Vehicle location estimation apparatus and vehicle location estimation method

Patent metadata

Field	Value
Publication number	US-9734718-B2
Application number	US-201314647985-A
Country	US
Kind code	B2
Filing date	Nov 28, 2013
Priority date	Nov 30, 2012
Publication date	Aug 15, 2017
Grant date	Aug 15, 2017

Abstract

An azimuth of the direction of travel of the host vehicle is acquired, a radius of the road on which the host vehicle is traveling is estimated, a location of another vehicle is acquired, an azimuth of the direction of travel of the other vehicle is acquired, the other vehicle is positioned on a coordinate system, an origin of which is the host vehicle, and an axis of which is the estimated road radius in the direction of travel of the host vehicle, and determination is made on whether or not the other vehicle is on the same course as the host vehicle by taking account of the width of the course, location error, azimuth error, error in the estimated road radius, error due to drift of the vehicle, and change in the curvature of the course.

First claim

The invention claimed is:

1. A vehicle location estimation apparatus for estimating a location of an other vehicle in the periphery of a host vehicle,
the vehicle location estimation apparatus comprising:
an azimuth sensor configured to acquire an azimuth of a direction of travel of the host vehicle;
a receiver configured to:
receive the location of the other vehicle, and
receive an azimuth of a travel path direction in which the other vehicle is travelling; and
an ECU configured to:
estimate a curvature radius of a road on which the host vehicle is traveling;
arrange the other vehicle on a coordinate system, an origin of which is a position of the host vehicle, and an axis of which is the direction of travel in which the host vehicle is travelling, and
determine a lane on which the other vehicle is travelling, a lane on which the host vehicle is travelling, the travel path direction in which the other vehicle, and the travel path direction in which the host vehicle is travelling, by taking account at least one from among a width of the road, error in the received location of the other vehicle, error in the estimated curvature radius of the road, change in a curvature of the direction of travel of the host vehicle, azimuth error of the host vehicle and the other vehicle, error in an azimuth and a curvature radius of the direction of travel of the host vehicle due to drift of the host vehicle and the other vehicle,
set a location threshold value and an azimuth threshold value, and
determine whether or not the lane on which the other vehicle is traveling is the same as the lane on which the host vehicle is travelling and the travel path direction in which the other vehicle is travelling is the same as the direction of travel in which the host vehicle is travelling, by comparing the location of the other vehicle with the location threshold value, and also comparing the azimuth of the other vehicle with the azimuth threshold value.

2. The vehicle location estimation apparatus according to claim 1 , wherein the ECU is further configured to:
acquire a travel trajectory of the host vehicle; and
acquire a travel distance of the host vehicle along the travel trajectory of the host vehicle,
determine if the other vehicle is travelling in the rear of the host vehicle,
arrange, in response to determining whether or not the lane on which the other vehicle in the rear of the host vehicle is travelling is the same as the lane on which the host vehicle is travelling and the travel path direction in which the other vehicle is travelling is the same as the travel path direction in which the host vehicle is travelling, the other vehicle in the rear of the host vehicle on a coordinate system, an origin of which is a position of the host vehicle, and an axis of which is the travel trajectory of the host vehicle in the rear of the host vehicle; and
determine whether or not the lane on which the other vehicle is travelling in the rear is the same as the lane on which the host vehicle is travelling and the travel path direction in which the other vehicle is travelling is the same as the travel path direction in which the host vehicle is travelling, by taking account of at least on from among the width of the road, error in the received location of the other vehicle, and drift error per travel distance on the travel trajectory.

3. The vehicle location estimation apparatus according to claim 1 , further comprising:
a GPS configured to detect an absolute location of the host vehicle, wherein the ECU is further configured to:
implement conversion from a coordinate system based on the absolute location to a relative coordinate system, the origin of which is the position of the host vehicle, wherein
an object of same-course determination is an other vehicle which is in vehicle-to-vehicle communications with the host vehicle;
acquire the absolute azimuth of the host vehicle;
acquire the absolute location of the other vehicle by vehicle-to-vehicle communications;
acquire the absolute azimuth of the other vehicle by vehicle-to-vehicle communications; and
convert the absolute location and the absolute azimuth of the other vehicle to the relative coordinate system, an origin of which is the position of the host vehicle.

4. The vehicle location estimation apparatus according to claim 1 , further comprising:
a camera configured to capture an image of the periphery of the host vehicle, wherein the ECU is further configured to:
detect a lane in which the host vehicle is traveling on the basis of the image captured by the camera;
calculate a curvature of the detected lane;
calculate a change in the calculated curvature; and
determine whether or not the lane on which the other vehicle is travelling is the same as the lane on which the host vehicle is travelling and the travel path direction in which the other vehicle is travelling is the same as the travel path direction in which the host vehicle is travelling, by using the calculated curvature and the change in the calculated curvature.

5. The vehicle location estimation apparatus according to claim 1 , further comprising:
a vehicle speed sensor configured to detect a speed of the host vehicle, wherein the ECU is further configured to:
judge whether or not the host vehicle is traveling in free flowing traffic;
estimate a road alignment corresponding to the detected vehicle speed, in response to a determination that the host vehicle is traveling in free flowing traffic; and
determine whether or not a the lane on which the other vehicle travels is the same as the lane on which the host vehicle travels and the travel path direction in which the other vehicle is travelling is the same as the travel path direction in which the host vehicle is travelling, by using the estimated road alignment.

6. The vehicle location estimation apparatus according to claim 5 , wherein the ECU is further configured to:
record the vehicle speed the host vehicle is traveling in free flowing traffic; and
estimate the road alignment corresponding to the vehicle speed recorded the last time that the host vehicle was judged to be traveling in free flowing traffic, in response to the ECU judging that the host vehicle is not traveling in free flowing traffic.

7. The vehicle location estimation apparatus according to claim 5 , wherein the ECU is further configured to:
acquire a time between the host vehicle and the other vehicle traveling in front of the host vehicle; and
judge whether or not the host vehicle is traveling in free flowing traffic on the basis of the detected vehicle speed and the acquired time between vehicles.

8. The vehicle location estimation apparatus according to claim 1 , wherein the ECU is further configured to control the host vehicle to avoid the other vehicle based on the determination of the travel path direction of the other vehicle.

9. A vehicle location estimation method for estimating a location of an other vehicle in the periphery of a host vehicle,
the vehicle location estimation method comprising:
acquiring an azimuth of the travel path direction of the host vehicle;
estimating a curvature radius of a road on which the host vehicle is traveling;
receiving the location of the other vehicle;
receiving an azimuth of the direction of travel of the other vehicle;
arranging the other vehicle on a coordinate system, an origin of which is a position of the host vehicle, and an axis of which is the travel path direction in which the host vehicle is travelling;
determining a lane on which the other vehicle is travelling, a lane on which the host vehicle is travelling, the direction of travel in which the other vehicle is travelling, and the travel path direction in which the hos

Assignees

• Shida Mitsuhisa
• Doi Tomoyuki
• Toyota Motor Co Ltd

Inventors

• Shida Mitsuhisa
• Doi Tomoyuki

Classifications

• G08G1/167 Primary

  Driving aids for lane monitoring, lane changing, e.g. blind spot detection · CPC title

• H04L67/12

  specially adapted for proprietary or special-purpose networking environments, e.g. medical networks, sensor networks, networks in vehicles or remote metering networks · CPC title

• G01C21/26

  specially adapted for navigation in a road network · CPC title

• G08G1/161 Primary

  Decentralised systems, e.g. inter-vehicle communication · CPC title