Position and heading detecting device for self controlled vehicle

• US 5,220,508 A
• Filed: 12/27/1990
• Issued: 06/15/1993
• Est. Priority Date: 12/28/1989
• Status: Expired due to Fees

• Current Assignee: Kabushiki Kaisha Toyota Chuo Kenkyusho (Toyota Motor Corporation)
• Original Assignee: Kabushiki Kaisha Toyota Chuo Kenkyusho (Toyota Motor Corporation)
• Inventors: Yamamoto, Yuzo, Tange, Koichi, Sugimoto, Gunji, Ninomiya, Yoshiki
• Primary Examiner(s): Chin, Gary
• Application Number:
  US07/634,613
• Time in Patent Office: 901 Days
• Field of Search: 364/443, 364/449, 364/424.02, 318/587, 358/103, 180/167, 180/168, 180/169
• US Class Current: 701/207
• CPC Class Codes: G01S 3/7864 T.V. type tracking systems
• CPC Class Codes: G05D 1/0246 using a video camera in combination with image processing means
• CPC Class Codes: G05D 1/0272 comprising means for registering the travel distance, e.g. revolutions of wheels measuring distance traversed on the ground by vehicles, e.g. using odometers G01C22/00

Abstract

An outer environment of the vehicle is inputted as an image. Image processing is performed to the input image, and many edge segments are extracted. The edge segments which are colinear are clustered in order to perform a matching operation. Matching is performed in a respective set of plural longer edge segments representing plural clusters in correspondence with a set of plural guide signs as standards of guide of the vehicle mapped on the image input surface, and a set of longer edge segments being most matched each other is extracted. From position and headings of the extracted longer edge segments on the image input surface, the position and heading in the outer environment are calculated. The position and heading of the vehicle are detected from these values. The position and heading of the vehicle obtained in the above-mentioned image processing and the position and heading of the vehicle measured by other techniques and are evaluated synthetically. When the guide signs are mapped on the image input surface, the forecast values of position and heading of the vehicle at the image input time are used. In this manner, the detecting accuracy of the position and heading of the vehicle is improved.

Claims

1. A position and heading direction detecting device for a self-controlled vehicle, comprising:

image input means for inputting an image of an outer environment of the self-controlled vehicle;

edge segment extracting means for receiving said image inputted by said image input means and for extracting and outputting edge segments of said image;

guide sign searching means comprising

clustering means for entering said edge segments extracted by said edge segment extracting means, for evaluating an alignment property of said edge segments based on respective mutual angle and distance relationships between any two of said edge segments, for assembling said edge segments evaluated to be on the same line into longer edge segments, and for outputting each of the assembled longer edge segments, and

selecting means for selecting one of said longer edge segments, corresponding to at least one guide sign, from among said assembled longer edge segments outputted from said clustering means, wherein said selected longer edge segment is selected based on at least one of a reference position and a reference angle of said at least one guide sign, said reference position and reference angle corresponding to a location of the outer environment; and

vehicle position/heading direction calculating means for transforming said longer edge segment selected by said selecting means into coordinates corresponding to known locations of the outer environment, for calculating a position of the vehicle relative to said selected longer edge segment in the transformed coordinates to decide a position and heading direction of the vehicle.

2. A detecting device as set forth in claim 1, further comprising:

guide sign storage means for setting a respective guide sign for every location in the outer environment of the vehicle and for storing at least position information of said guide sign,

wherein said guide sign searching means selects said longer edge segment corresponding to said respective guide sign based on said position information of said guide sign stored in said guide sign storage means.

3. A detecting device as set forth in claim 1, further comprising:

position/heading direction measuring means for measuring a current position and heading direction of the vehicle; and

position/heading direction integrating means for calculating the position and heading direction of the vehicle based on said position and heading direction of the vehicle calculated by said vehicle position/heading direction calculating means and said position and heading direction measured by said position/heading direction measuring means.

4. A detecting device as set forth in claim 1, further comprising:

guide sign storage means for storing a set of plural guide signs corresponding to each of plural locations in the outer environment of the vehicle; and

said guide sign searching means having matching decision means for deciding respective degrees of matching in a respective set of plural positions and heading directions of the vehicle, based on a respective set of plural longer edge segments arbitrarily selected in accordance with said set of plural guide signs corresponding to each of said plural locations in the outer environment of the vehicle,

wherein said selecting means determines said selected longer edge segment corresponding to a respective guide sign among said longer edge segments based on said degree of matching decided by said matching decision means.

5. A detecting device as set forth in claim 1, further comprising:

guide sign storage means for storing a set of plural guide signs corresponding to each of a plurality of locations in the outer environment of the vehicle; and

said guide sign searching means having matching decision means for deciding respective degrees of matching in a respective set of plural positions and heading directions of the vehicle decided by said vehicle position/heading direction calculating means based on a respective set of plural longer edge segments arbitrarily selected in accordance with said set of plural guide signs corresponding to said plurality of locations in the outer environment of the vehicle,

wherein said selecting means determines said respective selected longer edge segment corresponding to said respective guide sign among said longer edge segments based on said degree of matching and a length and distance corresponding to said guide sign for said respective longer edge segment, said length being outputted from said clustering means, said distance being calculated by said guide sign searching means.

6. A detecting device as set forth in claim 1, further comprising:

guide sign storage means for storing plural guide signs corresponding to each of a plurality of locations in the outer environment of the vehicle; and

camera calibration means for calibrating a tilt angle of said image input means for use in calculating said position and heading direction of said vehicle by said vehicle position/heading direction calculating means based on said plural selected longer edge segments to collate said plural guide signs respectively selected by said selecting means.

7. A detecting device as set forth in claim 1, further comprising:

position/heading direction forecast means for forecasting the position and heading direction of the vehicle at a time when said image is input by said image input means,

wherein said guide sign searching means limits a region to select said longer edge segment corresponding to said at least one guide sign based on the position and heading direction of the vehicle forecasted by said position/heading direction forecasting means at the time when said image is input by said image input means.

8. A detecting device as set forth in claim 2, further comprising:

position/heading direction forecast means for forecasting the position and heading direction of the vehicle at a time when said image is input by said image input means,

wherein said guide sign searching means maps said guide sign stored in said guide sign storage means onto the image coordinates based on the position and heading direction of the vehicle forecasted by said position/heading direction forecast means at the time when said image is input by said image input means, and selects said longer edge segment corresponding to said guide sign based on said mapped guide sign.

9. A detecting device as set forth in claim 1, further comprising:

position/heading direction forecast means for forecasting the position and heading direction of the vehicle at a time when said image is input by said image input means,

wherein said vehicle position/heading direction calculating means determines corrected values for the position and heading direction of the vehicle, at the time when said image is input by said image input means, based on the position and heading direction of the vehicle determined from said selected longer edge segment and the position and heading direction of the vehicle forecasted by said position/heading direction forecast means at the time when said image is input by said image input means, and calculates the current position and heading direction of the vehicle based on the corrected values.

10. A detecting device as set forth in claim 3, further comprising:

position/heading direction forecast means for forecasting the position and heading direction of the vehicle, at a time when said image is input by said image input means, in accordance with output from said position/heading direction measuring means,

wherein said position/heading direction integrating means calculates a calibrated position and heading direction of the vehicle, at the time when said image is input by said image input means, said calibrated position and heading direction being determined by said selected longer edge segment and the position and heading direction of the vehicle forecasted by said position/heading direction forecast means at the time when said image is input by said image input means, and calculates a displacement between said current position and heading direction of the vehicle obtained by said position/heading direction measuring means and the position and heading direction of the vehicle forecasted by said position/heading direction forecast means at the time when said image is input by said image input means, and determines a new current position and new heading direction of the vehicle based on said calibrated position, said heading direction and said displacement.

11. A detecting device as set forth in claim 1, further comprising:

position/heading direction measuring means for measuring a current position and heading direction of the vehicle;

position/heading direction forecast means for forecasting the position and heading direction of the vehicle, at a time when said image is input by said image input means, in accordance with output from said position/heading direction measuring means; and

position/heading direction integrating means for calculating a calibrated position and heading direction of the vehicle at the time when said image is input by said image input means based on the position and heading direction of the vehicle determined from said selected longer edge segment by said vehicle position and heading direction calculating means, and also based on the position and heading direction of the vehicle forecasted by said position/heading direction forecast means at the time when said image in input by said image input means.

12. A detecting device as set forth in claim 3, wherein said position/heading direction measuring means measures the position and heading direction by measuring the revolutions of a wheel of the vehicle.

13. A detecting device as set forth in claim 7, wherein said position/heading direction forecast means measures the revolutions of a wheel of the vehicle and forecasts the position and heading direction of the vehicle at the time when said image is input by said image input means.

14. A detecting device as set forth in claim 7, wherein said position/heading direction forecast means forecasts the position and heading direction of the vehicle, at the time when said image is input by said image input means, based on the position and heading direction of the vehicle calculated by said vehicle position/heading direction calculating means.