Visual sensor system

• US 4,985,847 A
• Filed: 01/13/1988
• Issued: 01/15/1991
• Est. Priority Date: 01/14/1987
• Status: Expired due to Term

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Shioya, Makoto, Adachi, Masao
• Primary Examiner(s): Lall, Parshotam S.
• Assistant Examiner(s): TRANS, VINCENT N
• Application Number:
  US07/143,482
• Time in Patent Office: 1,098 Days
• Field of Search: 250/560, 250/561, 250/562, 250/563, 250/572, 250/200, 250/201, 250/202, 356/237, 358/106, 358/107, 358/108, 358/103, 364/424.01, 364/424.05, 364/516, 364/556, 364/560, 364/561, 364/562
• US Class Current: 701/36
• CPC Class Codes: B60G 17/019 characterised by the type of sensor or the arrangement thereof B60G17/01941 takes precedence
• CPC Class Codes: G01C 3/10 using a parallactic triangle with variable angles and a base of fixed length in the observation station, e.g. in the instrument

Abstract

A visual sensor system includes a moving object movable along a two-dimensional plane, and a one-dimensional array of photosensitive means fixedly mounted on the moving object. The photosensitive means are arranged in such a manner that the array is located within a first plane substantially perpendicular to a central axis of a line of sight and forms, within the second plane, a given angle with a line intersecting a second plane containing the central axis of the line of sight and substantially perpendicular to the two-dimensional plane.

Claims

1. An image sensor system for a vehicle, comprising:

a one-dimensional array of photosensitive means mounted on said vehicle, said array of photosensitive means being arranged within an image plane and said array forming, within said image plane, a predetermined angle with respect to a line forming the intersection between said vehicle'"'"'s plane of motion and said image plane, such that edge features of images projected onto said image plane which are parallel to said intersection line and which are spaced apart in a direction perpendicular to said intersection line will have their respective points of intersection with said array spaced apart in the direction of said array angle, and image edge features projected onto said image plane which are perpendicular to said intersection line and which are spaced apart in a direction parallel with said intersection line will have their respective points of intersection with said array spaced apart in the direction of said array angle; and

a processing means which, based on outputs from said photosensitive means, detects image edges within said image plane which are parallel or perpendicular to said intersection line.

2. A system according to claim 1, wherein said predetermined angle is about 30 to 60 degrees.

3. A visual sensor system for detecting surface conditions on a path forward of a vehicle movable along a two-dimensional plane of movement, said system comprising:

means for detecting quantities convertible to a height above said plane of movement of the gravitational center of said vehicle and a pitch angle between a second plane, said second plane being fixed with respect to said vehicle and substantially perpendicular to a normal direction of motion of said vehicle, and said plane of movement;

a one dimensional array of photosensitive sensor means mounted on said vehicle, for detecting diffuse light reflected from said forward path;

means for extracting a feature of received information from said photosensitive means;

means for computing said height of gravitational center and said pitch angle ( ) from information detected by said detecting means; and

means for computing a distance (L) from said photosensitive sensor means to a point on said two-dimensional plane based on said feature extracted by said feature extracting means, said height of gravitational center and said pitch angle; and

means to determine a surface condition of said two-dimensional plane based on said computed distance and extracted feature.

4. A system according to claim 3, wherein said feature extracting means determines whether both sides of said extracted feature point have a predetermined combination of colors as a basis of determining a class of said surface condition.

5. A visual sensor system comprising:

a moving object movable along a two-dimensional plane;

a one-dimensional array of photosensitive means fixedly mounted on said moving object in such a manner that said photosensitive means are located within a first plane substantially perpendicular to a central axis of a line of sight and form, within said first plane, a predetermined angle with a line intersecting a second plane containing the central axis of said line of sight and substantially perpendicular to said two-dimensional plane;

means for detecting quantities convertible to a height of gravitational center and tilt angle (α

) about gravitational center of said moving object;

means for extracting a feature of received information of said photosensitive means forming a visual sensor;

means for computing a height of gravitational center and tilt angle (α

) about gravitational center of said moving object from information detected by said detecting means;

means for computing a distance (L) to said feature point on said two-dimensional plane from said feature extracted by said extracting means, said height of gravitational center and said tilt angle (α

) about gravitational center to determine a surface condition; and

means responsive to an output from said means for detecting a distance (L) to said feature point to control a suspension of said moving object.

6. A system according to claim 5, wherein said predetermined angle is about 30 to 60 degrees.