Activation device for passenger protection apparatus

• US 20040002802A1
• Filed: 05/23/2003
• Published: 01/01/2004
• Est. Priority Date: 06/27/2002
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Ide, Seiya, Ogata, Yoshihisa
• Granted Patent: US 6,978,200 B2
• Time in Patent Office: Days
• US Class Current: 701/45
• CPC Class Codes: B60R 2021/0006 Lateral collision
• CPC Class Codes: B60R 2021/01327 Angular velocity or angular acceleration
• CPC Class Codes: B60R 21/013 including means for detecting collisions, impending collisions or roll-over
• CPC Class Codes: B60R 21/0132 responsive to vehicle motion parameters , e.g. to vehicle longitudinal or transversal deceleration or speed value

Abstract

An activation device for a passenger protection apparatus is made up of a sensor for detecting a roll angular velocity of a vehicle, a unit for calculating a roll relative angle on the basis of the roll angular velocity, and a unit for making a judgment indicating a roll of the vehicle when the velocity and the angle satisfy a threshold condition. A control unit activates an air bag when making a judgment indicating a roll. A vehicle collision state is discriminated on the basis of right-hand and left-hand accelerations detected by acceleration sensors and the threshold condition for the judgment on a roll of the vehicle is switched in accordance with the collision state. This enables a trip-over type roll to be detected at an early stage for activating the passenger protection apparatus quickly.

Claims

1. An activation device for a passenger protection apparatus which is made to activate said passenger protection apparatus in accordance with a behavior of a vehicle, comprising:

an angular velocity sensor for detecting a roll angular velocity of said vehicle;

relative angle calculating means for calculating a roll relative angle of said vehicle on the basis of the roll angular velocity detected by said angular velocity sensor;

roll judging means for making a judgment indicating the occurrence of a roll of said vehicle when the roll angular velocity detected by said angular velocity sensor and the vehicle roll relative angle calculated by said relative angle calculating means satisfy a predetermined threshold condition;

drive control means for activating said passenger protection apparatus when said roll judging means makes the vehicle roll judgment;

a plurality of acceleration sensors for detecting accelerations of said vehicle in lateral directions;

collision state discriminating means for making a discrimination of a collision state of said vehicle on the basis of the accelerations detected by said plurality of acceleration sensors; and

threshold switching means for setting said predetermined threshold condition for the vehicle roll judgment in accordance with the collision state discriminated by said collision state discriminating means.

2. The device according to claim 1, wherein said roll judging means sets a threshold line on a two-dimensional map using a roll angular velocity and a roll relative angle as parameters and makes a judgment indicating the occurrence of a roll of said vehicle when a history line drawn on the basis of the roll angular velocity detected by said angular velocity sensor and the roll relative angle calculated by said relative angle calculating means runs from a non-roll area lying on a side of an origin with respect to said threshold line to a roll area lying on a side opposite to said origin with respect to said threshold line, and said threshold switching means sets said threshold line in accordance with the collision state discriminated by said collision state discriminating means.

3. The device according to claim 2, wherein said plurality of acceleration sensors includes:

a first acceleration sensor located at a predetermined position of said vehicle for detecting and outputting a first acceleration; and

a second acceleration sensor located at another predetermined position different from the first-mentioned predetermined position in right-hand and left-hand directions of said vehicle for detecting and outputting a second acceleration, and

said threshold switching means includes;

collision judging means for making a judgment indicating the occurrence of a collision against a side surface of said vehicle when said first acceleration exceeds a predetermined value or when said second acceleration exceeds another predetermined value; and

a phase difference discriminating means for, when said collision judging means makes a judgment that a collision against the side surface of said vehicle occurs, making a discrimination as to whether or not a phase difference between said first and second accelerations is below a predetermined phase difference, and

said threshold switching means sets a normal judgment threshold line as said threshold line when said collision judging means makes a judgment indicating no collision against the side surface of said vehicle, and sets a trip-over type judgment threshold line as said threshold line when said collision judging means makes a judgment indicating the occurrence of a collision against the side surface of said vehicle and said phase difference discriminating means makes a discrimination of a phase difference between said first and second accelerations being below said predetermined phase difference, and sets a side collision judgment threshold line as said threshold line when said collision judging means makes a judgment indicating the occurrence of a collision against the side surface of said vehicle and said phase difference discriminating means makes a discrimination of a phase difference between said first and second accelerations being equal to or more than said predetermined phase difference.

4. The device according to claim 3, wherein said trip-over type judgment threshold line is set closer to said origin than said normal judgment threshold line and said side collision judgment threshold line on said two-dimensional map.

6. The device according to claim 1, wherein said passenger protection apparatus includes at least one of a curtain air bag designed to spread into a curtain-like configuration along a side surface portion of said vehicle, a seat belt with a pretensioner and an apparatus made to take up a seat belt in a repeated fashion through the use of drive means.

5. An activation device for a passenger protection apparatus which is made to activate said passenger protection apparatus in accordance with a behavior of a vehicle, comprising:

roll detecting means for detecting a rotation of said vehicle in its right-hand and left-hand directions;

roll judging means for making a judgment on a roll of said vehicle on the basis of a result of the detection by said roll detecting means;

drive control means for activating said passenger protection apparatus when said roll judging means makes a judgment indicating the occurrence of a roll of said vehicle; and

trip-over type discriminating means for making a discrimination of a possibility of the occurrence of a trip-over type roll,

said roll judging means making a judgment indicating the occurrence of a roll of said vehicle at an earlier timing than normal when said trip-over type discriminating means discriminates a high possibility of the occurrence of the trip-over type roll.

7. The device according to claim 5, wherein said passenger protection apparatus includes at least one of a curtain air bag designed to spread into a curtain-like configuration along a side surface portion of said vehicle, a seat belt with a pretensioner and an apparatus made to take up a seat belt in a repeated fashion through the use of drive means.

8. An activation device for a passenger protection apparatus which is made to activate said passenger protection apparatus in accordance with a behavior of a vehicle, comprising:

roll judging means for detecting the behavior of said vehicle to make a judgment indicating the occurrence of a roll of said vehicle when the vehicle behavior detected satisfies a predetermined condition;

drive control means for activating said passenger protection apparatus when said roll judging means makes a judgment indicating the occurrence of a roll of said vehicle;

a plurality of acceleration sensors for detecting accelerations of said vehicle in its right-hand and left-hand directions;

collision state discriminating means for making a discrimination of a collision state of said vehicle on the basis of each of the accelerations detected by said plurality of acceleration sensors; and

threshold switching means for setting said predetermined condition for the judgment on a roll of said vehicle in accordance with the collision state discriminated by said collision state discriminating means.

9. An activation device for a passenger protection apparatus which is made to activate said passenger protection apparatus in accordance with a behavior of a vehicle, comprising:

roll judging means for detecting the behavior of said vehicle to make a judgment indicating the occurrence of a roll of said vehicle when the vehicle behavior detected satisfies a predetermined condition;

drive control means for activating said passenger protection apparatus when said roll judging means makes a judgment indicating the occurrence of a roll of said vehicle; and

trip-over type discriminating means for making a discrimination of a possibility of the occurrence of a trip-over type roll,

said roll judging means making a judgment indicating the occurrence of a roll of the vehicle at an earlier timing than normal when said trip-over type discriminating means makes a discrimination of a high possibility of the occurrence of a trip-over type roll.