Method of selecting a preceding vehicle, a preceding vehicle selecting apparatus, and a recording medium for selecting a preceding vehicle

• US 20010037165A1
• Filed: 03/26/2001
• Published: 11/01/2001
• Est. Priority Date: 03/30/2000
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Morikawa, Katsuhiro, Shirai, Noriaki
• Granted Patent: US 6,484,087 B2
• Time in Patent Office: Days
• US Class Current: 701/1
• 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 30/16 Control of distance between vehicles, e.g. keeping a distance to preceding vehicle
• CPC Class Codes: G01S 17/42 Simultaneous measurement of distance and other co-ordinates indirect measurement G01S17/46
• CPC Class Codes: G01S 17/931 of land vehicles
• CPC Class Codes: G01S 2013/9323 Alternative operation using light waves
• CPC Class Codes: G08G 1/165 for passive traffic, e.g. including static obstacles, trees
• 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

The radius of the curvature of the lane on which a subject vehicle is traveling, is calculated in accordance with the turning condition of the subject vehicle and the velocity of the subject vehicle is obtained on the basis of the steering angle, and the yaw rate. An instantaneous probability of the same lane that the recognized object target exists on the same lane is calculated. In this operation, the instantaneous probability is compensated. That is, the road shape is recognized with delineator or the like. The instantaneous probability of the same lane is compensated on the basis of the recognized road shape. The probability of the same lane is calculated after a predetermined filtering process with the compensated instantaneous probability of the same lane. The preceding vehicle is selected on the basis of the probability of the same lane.

Claims

1. A method of selecting one of recognized objects as a preceding vehicle of a subject vehicle, comprising the steps of:

recognizing said objects in front of said subject vehicle;

obtaining relative positions and relative velocities of said recognized objects;

classifying said objects into stationary objects and moving objects on the basis of relative velocities of said objects to said subject vehicle;

calculating a curvature of the lane on which said subject vehicle is traveling, on the basis of a turning condition and the velocity of said subject vehicle;

calculating a probability that each of said moving objects travels on the same lane as said subject vehicle on the basis of said curvature and said relative position of each of said moving objects;

recognizing a shape of the road, including the lane, in front of said subject vehicle, on the basis of distances to said stationary objects and angles of said stationary objects in the width direction of said subject vehicle and detecting a degree of recognizing said shape on the basis of said relative positions of said stationary objects and each of said moving objects;

detecting a possibility that each of said moving objects exists on the same lane as said subject vehicle on the basis of the recognized shape of the road and said degree;

calculating a compensation value for compensating said probability on the basis of the detected possibility;

compensating said probability with said compensation value; and

selecting one of said moving objects as the preceding vehicle on the basses of the compensated probability.

2. A preceding vehicle selecting apparatus for a vehicle comprising:

turning detection means for detecting a turning condition of a subject vehicle;

curvature calculation means for calculating a curvature of the lane on which said subject vehicle is traveling, on the basis of the detected turning condition and a velocity of said vehicle;

radar means for emitting a transmission signal within a predetermined angle range, in front of said vehicle, extending in a width direction of said vehicle and detecting distances to objects reflecting said transmission signal and angles of said object in said width direction of on the basis of the reflected transmission signal;

object recognizing means for obtaining relative positions and relative velocities of said objects to said vehicle on the basis of the distances and the angles in said width direction from said radar means and classifying said objects into stationary objects and moving objects on the basis of said relative velocities;

the-same-lane probability calculation means for calculating a probability that each of said moving objects exists on the same lane as said subject vehicle, on the basis of the curvature from said curvature calculation means and the relative position of each of said moving objects from said object recognition means;

road shape recognition means for extracting a part of said stationary objects which are effective for recognizing a shape of said road on the basis of said relative positions of said stationary objects, recognizing a shape of said road in front of said subject vehicle on the basis of said relative positions of said extracted stationary objects, and detecting a degree that said shape has been recognized in accordance with said relative positions of said stationary objects and each of said moving objects;

the-same-lane judging means for judging the possibility that each of said moving objects exists on the same lane as said vehicle on the basis of said recognized road shape and said degree;

compensation value calculation means for calculating a compensation value for compensating said probability of each of said moving objects on the basis of the judging result by said the-same-lane judging means;

compensation means for compensating said probability from said the-same-lane probability calculation means with said compensation value for each of said moving objects; and

preceding vehicle selection means for selecting the preceding vehicle of said vehicle from said moving objects on the basis of probabilities from said compensation means.

3. A preceding vehicle selection apparatus as claimed in

claim 2

, wherein said the-same-lane judging means further judges whether said degree is such that said the-same-lane judging means will incorrectly judge the possibility in accordance with the recognized shape of said road, and when said the-same-lane judging means judges that said degree is such that said the-same-lane judging means will incorrectly judge the possibility, said compensation value calculation means makes said compensation value zero.

4. A preceding vehicle selection apparatus as claimed in

claim 2

, wherein said the-same-lane judging means further judges whether said degree is such that said shape of said road is recognized only at the range nearer than each of said moving objects, and when said the-same-lane judging means judges that said degree is such that said shape of said road is recognized only at the range nearer than each of said moving objects, said compensation value calculation means makes the absolute value of said compensation value for each of said moving objects relatively small.

5. A preceding vehicle selection apparatus as claimed in

claim 2

, wherein said the-same-lane judging means further judges whether said degree is such that said shape of said road is recognized only at the range nearer than each of said moving objects, and when said the-same-lane judging means judges that said degree is such that said shape of said road is recognized only at the range nearer than each of said moving objects, said compensation value calculation means makes the absolute value of said compensation value for said one of said moving objects relatively small in accordance with a relative distance of said recognized shape determined with relative positions of said part of said stationary objects.

6. A preceding vehicle selection apparatus as claimed in

claim 2

, wherein said the-same-lane judging means further judges whether each of said moving object exists around one of edge of said road, and when said the-same-lane judging means judges that each of said moving object exists around one of edge of said road, said compensation value calculation means makes said compensation value relatively large in the negative direction

7. A preceding vehicle selection apparatus as claimed in

claim 2

, wherein said the-same-lane judging means judges the possibility that each of said moving objects exists on the same lane with reference to relations of said relative position of each of said moving objects and relative positions of said part of stationary objects.

12. A preceding vehicle selection apparatus as claimed in

claim 2

, wherein the-same-lane judging means detects a relative velocity vector of said part of stationary objects which are effective for recognizing a shape of said road, obtains a circle of which a tangent line vector corresponds to said relative velocity vector, and judges the possibility on the basis of said circle.

8. A preceding vehicle selection apparatus as claimed in 2, wherein said road shape reorganization means recognizes edges of said road, and said the-same-lane judging means judges the possibility that each of said moving objects exists on the same lane as said vehicle on the basis of each of said recognized edges and said degree, and judges a priority of said possibility on the basis of said degree every said recognized edge, and said compensation value calculation means calculates a compensation value for compensating said probability of each of said moving objects on the basis of the judging result of said the-same-lane judging means of which said priority judged for one of said recognized edges is higher than that for the other of said recognized edges.

9. A preceding vehicle selection apparatus as claimed in

claim 8

, wherein said the-same-lane judging means further judges whether said degree is such that said shape of said road is recognized only at the range nearer than each of said moving objects, and when said the-same-lane judging means judges that said degree is such that said shape of said road is recognized only at the range nearer than each of said moving objects, said the-same-lane judging means judges said priority of said possibility to be relative low priority.

10. A preceding vehicle selection apparatus as claimed in

claim 8

, wherein said the-same-lane judging means further judges whether each of said moving object exists around one of edge of said road, and when said the-same-lane judging means judges that each of said moving object exists around one of edges of said road, said the-same-lane judging means judges said priority to be relatively high.

11. A preceding vehicle selection apparatus as claimed in

claim 10

, wherein said the-same-lane judging means judges the priority that each of said moving objects exists on the same lane with reference to relations of said relative position of each of said moving objects and relative positions of said part of stationary objects.

13. A recoding medium readable by a computer for recording programs for a preceding vehicle selection apparatus for a vehicle comprising:

turning detection means for detecting a turning condition of a subject vehicle;

curvature calculation means for calculating a curvature of the lane on which said subject vehicle is traveling, on the basis of the detected turning condition and a velocity of said vehicle;

radar means for emitting a transmission signal within a predetermined angle range, in front of said vehicle, extending in a width direction of said vehicle and detecting distances to objects reflecting said transmission signal and angles of said object in said width direction of on the basis of the reflected transmission signal;

object recognizing means for obtaining relative positions and relative velocities of said objects to said vehicle on the basis of the distances and the angles in said width direction from said radar means and classifying said objects into stationary objects and moving objects on the basis of said relative velocities;

the-same-lane probability calculation means for calculating a probability of existence of each of said moving objects on the same lane as said subject vehicle on the basis of the curvature from said curvature calculation means and the relative positions of each of said moving objects from said object recognition means;

road shape recognition means for extracting a part of said stationary objects which are effective for recognizing a shape of said road on the basis of said relative positions of said stationary objects, recognizing a shape of said road on the basis of said relative positions of said extracted stationary objects, and detecting a degree that said shape has been recognized, in accordance with said relative positions of said stationary objects and each of said moving objects;

the-same-lane judging means for judging the possibility that each of said moving objects exists on the same lane as said vehicle on the basis of said recognized road shape and said degree;

compensation value calculation means for calculating a compensation value for compensating said the-same-lane probability of each of said moving objects on the basis of the judging result by said the-same-lane judging means;

compensation means for compensating said the-same-lane probability from said the-same-lane probability calculation means with said compensation value for each of said moving objects from said compensation value calculation means; and

preceding vehicle selection means for selecting the preceding vehicle of said vehicle from said moving objects on the basis of the-same-lane probabilities from said compensation means.