EP0363339A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Mobile robot navigation employing ceiling light fixtures
Assignee: Transitions Research Corp
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Filing: 1989-10-03
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Granted: —
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Expires: 2009-10-03
Abstract
Abstract Apparatus and method which provides for the determination of a vehicle's orientation and position in an environment, such as a hallway, from an image of ceiling lights. A mobile robot 10 includes a camera 12 that is pitched up obliquely at an intermediate angle between a horizon and a zenith. The camera views a ceiling having one or more ceiling lights 16 which may be of rectangular shape and which are preferably aligned with an axis of the hallway. In that the lights present a pattern or alignment which is substantially parallel to or perpendicular to a long axis of the hallway the pattern is detected an processed to derive robot navigation information therefrom.
Inventors
- 👤 John Martin Evans, Jr.
- 👤 Carl Frederick Reinhold Weiman
- 👤 Steven Joseph King
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-25 07:25
CPC Classifications
G; G05; G05D; G05D1/00; G05D1/02; G05D1/021; G05D1/0231; G05D1/0246; G05D1/0253; G01; G01S; G01S5/00; G01S5/16; G01S5/163; G05D1/0268; G05D1/0272
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
83 words
Navigation apparatus for generating navigation related information for a vehicle, comprising: means for obtaining an image of a surface which overlies a vehicle or a projected path of the vehicle, the surface having one or more sources of illumination disposed thereon; means, coupled to said obtaining means, for detecting a location within the image of the one of more sources; and means, coupled to said detecting means, for generating, from the detected source location or locations, at least vehicle position and orientation information.
Claim 2
Dependent Claim
83 words
Navigation apparatus for generating navigation related information for a vehicle, comprising: means for obtaining an image of a surface which overlies a vehicle or a projected path of the vehicle, the surface having one or more sources of illumination disposed thereon; means, coupled to said obtaining means, for detecting a location within the image of the one of more sources; and means, coupled to said detecting means, for generating, from the detected source location or locations, at least vehicle position and orientation information.
Claim 3
Dependent Claim
36 words
Navigation apparatus as set forth in claim 1 wherein said generating means comprises: means for determining an offset distance and an angular displacement of the vehicle relative to the location of the source within the image.
Claim 4
Dependent Claim
25 words
Navigation apparatus as set forth in claim 2 wherein said generating means further comprises means for determining a distance from the vehicle to the surface.
Claim 5
Dependent Claim
27 words
Navigation apparatus as set forth in claim 1 wherein said image obtaining means comprises means for forming a two-dimensional image comprised of a plurality of image pixels.
Claim 6
Dependent Claim
21 words
Navigation apparatus as set forth in claim 4 wherein said two-dimensional image forming means is comprised of a CCD camera means.
Claim 7
Dependent Claim
21 words
Navigation apparatus as set forth in claim 4 wherein said two-dimensional image forming means is comprised of a vidicon camera means.
Claim 8
Dependent Claim
34 words
Navigation apparatus as set forth in claim 4 wherein said detecting means comprises means, coupled to said two-dimensional image forming means, for identifying pixels which correspond to two substantially parallel edges of the source.
Claim 9
Dependent Claim
53 words
Navigation apparatus as set forth in claim 7 wherein said generating means comprises means, coupled to said pixel identifying means, for projecting a line from the pixels which correspond to the substantially parallel edges of the source, the intersection of each of the projected lines defining a vanishing point within the two-dimensional image.
Claim 10
Dependent Claim
62 words
Navigation apparatus as set forth in claim 8 wherein said pixel identifying means is further operable for identifying a pixel or pixels corresponding to a center of the source and wherein said projecting means is further operable for projecting a line from the pixel or pixels which define the center of the source such that the projected line intersects the vanishing point.
Claim 11
Dependent Claim
48 words
Navigation apparatus as set forth in claim 9 wherein said generating means further comprises: means for determining an offset distance and an angular displacement of the orientation relative at least to the line projected from the pixels corresponding to the center of the soruce to the vanishing point.
Claim 12
Dependent Claim
94 words
Navigation apparatus for generating navigation related information for a mobile robot, comprising. means for imaging at least a portion of a ceiling disposed over a forward path of a mobile robot; means for locating, within the imaged portion of the ceiling, a boundary of at least one ceiling light which is disposed within the imaged portion of the ceiling; means for generating a reference axis of robot motion relative to the located boundary of the ceiling light; and means for determining a position of the robot relative to the reference axis of robot motion.
Claim 13
Dependent Claim
94 words
Navigation apparatus for generating navigation related information for a mobile robot, comprising. means for imaging at least a portion of a ceiling disposed over a forward path of a mobile robot; means for locating, within the imaged portion of the ceiling, a boundary of at least one ceiling light which is disposed within the imaged portion of the ceiling; means for generating a reference axis of robot motion relative to the located boundary of the ceiling light; and means for determining a position of the robot relative to the reference axis of robot motion.
Claim 14
Dependent Claim
26 words
Navigation apparatus as set forth in claim 11 wherein said imaging means comprises means for forming a two-dimensional image comprised of a plurality of image pixels.
Claim 15
Dependent Claim
20 words
Navigation apparatus as set forth in claim 12 wherein said image forming means is comprised of a CCD camera means.
Claim 16
Dependent Claim
20 words
Navigation apparatus as set forth in claim 12 wherein said image forming means is comprised of a vidicon camera means.
Claim 17
Dependent Claim
23 words
Navigation apparatus as set forth in claim 11 and further comprising means for measuring a height of the ceiling relative to the robot.
Claim 18
Dependent Claim
32 words
Navigation apparatus as set forth in claim 11 and further comprising means, coupled to said determining means, for controlling a motion of the robot relative to the reference axis of robot motion.
Claim 19
Independent Claim
83 words
A method of providing navigation related information for a mobile robot, comprising the steps of: obtaining at least one image of a ceiling having one or more distinct visual features, the ceiling overlying at least the projected path of the robot; locating within the ceiling image the one or more distinct visual features; detecting a boundary of the distinct visual features; generating at least one reference line relative to the detected boundary; and determining a location of the robot relative the reference line.
Claim 20
Independent Claim
83 words
A method of providing navigation related information for a mobile robot, comprising the steps of: obtaining at least one image of a ceiling having one or more distinct visual features, the ceiling overlying at least the projected path of the robot; locating within the ceiling image the one or more distinct visual features; detecting a boundary of the distinct visual features; generating at least one reference line relative to the detected boundary; and determining a location of the robot relative the reference line.
Claim 21
Dependent Claim
44 words
The method of claim 17 wherein the step of obtaining an image includes a step of generating a plurality of image pixels each of which has a value which is a function of at least the brightness of a corresponding portion of the ceiling.
Claim 22
Dependent Claim
32 words
The method of claim 18 wherein the steps of locating and detecting are accomplished by identifying a pixel or pixels having a value which indicates the location of a ceiling light fixture.
Claim 23
Dependent Claim
35 words
The method of claim 17 wherein the step of generating at least one reference line includes a step of projecting perspective lines along detected boundaries such that the projected lines intersect at a vanishing point.
Claim 24
Dependent Claim
27 words
The method of claim 17 wherein the step of determining a position includes a step of determining an offset distance from the robot to the reference line.
Claim 25
Dependent Claim
29 words
The method of claim 21 wherein the step of determining a position includes a further step of determining an angular orientation of the robot relative to the reference line.
Claim 26
Independent Claim
163 words
A method a providing navigation information for a vehicle, comprising the steps of: imagining a surface which is disposed above at least the projected forward path of the vehicle, the surface having a height zO above the vehicle, the surface including one or more sources of illumination; detecting at least two opposing edges of one of the sources of illumination; detecting at least two opposing edges of a second one of the sources of illumination; determining a central point of each of the sources of illumination, a line passing through each of the center points defining an axis of alignment, the axis of alignment intersecting a vanishing point; projecting the axis of alignment unto the image to obtain a slope m; determining a pitch (Pch) component and a yaw (Yaw) component of vehicle orientation relative to the axis of alignment; and determining a lateral displacement xO of the vehicle from the axis of alignment in accordance with the equation: xO = -zO*cos(Yaw)/(m*cos(Pch)) -zO*sin(Pch*sin(Yaw)/cos(Pch).
Claim 27
Independent Claim
163 words
A method a providing navigation information for a vehicle, comprising the steps of: imagining a surface which is disposed above at least the projected forward path of the vehicle, the surface having a height zO above the vehicle, the surface including one or more sources of illumination; detecting at least two opposing edges of one of the sources of illumination; detecting at least two opposing edges of a second one of the sources of illumination; determining a central point of each of the sources of illumination, a line passing through each of the center points defining an axis of alignment, the axis of alignment intersecting a vanishing point; projecting the axis of alignment unto the image to obtain a slope m; determining a pitch (Pch) component and a yaw (Yaw) component of vehicle orientation relative to the axis of alignment; and determining a lateral displacement xO of the vehicle from the axis of alignment in accordance with the equation: xO = -zO*cos(Yaw)/(m*cos(Pch)) -zO*sin(Pch*sin(Yaw)/cos(Pch).
Claim 28
Dependent Claim
51 words
A method as set forth in claim 23 wherein the vanishing point is defined by coordinates uu and vv and wherein the pitch component is determined in accordance with the equation Pch = arctan (vv) and wherein the yaw component is determined in accordance with the equation Yaw = arctan (uu*cos(Pch)).
References Cited (Backward Citations)
No citation records indexed.
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