Passive safety system and determination device

• US 7,406,376 B2
• Filed: 12/21/2004
• Issued: 07/29/2008
• Est. Priority Date: 01/28/2004
• Status: Expired due to Fees

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Higuchi, Hiroshi, Ide, Seiya
• Primary Examiner(s): Keith, Jack W
• Assistant Examiner(s): Diacou, Ari M
• Application Number:
  US11/016,893
• Publication Number:
  US 20050161920A1
• Time in Patent Office: 1,316 Days
• Field of Search: None
• US Class Current: 701/47
• 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 21/01332 by frequency or waveform analysis
• CPC Class Codes: B60R 21/0136 responsive to actual contact with an obstacle , e.g. to vehicle deformation, bumper displacement or bumper velocity relative to the vehicle monitoring crash strength in combination with passenger seat detection B60R21/01558
• CPC Class Codes: B60R 21/0156 by deceleration

Abstract

A determination device includes a single acceleration sensor for measuring an acceleration of a vehicle and a determination circuit for determining severity of a collision in an accident. A plastic deformation pulse detection section and an elastic deformation pulse detection section of the determination circuit detect a plastic deformation pulse and an elastic deformation pulse, respectively, from a waveform of measured accelerations. A severity determination section of the detection circuit determines the severity of a collision based on a correlation between a vehicle speed and a plastic deformation pulse, and a correlation between the vehicle speed, the plastic deformation pulse, and an elastic deformation pulse.

Claims

1. A determination device for a passive safety device that operates according to severity of a collision in a vehicle accident comprising:

a single acceleration sensor configured to measure an acceleration of a vehicle to provide an acceleration wave form; and

a determination circuit that includes a plastic deformation pulse detection section, an elastic deformation pulse detection section, and a severity determination section, wherein

the determination circuit is electrically connected with the acceleration sensor;

the plastic deformation pulse detection section is configured to detect a plastic deformation pulse by separating a plastic deformation pulse component having a first frequency range that is caused by damage of individual parts of the vehicle from the acceleration waveform;

the elastic deformation pulse detection section is configured to detect an elastic deformation pulse by separating an elastic deformation pulse component having a second frequency range that is caused by damage of the entire vehicle to be lower than the first frequency range from the acceleration waveform;

the severity determination section is configured to determine the severity of a collision based on a correlation between a vehicle speed, the plastic deformation pulse, and the elastic deformation pulse;

the plastic deformation pulse detection section is configured to calculate a first average acceleration of the plastic deformation pulse in a predetermined time interval;

the elastic deformation pulse detection section is configured to calculate a second average acceleration of the elastic deformation pulse in a predetermined time interval;

the severity determination section is configured to calculate a weighting factor by dividing an absolute value of the first average acceleration minus the second average acceleration by the second average acceleration; and

the severity determination section determines the severity of a collision using the weighting factor.

2. The determination device according to claim 1, wherein:

the severity determination section calculates a severity operator by multiplying the weighting factor by the absolute value when the second average acceleration is higher than a predetermined threshold; and

the severity determination section determines the severity of a collision by comparing the severity operator with a threshold value.

3. The determination device according to claim 1, wherein:

the plastic deformation pulse detection section further includes a high pass filter having a cutoff frequency of 60 Hz to 70 Hz configured for separating the plastic deformation pulse component with the high pass filter.

4. The determination device according to claim 1, wherein:

the elastic deformation pulse detection section further includes a low pass filter having a cutoff frequency of 5 Hz to 10 Hz configured for separating the elastic deformation pulse component.

5. The determination device according to claim 1, wherein the acceleration sensor and the determination circuit are arranged in a module.

6. The determination device according to claim 5, wherein the module is arranged in about a middle of a side-to-side line of the vehicle.