Vehicle control method and vehicle warning method

• US 20020032515A1
• Filed: 11/08/2001
• Published: 03/14/2002
• Est. Priority Date: 06/28/1999
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Nakamura, Mitsuru, Bai, Jie
• Granted Patent: US 6,567,737 B2
• Time in Patent Office: Days
• US Class Current: 701/96
• CPC Class Codes: B60K 31/0008 including means for detecting potential obstacles in vehicle path
• CPC Class Codes: B60W 2050/143 Alarm means
• 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 2556/50 of positioning data, e.g. GPS [Global Positioning System] data
• CPC Class Codes: B60W 30/16 Control of distance between vehicles, e.g. keeping a distance to preceding vehicle
• CPC Class Codes: G01S 13/931 of land vehicles
• CPC Class Codes: G01S 2013/93185 Controlling the brakes
• 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 2013/9325 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 7/403 in azimuth, i.e. in the horizontal plane
• CPC Class Codes: G01S 7/4082 using externally generated reference signals, e.g. via remote reflector or transponder

Abstract

In order to occur a collision warning to prevent the collision in accurate by detecting the preceding vehicle or target, a vehicle lane position estimation device comprising a means for measuring a distance between said host vehicle and said preceding vehicle or a oncoming vehicle, a direction angle from said host vehicle, an angular velocity and a velocity of said host vehicle, a means for calculating lateral and longitudinal distance between said host vehicle and said preceding vehicle or said oncoming vehicle, a means for capturing a front stationary object, a means for obtaining movement of the preceding vehicle or position of the oncoming vehicle, and a means to estimate a lane position of said front stationary object from a relationship of the stationary object being captured and the preceding vehicle being obtained and a positional relationship with the oncoming vehicle.

Claims

1. A vehicle control method comprising the steps of

detecting a velocity and angular velocity of a host vehicle, and a distance and a direction from said host vehicle to a preceding vehicle or a target,

calculating a next distance from said host vehicle to said preceding vehicle or said target based on said velocity, angular velocity and said direction detected in the former step, and

controlling said host vehicle so as to decelerate said host vehicle when said next distance is smaller than a predetermined value.

2. A vehicle control method as defined in claim 1, said vehicle control method characterized in that

said predetermined value is smaller than a half of a vehicle lane.

4. A vehicle control method as defined in claim 1, said vehicle control method characterized in that

said predetermined value is samller than a half of a vehicle lane.

3. A vehicle warning method comprising the steps of

detecting a velocity and angular velocity of a host vehicle, and a distance and a direction from said host vehicle to a preceding vehicle or a target,

calculating a next distance from said host vehicle to said preceding vehicle or said target based on said velocity, angular velocity and said direction detected in the former step, and

generating a warning when said next distance is smaller than a predetermined value.

5. A vehicle lane position estimation device for capturing a preceding vehicle or a target by searching forward of an host vehicle and estimating vehicle lane position thereof, said vehicle lane position estimation device comprising

a means for measuring a distance TR between said host vehicle and said preceding vehicle or said target, a direction angle α

from said host vehicle, an angular velocity Ws and a velocity Vs of said host vehicle,

one vehicle lane sensing means for obtaining a lane Ly of a road,

a means for calculating a lateral displacement TC between said host vehicle and said preceding vehicle or said target, a longitudinal displacement TD therebetween and a curvature radius R of said host vehicle based on a following equation

T_C=T_R sin α

, T_D=T_R cos α

, R=Vs/Ws,

a means for calculating lateral distance Δ

R between said host vehicle and said preceding vehicle or said target based on a following equation,

Δ

R={square root}{square root over ((R−

Tc)2+Tp2−

R)} 

 

(Equation

     1)

a means for comparing Ly/2 with Δ

R, and

a means for judging said preceding vehicle or said target to be in a vehicle lane of said host vehicle when 1 Δ

R1<

Ly/2.

6. A vehicle lane position estimation device as defined in claim 5, further comprising

a means for judging whether a curve of said road is a transition curve section where a curvature radius thereof changes every moment sometimes, or a maximum curve section where said curvature radius does not changes, and

a means for correcting a curvature radius Rs of said host vehicle used for correcting said curvature radius Rf of said preceding vehicle to be smaller than a predetermined value when a transition curve is in an introduction part of the curve, and for correcting said curvature radius Rs to be larger than said predetermined value when said transition curve is in an rear part of the curve.

7. A vehicle lane position estimation device as defined in claim 5, further comprising

a means for obtaining a judgment position of a vehicle lane of said host vehicle by estimating a vehicle lane position of plural said preceding vehicle and making a vehicle lane judgment position of said preceding vehicle offset towards right or left according to said vehicle lane position estimated.

8. A vehicle lane position estimation device as defined in claim 5, wherein

a millimeter wave radar and a gyro sensor are used as said means for measuring.

9. A vehicle lane position estimation device as defined in claim 5, wherein

a steering sensor and a gyro sensor are used as said means for measuring.

10. A vehicle lane position estimation device as defined in claim 5, wherein

a CCD camera and a navigation device having a route guidance function are used as said means for measuring.

11. A vehicle lane position estimation device as defined in claims 5 to 10, further comprising

a means obtaining a distance of the vehicles from said preceding vehicle, and

a means for warning when said distance becomes a predetermined distance.

13. A vehicle lane position estimation device as defined in claim 12, further comprising

a means for calculating lateral distance Δ

R between said host vehicle and said forward stationary object based on following equations

T_C=T_R sin α

, T_D=T_R cos α

, R=Vs/Ws

and

Δ

R={square root}{square root over ((R−

Tc)2+Tp2−

R)} 

 

(Equation

     1)

wherein

T is a distance between said host vehicle and said forward stationary object, a angle from said host vehicle, Ws velocity of said host vehicle, Vs velocity of said host vehicle, Tc lateral displacement, TD longitudinal displacement, and R curvature radius of said host vehicle.

14. A vehicle lane position estimation device as defined in claim 12 or 13, further comprising

a means for recognizing whether said forward stationary object is an object on the road such as an overhead bridge.

12. A vehicle lane position estimation device for estimating a position of a vehicle lane of a stationary object (a forward stationary object) to be located before an host vehicle, comprising

a means for measuring a distance between said host vehicle and said preceding vehicle or an oncoming vehicle, a direction angle from said host vehicle, an angular velocity and a velocity of said host vehicle,

one vehicle lane sensing means for obtaining a vehicle lane of a road,

a means for calculating a lateral displacement between said host vehicle and said preceding vehicle or said oncoming vehicle, a longitudinal displacement therebetween and a curvature radius of said host vehicle,

a means for capturing a forward stationary object,

a means for obtaining a movement of said preceding vehicle or a position of said oncoming vehicle,

a means for estimating a vehicle lane position of said forward stationary object from a movement relationship of said preceding vehicle obtained and said forward stationary object captured or a position relationship with said oncoming vehicle, and

a means for warning when said forward stationary object is in a vehicle lane of said host vehicle.