Apparatus for determining emergency conditions of a vehicle

• US 5,594,647 A
• Filed: 05/02/1995
• Issued: 01/14/1997
• Est. Priority Date: 08/28/1992
• Status: Expired due to Fees

• Current Assignee: Kabushiki Kaisha Tokai RIKA Denki Seisakusho
• Original Assignee: Kabushiki Kaisha Tokai RIKA Denki Seisakusho
• Inventors: Okada, Hirofumi, Yasuda, Shigekazu
• Primary Examiner(s): Chin, Gary
• Application Number:
  US08/434,326
• Time in Patent Office: 623 Days
• Field of Search: 364/424.05, 280/734, 280/735, 180/274, 180/282, 307/10.1, 340/436, 340/438, 340/669
• US Class Current: 701/45
• CPC Class Codes: B60R 2021/0002 Type of accident
• CPC Class Codes: B60R 21/0132 responsive to vehicle motion parameters , e.g. to vehicle longitudinal or transversal deceleration or speed value
• CPC Class Codes: B60R 21/0133 by integrating the amplitude of the input signal

Abstract

An apparatus for determining emergency conditions of a vehicle including: an acceleration sensor which detects the acceleration of a vehicle and an operation-signal generating apparatus which establishes a signal level based on the signal outputted from the acceleration sensor in a circuit established in accordance with the kind of vehicle collision and which outputs a signal for actuating a passenger safety device when the established signal level exceeds a reference value which is predetermined according to the kind of vehicle collision. This allows the passenger safety device to be actuated at a suitable time according to vehicle collision.

Claims

1. An apparatus for determining emergency conditions of a vehicle, comprising:

an acceleration sensor which detects acceleration of a vehicle and outputs a signal that is converted into a waveform;

a plurality of integration means, each of which integrates the signal outputted from said acceleration sensor and uses a different cut-off frequency associated with a time constant corresponding to different kinds of vehicle collision, each said cut-off frequency being set in advance to distinguish between waveforms corresponding to each of said different kinds of vehicle collision;

a plurality of comparison means which respectively correspond to said plurality of integration means and each of which outputs a signal when a signal outputted from a corresponding said integration means exceeds a reference value which is predetermined according to the kind of vehicle collision; and

logical operation means which inputs the signals outputted from said plurality of comparison means and outputs a signal for actuating said passenger safety device for protecting a passenger.

2. An apparatus for determining emergency conditions of a vehicle according to claim 1, wherein said plurality of comparison means output signals when the kind of vehicle collision is a head-on collision with another vehicle or a kind where one of the side surfaces of a vehicle has been hit by another vehicle.

3. An apparatus for determining an emergency condition of a vehicle according to claim 1, wherein said plurality of comparison means also output signals to indicate that the vehicle is not in a collision.

4. An apparatus for determining emergency conditions of a vehicle according to claim 1, wherein said logical operation means comprises an OR circuit which outputs an expansion signal for expanding an air bag of an air bag system which serves as the passenger safety device.

5. An apparatus for determining emergency conditions of a vehicle according to claim 1, wherein said logical operation means is connected to an ignition circuit and outputs an expansion signal for expanding an air bag into an air bag system which serves as the passenger safety device through said ignition circuit.

6. An apparatus for determining emergency conditions of a vehicle based on a plurality of different types of vehicle collision, the apparatus comprising:

an acceleration sensor which detects acceleration of a vehicle and outputs a waveform signal in accordance with the type of vehicle collision; and

operation-signal generating means for generating an operation signal to actuate a passenger safety device for protecting an occupant of the vehicle, the operation-signal generating means

(1) establishing a plurality of signal levels based on the waveform signal output from said acceleration sensor, said signal levels corresponding to said types of vehicle collision, and, depending on the type of vehicle collision,

(2) outputting the operation signal to actuate the passenger safety device at a first time relative to said waveform when one of the established signal levels corresponding to one of the types of vehicle collision exceeds one reference value corresponding to said one type of vehicle collision, and (3) outputting the operation signal to actuate the passenger safety device at a second time relative to said waveform, which occurs at a time that is later than the first time, when another of the established signal levels corresponding to another of the types of vehicle collision exceeds another reference value corresponding to said another type of vehicle collision.

7. An apparatus for determining emergency conditions of a vehicle in accordance with claim 6, wherein said one signal level corresponds to a head-on collision and said another of said signal levels corresponds to an off-set collision.

8. An apparatus for determining emergency conditions of a vehicle according to claim 6, wherein said operation-signal generating means includes an integration circuit for integrating the signal outputted from said acceleration sensor and a comparison circuit for comparing a signal from said integration circuit with said one reference value.

9. An apparatus for determining emergency conditions of a vehicle according to claim 6, wherein said operation-signal generating means includes a plurality of circuits corresponding to said types of vehicle collision, the number of said circuits corresponding to the number of types of vehicle collision, and wherein said operation-signal generating means establishes a signal level for each circuit.

10. An apparatus for determining emergency conditions of a vehicle according to claim 6, wherein said operation signal is an expansion signal for expanding an air bag of an air bag system which serves as said passenger safety device.

11. An apparatus for determining emergency conditions of a vehicle according to claim 6, wherein said operation signal is a signal for locking a webbing of a retractor by a locking mechanism which winds and pays out a webbing which serves as said passenger safety device.

12. An apparatus for determining emergency conditions of a vehicle, comprising:

an acceleration sensor which detects acceleration of a vehicle and outputs a signal including a waveform;

a plurality of integrators, each integrator having associated therewith a different cut-off frequency associated with a time constant according to different kinds of vehicle collision, each said cut-off frequency being set in advance to distinguish between waveforms corresponding to each of said different kinds of vehicle collision by amplifying selected waveforms and suppressing unselected waveforms, the integrators integrating the signal outputted from said acceleration sensor and using said different cut-off frequencies associated with said time constants; and

comparison circuitry that outputs a signal to actuate said passenger safety device to protect a passenger when a signal outputted from one of said integrators exceeds a corresponding reference value that is predetermined according to the kind of vehicle collision, and that outputs a signal to actuate said passenger safety device to protect a passenger when a signal outputted from another one of said integrators exceeds a corresponding reference value that is predetermined according to a different kind of vehicle collision.

13. An apparatus for determining emergency conditions of a vehicle according to claim 12, wherein said plurality of integrators each comprises a low-pass filter, an amplification factor of which decreases at a frequency equal to or greater than a predetermined frequency.

14. An apparatus for determining emergency conditions of a vehicle according to claim 12, wherein said integrators integrate the signal from said acceleration sensor based on different time constants according to the kind of vehicle collision and generate signals exceeding the predetermined reference values only at the time of vehicle collision.

15. An apparatus for determining emergency conditions of a vehicle according to claim 12, wherein said comparison circuitry comprises a computer that compares the signals outputted from said integrators with the predetermined reference values.

16. An apparatus for determining emergency conditions of a vehicle according to claim 12, wherein said comparison circuitry comprises a plurality of comparison circuits and establishes a different predetermined reference value for each of said plurality of comparison circuits.

17. An apparatus for determining emergency conditions of a vehicle according to claim 12, wherein said comparison circuitry outputs an expansion signal which causes the expansion of an air bag of an air bag system which serves as the passenger safety device.

18. An apparatus for determining emergency conditions of a vehicle according to claim 12, wherein said comparison circuitry outputs a signal for locking a webbing of a retractor with a locking mechanism which winds and pays out a webbing which serves as the passenger safety device.

19. An apparatus for activating an occupant safety device of a vehicle upon collision of the vehicle, the apparatus comprising:

a single acceleration sensor connected with the vehicle to detect acceleration of the vehicle and to output an acceleration waveform signal; and

circuitry connected with the single acceleration sensor to (1) determine based on the acceleration waveform signal whether the vehicle collision is a head-on collision and to issue an activation signal to activate an occupant safety device at a first time relative to said waveform signal when the vehicle collision is said head-on collision, and (2) determine based on the acceleration signal whether the vehicle collision is an off-set collision and to issue an activation signal to activate said occupant safety device at a second time relative to said waveform signal, which occurs at a time that is later than the first time, when the vehicle collision is said off-set collision.

20. An apparatus according to claim 19, wherein said circuitry comprises:

a first integrator for integrating the acceleration signal and generating a first signal;

a first comparator for comparing the signal from the first integrator with a first predetermined reference value and generating a signal indicative of said head-on collision;

a second integrator for integrating the acceleration signal and generating a signal; and

a second comparator for comparing the signal from the second integrator with a second predetermined reference value and generating a signal indicative of said off-set collision.