Off-lane alarm apparatus

• US 5,661,472 A
• Filed: 01/26/1996
• Issued: 08/26/1997
• Est. Priority Date: 01/31/1995
• Status: Expired due to Term

• Current Assignee: Isuzu Motors Limited
• Original Assignee: Isuzu Motors Limited
• Inventors: Koshizawa, Toshifumi
• Primary Examiner(s): Swarthout, Brent A.
• Assistant Examiner(s): TRIEU, VAN THANH
• Application Number:
  US08/592,519
• Time in Patent Office: 578 Days
• Field of Search: 340/901, 340/903, 340/904, 340/905, 340/435, 340/937, 348/113, 348/118, 348/148, 348/149, 348/169, 364/424.01, 364/424.02, 364/436, 364/460, 364/461
• US Class Current: 340/901
• CPC Class Codes: B60T 2201/08 Lane monitoring; Lane Keeping Systems
• CPC Class Codes: B60T 2201/082 using alarm actuation
• CPC Class Codes: B60T 2201/089 using optical detection
• CPC Class Codes: G05D 1/0246 using a video camera in combination with image processing means

Abstract

An off-lane alarm apparatus quantizes an image signal provided from a line camera mounted on a car roof is into a corresponding binary image by an image processing device to detect a lane on a road surface, so that an alarm is generated when an off-lane state of the car from the lane is detected. After mounting a line camera on a car, markers preset at predetermined positions outside of the car are shot and preliminarily stored as binary image signals and the positional information is used as car side positional information for alarm determinations.

Claims

1. An off-lane alarm apparatus wherein an image signal provided from a line camera mounted on a car is quantized into a corresponding binary image by an image processing device to detect a lane on a road surface whereby an alarm is generated when an off-lane state of said car from said lane is detected, said apparatus comprising a memory;

said image processing device having preliminarily stored, in said memory, horizontal position data as car side position data of binary images of markers positioned at a predetermined outside point corresponding to a permissible error in the pan direction of said line camera on both side ends of said car and shot as said image signal by said line camera positioned at a predetermined front center of said car; and

said image processing device generating said alarm on the basis of a relationship between the horizontal position data of the detected lane and the position data of both side ends of said car.

2. An off-lane alarm apparatus as claimed in claim 1, wherein said memory comprises an EEPROM with electrically erasing and writing functions.

3. An off-lane alarm apparatus as claimed in claim 1, further comprising a setting switch, wherein said image processing device has preliminarily stored, in said memory, the horizontal position data of said markers, on the basis of an ON/OFF state of said setting switch.

4. An off-lane alarm apparatus as claimed in claim 3, wherein said setting switch comprises two switches respectively provided for the right and the left markers, with each of said two switches independently providing as an output its ON/OFF state for said image processing device.

5. An off-lane alarm apparatus wherein an image signal provided from a line camera mounted on a car is quantized into a corresponding binary image by an image processing device to detect a lane on a road surface whereby an alarm is generated when an off-lane state of said car from said lane is detected, said apparatus comprising a memory;

said image processing device having preliminarily stored, in said memory, horizontal position data as car side position data of binary images of desired actual lanes as reference markers along which said car is running, shot as said image signal by said line camera positioned at a predetermined front center of said car; and

said image processing device generating said alarm on the basis of a relationship between the horizontal position data of the detected lane and the position data of both side ends of said car.

6. An off-lane alarm apparatus as claimed in claim 5, wherein said memory comprises an EEPROM with electrically erasing and writing functions.

7. An off-lane alarm apparatus as claimed in claim 5, further comprising a setting switch, wherein said image processing device has preliminarily stored, in said memory, the horizontal position data of said markers, on the basis of an ON/OFF state of said setting switch.

8. An off-lane alarm apparatus as claimed in claim 7, wherein said setting switch comprises two switches respectively provided for the right and the left markers, with each of said two switches independently providing as an output its ON/OFF state for said image processing device.

9. An off-lane alarm apparatus for a vehicle, comprising:

a camera mounted on the vehicle to produce an image signal;

an image processing device, coupled to said camera, to process the image signal to detect a lane on a road surface;

a memory, coupled to said image processing device, to preliminarily store horizontal position data corresponding to markers positioned at predetermined points with respect to the sides of the vehicle and corresponding to a permissible error in a pan direction of said camera, said image processing device generating an alarm signal on the basis of detected horizontal position data which is based on the preliminarily stored horizontal position data and the image signal processed by said image processing device.

10. A method for detecting when a vehicle is off-lane, comprising:

producing an image signal by a camera mounted on the vehicle;

preliminarily storing horizontal position data corresponding to markers positioned at predetermined points with respect to the sides of a vehicle and corresponding to a permissible error in a pan direction of the camera; and

generating an alarm signal based on the preliminarily stored horizontal position data and the image signal.