User's Manual

TSS 2. Generation, “AUDI B6 / C6”
Tire Safety System TSS 2nd. Generation,”AUDI B6 / C6”
Dept. BEE
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c
Bedienungsanleitung TSS 2.
Generation, “AUDI B6 / C6
User Manual 2
nd
Generation “TSS AUDI B6 / C
6
freigegeben am /date of release
11.05.04
3 Warning algorithm
The reference pressures to be monitored can be notified to the system by 2 different
methods.
a) Reference pressure specified via tabulated value
b) Reference pressure specified by calibration
If reference pressures are specified via tabulated values, the reference pressures to be
monitored are placed in a table.
If reference pressures are specified via calibration, the driver instructs the system through a
calibration command to accept the actual measured pressure as the reference pressure
value (calibration can be started by pressing a key or selecting a menu item).
The value is accepted for a specific position once the positions of the wheels are detected
and confirmed. The defined reference pressure is verified by the system for plausibility of the
pressure values prior to acceptance (comparison by axle of reference pressures with
HighLine, minimum pressure).
The tire pressure changes only slowly during normal operation. A gradual pressure drop
through diffusion is typical. A sudden pressure loss occurs only in isolated cases.
Spontaneous blow-outs without previous history are extremely rare; in this case the driver will
notice the reaction of the vehicle before even the fastest monitoring system can trigger a
warning.
The calculation of the warning limits uses the isochoric relationship between pressure and
temperature and thus enables the same warning precision to be achieved over a wide
temperature range.
In the case of slow temperature changes, the temperature of the wheel electronics is
equivalent to the average air temperature of the tire. The temperature of the wheel
electronics can therefore be used to calculate the isochoric linears. In the case of sudden
temperature changes (e.g. due to heavy braking), the temperature of the wheel electronics is
higher than the average air temperature of the tires due to the improved thermal coupling at
the rim. This correlation is considered in the control unit and corrected.
The tire temperature is considered in the comparison between current tire pressure and
reference pressure (isochoric evaluation, see Annex 1). During calibration, the system uses
reference pressure and temperature to calculate valid reference values for the current tire
temperature. There are two distinct warnings to indicate low pressure: