Conti Temic Microelectronic Gmbh

Messerschmitt-Boelkow-Blohm Gmbh

Guenther Fendt

Hans Spies

Peter Hora

Alfons Woehrl

Helmut Riedel

Josef Baerenweiler

From a prescribed starting value, the emitting power of an obstacle detection beam increases or decreases according to a prescribed function at a prescribed rate. The received signal reflected from an obstacle is compared to a prescribed threshold. Once the received reflected power rises or falls to the threshold, the emitting power is not further increased or decreased respectively, but is maintained constant. Thereby, consumed and dissipated power is reduced, unnecessary excessive power use is avoided, and the detection range of the obstacle detection beam is adapted to the prevailing situation.

Method of operating an active obstacle warning system

A passive safety device (62) is triggered for protecting vehicle passengers in the event of a collision. The output signals of a signal acceleration sensor (1) are integrated to form a signal which triggers the deployment of the safety device when a threshold value for the integrated signal is exceeded and simultaneously additional criteria are met. These conditions are met in a simple circuit with a single acceleration sensor (1), so that the entire apparatus including the safety device (62) can be installed compactly in a steering wheel of a motor vehicle. In addition to a first signal evaluation channel in which the sensor signal is integrated once, there is at least one second signal evaluation channel including two integrators (20) and (23) in which the sensor signal is integrated twice to provide a distance signal that is evaluated by a further threshold value switch (24). The safety device (62) is only triggered if both the singly integrated signal and the doubly integrated signal exceed prescribed thresholds within a prescribed time period. Additionally, a rear collision impact recognition circuit and a hammer blow impact recognition circuit (31 to 36; 41, 28) is provided to block the triggering of the safety device. A rest circuit is also provided.

Apparatus for triggering a passive safety device for protecting

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Schrobenhausen, Germany

Guenther Fendt