Device for deriving information about displacement of a vehicle component

• US 20080029329A1
• Filed: 07/17/2007
• Published: 02/07/2008
• Est. Priority Date: 08/02/2006
• Status: Active Grant

• Current Assignee: Takata Corporation (Ningbo Junsheng Investment Group Co., Ltd.)
• Original Assignee: Takata Corporation (Ningbo Junsheng Investment Group Co., Ltd.)
• Inventors: Aoki, Hiroshi, Ooi, Kazuya
• Granted Patent: US 7,717,217 B2
• Time in Patent Office: Days
• US Class Current: 180/274
• 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

Abstract

A collision detecting device which is installed in a vehicle comprises a metallic object to be detected having an extending surface which can be displaced toward a coil sensor according a vehicle collision and is arranged to face the sensor surface of the coil sensor.

Claims

1. A displacement information deriving device comprising:

a metallic object to be detected which is structured as a vehicle component;

a coil arranged to face the object to be detected;

a coil sensor which applies an AC magnetic field to the object to be detected when the coil is energized with alternative current and which detects impedance through the coil when energized; and

a deriving unit for deriving information about displacement of the object to be detected based on variations in impedance detected when the object to be detected is displaced toward the coil sensor in the event of a vehicle collision, wherein

the object to be detected is displaced toward the coil sensor according to the displacement of the vehicle component by the vehicle collision and the object to be detected has an extending surface arranged to face the sensor surface of the coil sensor.

2. A displacement information deriving device as claimed in claim 1, wherein the object to be detected is fixed to the vehicle component and is adapted to be displaced integrally with the vehicle component toward the coil sensor in the event of the vehicle collision.

3. A displacement information deriving device as claimed in claim 1, wherein the object to be detected is fixed to the coil sensor via an elastically deformable elastic body between the vehicle component and the coil sensor, and the object to be detected is pressed by the vehicle component according to the displacement of the vehicle component toward the coil sensor to move closer to the coil against the elastic force of the elastic body during the vehicle collision.

4. A displacement information deriving device as claimed in claim 3, wherein the elastic body is elastically deformed maintaining the parallel relation between the extending surface of the object to be detected and the sensor surface of the coil sensor when the object to be detected is moved closer to the coil sensor.

5. An occupant restraint system comprising:

a displacement information deriving device comprising;

a metallic object to be detected which is structured as a vehicle component;

a coil arranged to face the object to be detected;

a coil sensor which applies an AC magnetic field to the object to be detected when the coil is energized with alternative current and which detects impedance through the coil when energized; and

a deriving unit for deriving information about displacement of the object to be detected based on variations in impedance detected when the object to be detected is displaced toward the coil sensor in the event of a vehicle collision, wherein

the object to be detected is displaced toward the coil sensor according to the displacement of the vehicle component by the vehicle collision and the object to be detected has an extending surface arranged to face the sensor surface of the coil sensor;

an occupant restraint device for restraining a vehicle occupant during a vehicle collision; and

a control device for controlling the occupant restraint device according to the information derived by the deriving unit.

6. An occupant restraint system as claimed in claim 5, wherein

the coil of the displacement information deriving device is arranged to face a door outer panel of a vehicle door as the vehicle component, and wherein

the occupant restraint device is controlled by the control device to restrain the vehicle occupant in the event of a lateral vehicle collision.

7. A vehicle comprising:

an engine/running system;

an electrical system;

an actuation control device for conducting the actuation control of the engine/running system and the electrical system;

a metallic object to be detected which can be displaced by a vehicle collision;

a sensor device for deriving information about displacement of the object to be detected; and

a control signal output device for outputting control signal to an object to be controlled based on the information derived by the sensor device, wherein

the sensor device comprises a displacement information deriving device comprising;

a metallic object to be detected which is structured as a vehicle component;

a coil arranged to face the object to be detected;

a coil sensor which applies an AC magnetic field to the object to be detected when the coil is energized with alternative current and which detects impedance through the coil when energized; and

a deriving unit for deriving information about displacement of the object to be detected based on variations in impedance detected when the object to be detected is displaced toward the coil sensor in the event of a vehicle collision, wherein the object to be detected is displaced toward the coil sensor according to the displacement of the vehicle component by the vehicle collision and the object to be detected has an extending surface arranged to face the sensor surface of the coil sensor.

8. A displacement information deriving method comprising:

using a coil sensor which is arranged to face a metallic object to be detected, wherein the object to be detected is structured as a vehicle component, and the object to be detected can be displaced toward the coil sensor according to a vehicle collision, and the object to be detected has an extending surface arranged to face the sensor surface of the coil sensor, and

energizing the coil of the coil sensor with alternative current to apply an AC magnetic field to the object to be detected, detecting impedance through the coil when energized, and detecting variation in impedance through the coil when the object to be detected is displaced toward the coil sensor during a vehicle collision, whereby

detection characteristics about variation in impedance relative to the distance between the object to be detected and the coil sensor are obtained and information about the displacement of the object to be detected is derived based on the detection characteristics.