S 430 (220.170) V8-4.3L (113.941) (2000)
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Basic location finding (dead reckoning)
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Map-supported location finding (map matching)
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GPS location finding
NOTE: Manual entry of vehicle location
It is possible to manually enter the location in the basic menu for designation entry by activating the menu field "Settings". This may be useful in the
following cases:
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After transport of the vehicle (e.g. train or ferry) or
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when GPS reception is not possible at the beginning of a trip.
Basic Location Finding
Basic location finding (dead reckoning) is the basic function of the continuous location finding feature. It is accomplished continuously by the navigation
processor (A40/3n2) when the ignition is switched on and is independent of the CD-ROM map. After switching off the ignition the current position is
stored for a delayed shut-off period.
The following information is calculated with the aid of the basic location finding feature:
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Distance traveled
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Direction of motion (forward or backward) and
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Direction in which vehicle is pointing.
NOTE: Basic location finding is accomplished approx. once each second.
Distance traveled
The navigation processor (A40/3n2) receives the signals from the speed sensors on the undriven wheels over discrete loads (not CAN) from the traction
system control module (N74).
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Left front axle VSS sensor (L6/1)
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Right front axle VSS sensor (L6/2)
NOTE: On the (J) version, only the signal from L6/2 is fed to the navigation processor (A40/3n2).
Evaluation of the wheel speed signals provides the distance traveled.
Direction of motion
The backup signal (from CAN passenger compartment bus) allows the navigation processor (A40/3n2) to recognize the direction of motion (forward or
backward).
Vehicle alignment
The navigation processor (A40/3n2) calculates the direction in which the vehicle is pointing (compass direction) from the difference in the signals from
the speed sensors (except (J)), the data from the gyrosensor and the sequence of locations calculated by GPS.
The difference between the calculated and actual distance traveled between two turning points is used automatically for recalibration of the tire
circumference (required due to tire wear).
Location finding errors with basic location finding