Obstacle warning system for a vehicle

• US 5,751,211 A
• Filed: 12/27/1996
• Issued: 05/12/1998
• Est. Priority Date: 12/28/1995
• Status: Expired due to Term

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Nishimura, Takao, Shirai, Noriaki, Hibino, Katsuhiko
• Primary Examiner(s): Mullen, Thomas
• Assistant Examiner(s): Tong, Nina
• Application Number:
  US08/777,196
• Time in Patent Office: 501 Days
• Field of Search: 340/435, 340/436, 340/901, 340/903, 340/904, 342/70, 342/71, 367/909, 367/112, 367/96, 367/97, 367/107, 364/460, 364/461, 364/426.04, 180/167, 180/168, 180/169
• US Class Current: 340/435
• CPC Class Codes: B60K 28/10 responsive to conditions relating to the vehicle
• CPC Class Codes: B60W 10/04 including control of propulsion units
• CPC Class Codes: B60W 10/10 including control of change-speed gearings
• CPC Class Codes: B60W 2552/20 Road profile, i.e. the change in elevation or curvature of a plurality of continuous road segments
• CPC Class Codes: B60W 2552/30 Road curve radius
• CPC Class Codes: B60W 2554/00 Input parameters relating to objects
• CPC Class Codes: B60W 2554/20 Static objects
• CPC Class Codes: B60W 2554/802 Longitudinal distance
• CPC Class Codes: B60W 30/18 Propelling the vehicle
• CPC Class Codes: B60W 30/1819 Propulsion control with control means using analogue circuits, relays or mechanical links
• CPC Class Codes: G01S 13/44 Monopulse radar, i.e. simultaneous lobing
• CPC Class Codes: G01S 13/931 of land vehicles
• CPC Class Codes: G01S 17/931 of land vehicles
• CPC Class Codes: G01S 2013/93185 Controlling the brakes
• CPC Class Codes: G01S 2013/9319 Controlling the accelerator
• CPC Class Codes: G01S 2013/932 using own vehicle data, e.g. ground speed, steering wheel direction
• CPC Class Codes: G01S 2013/9321 Velocity regulation, e.g. cruise control
• CPC Class Codes: G01S 2013/9324 Alternative operation using ultrasonic waves
• CPC Class Codes: G01S 2013/9325 for inter-vehicle distance regulation, e.g. navigating in platoons
• CPC Class Codes: G01S 2013/93271 in the front of the vehicles
• CPC Class Codes: G01S 2013/9329 : cooperating with reflectors or transponders
• CPC Class Codes: G03C 1/16 : with one CH group
• CPC Class Codes: Y10S 367/909 : Collision avoidance

Abstract

As provided here, an obstacle warning system for a vehicle is capable of issuing an alarm accurately according to the curved state of a road. When the road is curved, the system sets the correction time counter on the basis of the following conditions: whether or not the curvature radius of the curved road is small; whether or not a guardrail is detected immediately ahead of the vehicle; whether or not an erroneously-recognized object, such as a set of guardrail reflectors exhibiting large relative acceleration is immediately ahead of the vehicle; and whether or not the number of obstacles recognized reaches a value indicating that the vehicle is approaching a curved section of the road. When a stationary object enters the field of view indicating that there is a possibility of a collision, the obstacle warning system corrects the warning distance in response to the value of the correction time counter, thus making it possible to avoid a false alarm during cornering.

Claims

1. An obstacle warning system for a vehicle, comprising:

obstacle detecting means for detecting a distance to an obstacle and an angle of the obstacle within a forward detection zone defined by a given angle in a width direction of the vehicle;

warning means for issuing an alarm when the obstacle detected by said obstacle detecting means satisfies a given warning condition;

guardrail detecting means for detecting a guardrail on the basis of the distance to the obstacle and the angle of the obstacle detected by said obstacle detecting means when the obstacle detected by said obstacle detecting means extends a long distance along a forward direction of the vehicle;

curved state detecting means for detecting a curved state of a road on the basis of a position of the guardrail detected by said guardrail detecting means; and

warning condition correcting means for correcting the warning condition on the basis of the curved state of the road detected by said curved state detecting means.

2. An obstacle warning system as set forth in claim 1, further comprising curvature radius calculating means for calculating a curvature radius from a path or a locus of the obstacle detected by said obstacle detecting means when the obstacle is substantially stationary,

wherein said curved state detecting means detects the curved state on the basis of both the position of the guardrail detected by said guardrail detecting means and the curvature radius provided by said curvature radius calculating means.

3. An obstacle warning system as set forth in claim 1, wherein said curved state detecting means detects the curved state on the basis of both the position of the guardrail detected by said guardrail detecting means and whether or not a plurality of obstacles detected by said obstacle detecting means exceeds a given value.

4. An obstacle warning system as set forth in claim 1, further comprising:

acceleration calculating means for calculating a relative acceleration between the vehicle and the obstacle detected by said obstacle detecting means; and

erroneously-recognized object detecting means for detecting and recognizing the obstacle as an erroneously-recognized object when the relative acceleration provided by said acceleration calculating means is out of a given range,

wherein said curved state detecting means detects the curved state on the bases of both the position of the guardrail and whether or not the erroneously-recognized object is detected in a given detection zone defined ahead of the vehicle.

5. An obstacle warning system for a vehicle, comprising:

obstacle detecting means for detecting a distance to an obstacle and an angle of the obstacle within a forward detection zone defined by a given angle in a width direction of the vehicle;

warning means for issuing an alarm when the obstacle detected by said obstacle detecting means satisfies a given warning condition;

guardrail detecting means for detecting a guardrail on the basis of the distance to the obstacle and the angle of the obstacle detected by said obstacle detecting means when the obstacle detected by said obstacle detecting means extends a long distance along a forward direction of the vehicle;

curved state detecting means for detecting a curved state of a road through determination as to whether or not the guardrail detected by said guardrail detecting means is located in a predetermined area in front of said vehicle; and

warning condition correcting means for correcting the warning condition on the basis of the curved state of the road detected by said curved state detecting means.

6. An obstacle warning system as set forth in claim 5, further comprising:

curvature radius calculating means for calculating a curvature radius from a path or a locus of the obstacle detected by said obstacle detecting means when the obstacle is substantially stationary,

wherein said curved state detecting means detects the curved state on the basis of both the position of the guardrail provided by said guardrail detecting means and the curvature radius provided by said curvature radius calculating means.

7. An obstacle warning system as set forth in claim 5,

wherein said curved state detecting means detects the curved state on the basis of both the position of the guardrail detected by said guardrail detecting means and whether or not a plurality of obstacles detected by said obstacle detecting means exceeds a given value.

8. An obstacle warning system as set forth in claim 5, further comprising:

acceleration calculating means for calculating a relative acceleration between the vehicle and the obstacle detected by said obstacle detecting means; and

erroneously-recognized object detecting means for detecting and recognizing the obstacle as an erroneously-recognized object when the relative acceleration provided by said acceleration calculating means is out of a given range,

wherein said curved state detecting means detects the curved state on the basis of both the position of the guardrail detected by said guardrail detecting means and whether or not the erroneously-recognized object is detected in a given detection zone defined ahead of the vehicle.