Basic location finding, function - GF82.61-P-3006TJ

MODEL 211.0 /2 with CODE (529) HIGH Class Japan

Position finding

Fig 1: View Of Basic Position Finding

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

With code (529) HIGH Class Japan the navigation processor is integrated in the COMAND operating, display and control unit (A40/3).

Basic location finding is the base function of continuous map finding. It is carried out continuously by the navigation processor in the event of "terminal 15R ON", and is independent of the DVD-ROM map. The current position is stored after "terminal 15R OFF."

The following information is calculated with the aid of basic location finding:

Direction of travel (forward or reverse)
Distance traveled
Direction in which vehicle is pointing

The basic location finding is carried out approx. 1/s.

Direction of motion

Using the "wheel rotational direction" signal, which is also sent by the ESP, SPS [PML] and BAS control unit (N47-5) and transmitted by the central gateway control unit (N93) to the CAN interior (CAN-B), the navigation processor detects the direction of travel (forward or reverse).

Mileage covered

The navigation processor receives the signals for the wheel RPM from the ESP, SPS [PML] and BAS control unit (N47-5) via engine compartment CAN (CAN-C). The evaluation of the wheel speed signals reveals the mileage covered.

Vehicle orientation

From the yaw rate sensor (gyro sensor) data and the sequence of locations calculated with GPS the navigation processor calculates the alignment (compass direction) of the vehicle.

The difference between the calculated mileage and actual mileage covered between 2 turning-off points is used to re-calibrate the tire circumference automatically.

Errors with basic location finding

Rolling with "terminal 15R OFF" or transport of the vehicle also distort the position finding.

In both cases, this deviation is automatically corrected by the navigation processor on receipt of the GPS data.

Calibration

Wheel calibration is necessary following a tire change. For this purpose, it is necessary to enter the tire size, e.g. 225/060/016 and the coding, whether new (depth of tread approx. 5 up to 10 mm) or used tires (depth of tread approx. 3 up to 5 mm) were mounted.

The entry is accomplished with Star Diagnosis or directly at the COMAND operating, display and control unit (A40/3). A special calibration drive is not required.

Global positioning system location finding, function

GF82.61-P-3007TJ