Impact sensor for motor vehicles or the like
First Claim
1. An impact sensor, especially for sensing a collision of a motor vehicle or the like travelling in a forward driving direction (R), comprising a plurality of acceleration detectors each having a sensitivity axis oriented in a different direction and each generating an output signal in response to an impact, a separate signal evaluating circuit means connected to each detector for individually evaluating each of said output signals to determine whether it exceeds a preliminary threshold value (a, a'"'"') and then to generate an evaluated output signal (V, V'"'"'), means for providing a first threshold value and means for providing a second threshold value, whereby said first threshold value is larger than said second threshold value, and signal validating means connected to said signal evaluating means for generating a control signal for activating passive safety devices if an evaluated output signal generated by at least one of said signal evaluating circuit means is larger than said first threshold value and simultaneously a further evaluated output signal generated by another signal evaluating circuit means is larger than said second threshold value.
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Accused Products
Abstract
An impact sensor for detecting a collision of a motor vehicle or the like has at least two acceleration detectors, and a signal evaluating circuit for each detector for evaluating the output signals of the respective acceleration detectors. The evaluated signals are passed through a logic signal interpreting circuit to provide a control signal for triggering passive safety devices such as an inflatable air bag. In order to trigger the passive safety devices as quickly as possible in response to an impact or collision, and in order to determine the angular direction of the impact, several acceleration detectors having oriented sensitivity axes are provided, whereby the sensitivity axes of separate detectors are oriented in different directions. The signal evaluation and interpretation to provide the triggering signal make sure that only determined output signals of the acceleration detectors cause the intended triggering preferably only for frontal impact collisions.
103 Citations
10 Claims
- 1. An impact sensor, especially for sensing a collision of a motor vehicle or the like travelling in a forward driving direction (R), comprising a plurality of acceleration detectors each having a sensitivity axis oriented in a different direction and each generating an output signal in response to an impact, a separate signal evaluating circuit means connected to each detector for individually evaluating each of said output signals to determine whether it exceeds a preliminary threshold value (a, a'"'"') and then to generate an evaluated output signal (V, V'"'"'), means for providing a first threshold value and means for providing a second threshold value, whereby said first threshold value is larger than said second threshold value, and signal validating means connected to said signal evaluating means for generating a control signal for activating passive safety devices if an evaluated output signal generated by at least one of said signal evaluating circuit means is larger than said first threshold value and simultaneously a further evaluated output signal generated by another signal evaluating circuit means is larger than said second threshold value.
Specification