System and method for the magnetic detection of the presence of objects in a blind angle of an automobile vehicle

• US 20070139175A1
• Filed: 08/18/2003
• Published: 06/21/2007
• Est. Priority Date: 08/18/2003
• Status: Active Grant

• Current Assignee: FICO Mirrors SA (Panasonic Holdings Corporation)
• Original Assignee: FICO Mirrors SA (Panasonic Holdings Corporation)
• Inventors: Daura Luna, Francesc, Servera Serapio, Llorenc
• Granted Patent: US 7,489,234 B2
• Time in Patent Office: Days
• US Class Current: 340/435
• CPC Class Codes: G01V 3/081 the magnetic field is produced by the objects or geological structures characterised by the method of magnetic field measurement G01R33/00
• CPC Class Codes: G01V 3/087 the earth magnetic field being modified by the objects or geological structures
• CPC Class Codes: G01V 3/15 specially adapted for use during transport, e.g. by a person, vehicle or boat
• CPC Class Codes: G08G 1/166 for active traffic, e.g. moving vehicles, pedestrians, bikes
• CPC Class Codes: G08G 1/167 Driving aids for lane monitoring, lane changing, e.g. blind spot detection

Abstract

A system and method for the magnetic detection of the presence of objects in a blind angle of an automobile vehicle is disclosed. The system comprises a first means of detection of distortion of the earth'"'"'s magnetic field caused by the entry of a ferromagnetic object into a blind angle, a second, a third and some a means of detection of magnetic distortion deriving from the vehicle'"'"'s trajectory, inclination and/or vibration and magnetic fields generated inside the actual vehicle, respectively, all associated with an electronic circuit. The method comprises employing the proposed system to, through the generation of a table relating trajectory, inclination and/or vibrations or magnetic fields generated inside the vehicle with a corresponding distortion of the magnetic field due to the specific circumstances, neutralise the effects of said possible magnetic distortion on the detection of said object.

Claims

1. A system for the detection of the presence of objects in a blind angle of an automobile vehicle, installed in an automobile vehicle and comprising:

first means of detection of distortion of the earth'"'"'s magnetic field caused by the entry of an object, containing at least one ferromagnetic material piece, in a zone of said blind angle covered by said first means of detection that supplies electric signals, on the basis of the value of said magnetic field, to an electronic circuit with a digitising stage for said signals,

a second stage that analyses the signals obtained after said digitising;

a first stage that generates variable output signals on the basis of the results of said analysis; and

second means of detection for any possible magnetic distortion generated from the trajectory of said automobile vehicle, associated with said electronic circuit and intended to neutralise the influence of said possible magnetic distortion on the detection of said first means.

2. A detection system in accordance with claim 1, further comprising third means of detection of any possible magnetic distortion deriving from the vehicle'"'"'s inclination and/or vibration, associated with the electronic circuit.

3. A detection system in accordance with claim 1, further comprising fourth means of detection of any possible magnetic distortion deriving from magnetic fields generated within the vehicle, associated with the cited electronic circuit.

4. A detection system in accordance with claim 1, wherein said second means of detection comprises at least one accelerometer.

5. A detection system in accordance with claim 1, wherein said second means of detection comprises at least means of data acquisition employing a turning sensing pulse system located at least on one of the vehicle'"'"'s wheels.

6. A detection system in accordance with claim 1, wherein said second means of detection comprise at least one turning detection device located on the vehicle'"'"'s steering wheel.

7. A detection system in accordance with claim 2, wherein said second means of detection and said third means of detection comprises at least one 2-axis accelerometer.

8. A detection system in accordance with claim 3, wherein said fourth means of detection comprises at least two magnetic field sensors located inside the vehicle, connected in common mode, distanced from each other and positioned in such a manner that they generate very similar output signals when one of said magnetic fields is produced inside the vehicle.

9. A detection system in accordance with claim 1, wherein said first means of detection comprises at least one magnetic sensor housed inside a rear-view mirror assembly outside the vehicle.

10. A detection system in accordance with claim 8, wherein said sensors are magnetoresistive.

11. A detection system in accordance with claim 8, wherein said sensors are selected from the group consisting of flux-gate magnetometers, hall type sensors and magneto-inductive sensors.

17. A detection system in accordance with claim 9, wherein said sensors are magnetoresistive.

18. A detection system in accordance with claim 9, wherein said sensors are selected from the group consisting of flux-gate magnetometers, hall type sensors and magneto-inductive sensors.

12. A method of detection of the presence of objects in a blind angle of an automobile vehicle of the type that, is based on the use of first means of detection of distortion in the earth'"'"'s magnetic field caused by the entry of an object, which contains at least one ferromagnetic material, in a zone of said blind angle covered by said first means of detection and an electronic system, comprising:

carrying out the detection of the entry of said object into said zone,

obtaining signals that represent said detection,

processing and analysing of said signals,

generating of some variable output signals on the basis of the results of said analysis,

carrying out, by means of said electronic system and at least some second means of detections, the detection of possible magnetic distortion deriving from the trajectory of said automobile vehicle, and

processing and analysing of signals that are representative of said possible magnetic distortion deriving from the automobile vehicle'"'"'s trajectory, in order to neutralise its effect on the detection obtained by the first means of detections.

13. A method of detection in accordance with claim 12, further comprising carrying out, using said electronic system and at least third means of detection of possible magnetic distortion deriving from the inclination and/or vibration of the automobile vehicle, the processing and analysis of signals representative of said possible magnetic distortion deriving from the inclination and/or vibration of the automobile vehicle in order to neutralise their effect on the detection obtained by the first means of detections.

14. A method of detection in accordance with claim 13, further comprising carrying out, by means of said electronic system and a fourth means of detection of possible magnetic distortions produced by magnetic fields generated inside the vehicle itself, the processing and analysis of signals representative of said possible magnetic distortions produced by magnetic fields generated inside the vehicle itself in order to neutralise its effect on the detection obtained by the first means of detections.

15. A method of detection in accordance with claim 14, wherein for each of the possible trajectories adopted by the vehicle and/or of the possible positions of inclination and/or vibration suffered by the same and/or of the magnetic fields generated inside the vehicle itself, after said processing and analysis of the signals representative of the possible magnetic distortions, it comprises the storing, by means of the electronic system, of distortion values of the earth'"'"'s magnetic field, with these values forming a table that relates trajectory, inclination and/or vibration or magnetic fields generated inside the vehicle with the corresponding distortion of the magnetic field due to the specific circumstances.

16. A method of detection in accordance with claim 15, wherein at least one of said values, representative of the vehicle'"'"'s circumstances at any moment, with said circumstances being known through the second, third and fourth means of detection, is operated with the distortion value of the earth'"'"'s magnetic field obtained by the first means of detection for this same instant.