Apparatus for triggering a passive safety device for protecting passengers in a vehicle
First Claim
1. A circuit arrangement for triggering a safety device for protecting passengers in a motor vehicle in response to a collision, comprising a single collision acceleration sensor (1), a first signal evaluating channel connected to an output of said sensor and including first means for evaluating an acceleration sensor output signal to produce a velocity signal, a second signal evaluation channel connected to said output of said sensor and including second means for evaluating said acceleration sensor output signal to produce a distance signal, and a logic circuit stage (61) for combing said velocity signal and said distance signal to selectively produce an output trigger signal for selectively triggering said safety device, said circuit arrangement further comprising a minor impact sensor circuit (41), and a rear impact sensor circuit (31 to 36), and wherein said first means of said first signal evaluation channel comprises a first integrator (7) connected in series with an arrangement of a plurality of threshold value switches, and wherein said logic circuit stage (61) comprises a first AND-gate (64) receiving as a first input, an output from a first threshold value switch (8) of said plurality having a low threshold value, said first AND-gate (64) receiving as a second input, a combined signal including an output of said minor impact sensor circuit and for a prescribed time duration an output of a timing circuit (12) for detecting a beginning of an impact, a first OR-gate (65) receiving as a first input, an output signal of said first AND-gate (64) and as a second input, an output signal of a second threshold value switch (9) of said plurality of threshold value switches in said first signal evaluation channel, a second AND-gate (66) receiving as a first input, an output signal of said first OR-gate (65) and as a second input, an output signal of said rear impact sensor circuit (31 to 36), a second OR-gate (67) receiving as a first input, an output signal of said second AND-gate (66) and as a second input, an output signal from a third threshold value switch (10) of said plurality of threshold value switches having a high threshold value, and a third AND-gate (68) receiving as a first input, an output signal from said second OR-gate (67) and as a second input, an output signal from said second signal evaluation channel, whereby an output signal of said third AND-gate (68) forms said output trigger signal for selectively triggering said safety device.
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Accused Products
Abstract
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.
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Citations
11 Claims
- 1. A circuit arrangement for triggering a safety device for protecting passengers in a motor vehicle in response to a collision, comprising a single collision acceleration sensor (1), a first signal evaluating channel connected to an output of said sensor and including first means for evaluating an acceleration sensor output signal to produce a velocity signal, a second signal evaluation channel connected to said output of said sensor and including second means for evaluating said acceleration sensor output signal to produce a distance signal, and a logic circuit stage (61) for combing said velocity signal and said distance signal to selectively produce an output trigger signal for selectively triggering said safety device, said circuit arrangement further comprising a minor impact sensor circuit (41), and a rear impact sensor circuit (31 to 36), and wherein said first means of said first signal evaluation channel comprises a first integrator (7) connected in series with an arrangement of a plurality of threshold value switches, and wherein said logic circuit stage (61) comprises a first AND-gate (64) receiving as a first input, an output from a first threshold value switch (8) of said plurality having a low threshold value, said first AND-gate (64) receiving as a second input, a combined signal including an output of said minor impact sensor circuit and for a prescribed time duration an output of a timing circuit (12) for detecting a beginning of an impact, a first OR-gate (65) receiving as a first input, an output signal of said first AND-gate (64) and as a second input, an output signal of a second threshold value switch (9) of said plurality of threshold value switches in said first signal evaluation channel, a second AND-gate (66) receiving as a first input, an output signal of said first OR-gate (65) and as a second input, an output signal of said rear impact sensor circuit (31 to 36), a second OR-gate (67) receiving as a first input, an output signal of said second AND-gate (66) and as a second input, an output signal from a third threshold value switch (10) of said plurality of threshold value switches having a high threshold value, and a third AND-gate (68) receiving as a first input, an output signal from said second OR-gate (67) and as a second input, an output signal from said second signal evaluation channel, whereby an output signal of said third AND-gate (68) forms said output trigger signal for selectively triggering said safety device.
Specification