Patent ID: 7774116

Claim:
A device for controlling a passenger protection system of a motor vehicle, comprising: at least one structure-borne noise sensor disposed to pick up vehicle body vibrations and to output a structure-borne noise signal; an evaluation device connected to receive the structure-borne noise signal from said sensor and to evaluate the structure-borne noise signal for generating information about an impact object and/or a characteristic of a collision; said evaluation device being configured to analyze the sensor signal in respect of the frequencies contained therein, by: dividing a frequency spectrum contained in a signal section into a number of frequency bands; determining a signal energy for each frequency band; and standardizing the signal energy of the frequency bands, thereby relating the signal energy of each of the frequency bands to a signal energy of a specific reference frequency band, and comparing resulting ratio curves with predetermined threshold values; wherein the passenger protection system is activated in dependence on the information about the impact object and/or the characteristic of the collision.