Vehicle lane departure system based on magnetic field flux detection

• US 9,278,691 B1
• Filed: 09/18/2014
• Issued: 03/08/2016
• Est. Priority Date: 09/18/2014
• Status: Active Grant

• Current Assignee: Flextronics America LLC (Flextronics International Limited)
• Original Assignee: Flextronics America LLC (Flextronics International Limited)
• Inventors: Zsombory, Sandor, Polityka, Gregory A.
• Primary Examiner(s): Shaawat, Mussa A
• Assistant Examiner(s): Wong, Yuen
• Application Number:
  US14/489,714
• Publication Number:
  US 20160082957A1
• Time in Patent Office: 537 Days
• US Class Current: 1/1
• CPC Class Codes: B60Q 9/00 Arrangement or adaptation of signal devices not provided for in one of main groups B60Q1/00 - B60Q7/00 , e.g. haptic signalling
• CPC Class Codes: B60W 2400/00 Indexing codes relating to detected, measured or calculated conditions or factors
• CPC Class Codes: B60W 2420/503 Hall effect or magnetoresistive, i.e. active wheel speed sensors
• CPC Class Codes: B60W 30/12 Lane keeping
• CPC Class Codes: G05D 1/0261 using magnetic plots
• CPC Class Codes: G08G 1/09623 Systems involving the acquisition of information from passive traffic signs by means mounted on the vehicle G08G1/0967 takes precedence
• CPC Class Codes: G08G 1/0967 Systems involving transmission of highway information, e.g. weather, speed limits transmission of navigation instructions to the vehicle G08G1/0968
• CPC Class Codes: G08G 1/167 Driving aids for lane monitoring, lane changing, e.g. blind spot detection

Abstract

Described herein is a system and method that recognizes vehicle lane departure in road conditions affected by environmental conditions. The system uses magnetic field flux detection to determine if a vehicle is departing from a projected vehicle trajectory or a determined vehicle position between lanes. A magnetic material is applied to the stripes painted on road surfaces or on other applicable lane boundary indicators. The system uses magnetic field flux sensors or Hall Effect sensors mounted in the vehicle to recognize changes in magnetic field flux from the magnetized road stripe. These changes in magnetic field flux are interpreted by the system to determine whether alarms should be initiated for vehicle lane departure.

Claims

1. A vehicle lane departure system, comprising:

a plurality of magnetic field detectors positioned on a vehicle to detect magnetic fields from magnetic road markers on a road;

an electronic control unit (ECU) connected to the plurality of magnetic field detectors, wherein the ECU initiates an event when at least certain magnetic field detectors of the plurality of magnetic field detectors detect a magnetic field with respect to a magnetic road marker;

a front magnetic field detector of the magnetic field to start a warning time window;

a rear magnetic field detector to start an alarm time window when the rear magnetic field detector detects another magnetic field in the warning time window; and

a second front magnetic field detector sends an alarm when the second front magnetic field detector detects the magnetic field in the alarm time window,

wherein the front magnetic field detector, the rear magnetic field detector and the second front magnetic field detector are the at least the certain magnetic field detectors of the plurality of magnetic field detectors and the event is an alarm.

2. The vehicle lane departure system of claim 1, wherein at least one predetermined action occurs in response to the event.

3. The vehicle lane departure system of claim 1, wherein the event is a warning zone event when the at least certain magnetic field detectors of the plurality of magnetic field detectors is a front magnetic field detector and a rear magnetic field detector.

4. The vehicle lane departure system of claim 1, wherein the event is an alarm zone event when the at least certain magnetic field detectors of the plurality of magnetic field detectors is at least two front magnetic field detectors and a rear magnetic field detector.

5. The vehicle lane departure system of claim 1, wherein a length associated with the magnetic road markers corresponds to a predetermined speed zone.

6. The vehicle lane departure system of claim 1, wherein a length associated with the magnetic road markers corresponds to deceleration zone.

7. The vehicle lane departure system of claim 1, wherein a pattern of the magnetic road markers corresponds to an upcoming traffic sign or condition.

8. A method for vehicle lane departure, the method comprising:

providing a plurality of magnetic field detectors for positioning on a vehicle to detect magnetic fields from magnetic road markers on a road;

providing an electronic control unit (ECU) connected to the plurality of magnetic field detectors;

initiating by the ECU an event when at least certain magnetic field detectors of the plurality of magnetic field detectors detect a magnetic field with respect to a magnetic road marker;

detecting a magnetic field by a front magnetic field detector;

starting a warning time window;

starting an alarm time window when a rear magnetic field detector detects another magnetic field in the warning time window; and

sending an alarm when a second front magnetic field detector detects the magnetic field in the alarm time window,

wherein the front magnetic field detector, the rear magnetic field detector and the second front magnetic field detector are the at least certain magnetic field detectors of the plurality of magnetic field detectors and the event is an alarm.

9. The method of claim 8, further comprising:

performing at least one predetermined action in response to the event.

10. The method of claim 8, wherein the event is a warning zone event when the at least certain magnetic field detectors of the plurality of magnetic field detectors is at least one front magnetic field detector and a rear magnetic field detector.

11. The method of claim 8, wherein the event is an alarm zone event when the at least certain magnetic field detectors of the plurality of magnetic field detectors is at least two front magnetic field detectors and a rear magnetic field detector.

12. The method of claim 8, wherein a length associated with the magnetic road markers corresponds to a predetermined speed zone.

13. The method of claim 8, wherein a length associated with the magnetic road markers corresponds to deceleration zone.

14. The method of claim 8, wherein a pattern of the magnetic road markers corresponds to an upcoming traffic sign or condition.

15. The method of claim 8, wherein a warning is sent when the alarm time window expires without additional magnetic field detections and the event is a warning.

16. The method of claim 8, wherein the event are corrective actions taken by user or the vehicle to correct vehicle lane departure.

17. The method of claim 8, wherein the event are actions taken by a user or the vehicle in response to the magnetic road markers being associated with traffic signs or conditions.