EP0590476A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Crash/non-crash discrimination using frequency components of acceleration uniquely generated upon crash impact
Assignee: NEC Corp
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Filing: 1993-09-21
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Granted: —
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Expires: 2013-09-21
Abstract
Abstract In a crash detection apparatus, the output signal of an accelerometer is integrated at intervals and a velocity signal is produced. Those frequency components of the accelerometer output which appear uniquely during a vehicle crash are extracted and their amplitude is squared to produce an impact energy signal. An airbag is operated when the velocity signal exceeds a first threshold, or when a sum of the velocity and impact energy signals exceeds a second threshold, or operated when the impact energy signal exceeds a third threshold. In a modified embodiment, the accelerometer output is integrated both at longer and shorter intervals to produce a long-term and a short-term velocity signal. The airbag is operated when the long-term velocity signal exceeds a first threshold, or when the short-term velocity signal and the impact energy signal simultaneously exceed a second and a third threshold, respectively. <IMAGE>
Inventors
- 👤 Masahiro c/o NEC Home Electronics Ltd. Miyamori
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-27 07:15
CPC Classifications
B; B60; B60R; B60R21/00; B60R21/01; B60R21/013; B60R21/0132; B60R21/01332; B60R21/01336; B60R21/0133
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
115 words
A crash detection apparatus adapted to be mounted on a vehicle for operating an inflatable occupant restraint system, comprising: an accelerometer for producing an accelerometer signal representative of acceleration/deceleration of the vehicle during a vehicle crash; integrator means for integrating said accelerometer signal at intervals and producing a velocity signal; bandpass filter means for filtering a frequency range of said accelerometer signal which appears uniquely during said vehicle crash; squaring means for squaring amplitude of the bandpass filtered accelerometer signal and producing an impact energy signal; and decision means for producing a deployment signal in accordance with said velocity signal and said impact energy signal and applying said deployment signal to said occupant restraint system.
Claim 2
Dependent Claim
129 words
A crash detection apparatus as claimed in clam 1, wherein said decision means comprises: first comparator means for comparing said velocity signal with a first threshold value and producing a first deployment signal when said velocity signal exceeds said first threshold value; adder means for summing said velocity signal and said impact energy signal; second comparator means for comparing the output of the adder means with a second threshold value and applying a second deployment signal to said restraint system when said output signal of the adder means exceeds said said second threshold value; and third comparator means for comparing said impact energy signal with a third threshold value and applying a third deployment signal to said restraint system when said impact energy signal exceeds said third threshold value.
Claim 3
Dependent Claim
31 words
A crash detection apparatus as claimed in claim 1 or 2, further comprising limiter means for preventing the output signal of said integrator means from reducing below a predetermined negative level.
Claim 4
Dependent Claim
138 words
A crash detection apparatus adapted to be mounted on a vehicle for operating an inflatable occupant restraint system, comprising: an accelerometer for producing an accelerometer signal representative of acceleration/deceleration of the vehicle during a vehicle crash; long-term integrator means for integrating said accelerometer signal at longer intervals and producing a long-term velocity signal; short-term integrator means for integrating said accelerometer signal at shorter intervals and producing a short-term velocity signal; bandpass filter means for filtering a frequency range of said accelerometer signal which appears uniquely during said vehicle crash; squaring means for squaring amplitude of the bandpass filtered accelerometer signal and producing an impact energy signal; and decision means for producing a deployment signal in accordance with said long-term and short-term velocity signals and said impact energy signal and applying said deployment signal to said occupant restraint system.
Claim 5
Dependent Claim
136 words
A crash detection apparatus as claimed in claim 4, wherein said decision means comprises: first comparator means for comparing said long-term velocity signal with a first threshold value and applying a first deployment signal to said restraint system when said velocity signal exceeds said first threshold value; second comparator means for comparing said short-term velocity signal with a second threshold value and producing an output signal when said short-term velocity signal exceeds said said second threshold value; third comparator means for comparing said impact energy signal with a third threshold value and producing an output signal when said impact energy signal exceeds said third threshold value; and coincidence detection means for applying a second deployment signal to said restraint system when there is a coincidence between the output signals of said second and third comparator means.
Claim 6
Dependent Claim
56 words
A crash detection apparatus as claimed in claim 4 or 5, further comprising first limiter means for preventing the output signal of said long-term integrator means from reducing below a first predetermined negative level and second limiter means for preventing the output signal of said short-term integrator means from reducing below a second predetermined negative level.
Claim 7
Dependent Claim
65 words
A crash detection apparatus as claimed in claim 5 or 6, wherein said coincidence detection means includes; means for stretching the duration of the output signal of said third comparator means; and a coincidence gate for producing said second deployment signal when there is a coincidence between the stretched output signal of the third comparator means and the output signal of said second comparator means.
Claim 8
Dependent Claim
103 words
In an apparatus adapted to be mounted on a vehicle for operating an inflatable occupant restraint system, the apparatus comprising an accelerometer for producing an accelerometer signal representative of acceleration/deceleration of the vehicle during a vehicle crash, a method comprising the steps of; a) integrating said accelerometer signal at intervals and producing a velocity signal; b) extracting frequency components of said accelerometer signal which appear uniquely during said vehicle crash; c) squaring amplitude of the extracted frequency components and producing therefrom an impact energy signal; and d) operating said occupant restraint system in response to said velocity signal and said impact energy signal.
Claim 9
Dependent Claim
99 words
A method as claimed in claim 8, wherein the step (d) comprises: d1) comparing said velocity signal with a first threshold value and operating said restraint system when said velocity signal exceeds said first threshold value; d2) producing a sum of said velocity signal and said impact energy signal; d3) comparing the sum with a second threshold value and operating said restraint system when said sum exceeds said said second threshold value; and d4) comparing said impact energy signal with a third threshold value and operating said restraint system when said impact energy signal exceeds said third threshold value.
Claim 10
Dependent Claim
124 words
In an apparatus apparatus adapted to be mounted on a vehicle for operating an inflatable occupant restraint system, the apparatus comprising an accelerometer for producing an accelerometer signal representative of acceleration/deceleration of the vehicle during a vehicle crash, a method comprising the steps of: a) integrating said accelerometer signal at longer intervals and producing therefrom a long-term velocity signal; b) integrating said accelerometer signal at shorter intervals and producing therefrom a short-term velocity signal; c) extracting frequency components of said accelerometer signal which appear uniquely during said vehicle crash; d) squaring amplitude of the extracted frequency components and producing an impact energy signal; and e) operating said occupant restraint system in response to said long-term and short-term velocity signals and said impact energy signal.
Claim 11
Dependent Claim
91 words
A method as claimed in claim 10, wherein the step (e) comprises: e1) comparing said long-term velocity signal with a first threshold value and operating said restraint system when said velocity signal exceeds said first threshold value; e2) comparing said short-term velocity signal with a second threshold value and comparing said impact energy signal with a third threshold value; and e3) operating said restraint system when the short-term velocity signal and said impact energy signal are simultaneously determined by the step (e2) as exceeding said second and third threshold values, respectively.
References Cited (Backward Citations)
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