehicle is displayed on the navigation map.

The navigation processor continuously recalculates the position from the data of the ESP and BAS control unit (N47-5), the yaw rate and lateral acceleration sensor (B24/15) and the sequence of locations calculated via GPS. The evaluation of the vehicle movement is represented as a vector of distance and angle. Position finding takes place by comparing these vectors with the stored digital road data.

Input of the tire size (parameterization) is not required.

The navigation system continuously calculates the position of the vehicle using the following 3 methods:
^ Basic position finding (dead reckoning)
^ GPS position finding
^ Map-based position finding

The navigation processor synchronizes the 3 methods.

It is possible to enter the location manually on the COMAND operating, display and controller unit (A40/3). This may be useful after the vehicle has been transported (e.g. by ferry or train) or if there was no GPS reception at the start of the journey.