Requirements concerning the vehicle network ripple define the robustness of a DUT with respect to the vehicle network ripple originated by the generator. It is assumed that the interference originated by the generator, which interferes the supply voltage, is sinusoidal. Since the generator, which is coupled to the vehicle engine, works within a wide range of revolutions, the interference strength is defined for a frequency range and for a frequency response curve. The frequency response curve determines the form of the frequency changes, e.g., ramp, sawtooth etc., within the specified test duration. This requirement can be described by the following parameters.
Figure 36: Structure of vehicle network ripple
Example for content:
Figure 37: Frequency response curve
Representation example for vehicle network ripple
Denomination
|
Abbreviation
|
Min
|
Type
|
Max
|
Abs
|
Tolerance
|
Unit
|
|
|
|
|
|
|
|
|
|
|
Interference voltage
|
US
|
1,9
|
2
|
2,1
|
V
|
|
|
|
Internal resistance
|
RI
|
|
0.2
|
|
W
|
|
|
|
Test duration
|
t
|
9
|
10
|
11
|
min
|
|
|
|
Operating state : Switched on
Function state: A
Fault description: no fault
Additional specifications:
Apart from the a.m. specifications, it is always possible to give additional specifications for a test. These include, e.g., a test temperature which differs from general specifications, the test set-up etc.
|