US5040116A — Visual navigation and obstacle avoidance structur…

Claim 1

Independent Claim 169 words

A method of generating navigation related information for a mobile robot, comprising the steps of: projecting at least one structured, substantially planar radiation beam into an environment in front of and including a desired path of the robot, said radiation beam forming a linear pattern upon a surface disposed within the environment; generating a two-dimensional pixel image of the environment, said image including at least an image of said linear pattern which reflects from a surface, if any, within the environment; locating said image of said linear pattern within the two-dimensional pixel image of the environment of said robot; inferring from the located position of the linear pattern, within said image of the environment, a range and a bearing of the surface relative to the robot; generating a geometric map representation that includes a location of the surface, relative to a current location of said robot; and processing said geometric map representation to generate robot motion control signals to accomplish a forward motion of said robot through the environment.

Claim 2

Independent Claim 169 words

A method of generating navigation related information for a mobile robot, comprising the steps of: projecting at least one structured, substantially planar radiation beam into an environment in front of and including a desired path of the robot, said radiation beam forming a linear pattern upon a surface disposed within the environment; generating a two-dimensional pixel image of the environment, said image including at least an image of said linear pattern which reflects from a surface, if any, within the environment; locating said image of said linear pattern within the two-dimensional pixel image of the environment of said robot; inferring from the located position of the linear pattern, within said image of the environment, a range and a bearing of the surface relative to the robot; generating a geometric map representation that includes a location of the surface, relative to a current location of said robot; and processing said geometric map representation to generate robot motion control signals to accomplish a forward motion of said robot through the environment.

Claim 3

Dependent Claim 52 words

A method as defined in claim 1 wherein the step of generating a two-dimensional pixel image generates an image comprised of a two dimensional array of pixels, each of said pixels having an associated value which is a function of an amount of reflected radiation received from an associated portion of environment.

Claim 4

Dependent Claim 42 words

A method as defined in claim 2 wherein the step of locating includes a step of determining a location, within said array of pixels, of one or more pixels which have a value equal to or greater than a predetermined threshold value.

Claim 5

Dependent Claim 56 words

A method as defined in claim 3 wherein the step of inferring includes a step of accessing an entry within a data structure having a plurality of range and bearing entries, each of said entries corresponding to one of said pixels, a location of said entry being accessed being a function of said determined pixel location.

Claim 6

Dependent Claim 28 words

A method as defined in claim 3 wherein the step of inferring includes a step of converting a value of each of said pixels to a binary value.

Claim 7

Dependent Claim 80 words

A method as defined in claim 3 wherein the step of locating includes a first step of searching said image of the environment with a resolution of n pixels to locate a pixel or pixels having a a value equal to or greater than said predetermined threshold value, and further includes a second step of searching said image of the environment with a resolution of m pixels, after said pixel or pixels are located, wherein n is greater than m.

Claim 8

Dependent Claim 61 words

A method as defined in claim 1 wherein the step of generating a geometric map representation includes the steps of: representing an underlying surface over which the robot moves as a two dimensional grip comprised of grid cells; and designating those grid cells which correspond to a range and a bearing, relative to said robot, to said linear pattern reflecting surface.

Claim 9

Dependent Claim 36 words

A method as defined in claim 7 and further comprising the step of: assigning a confidence factor to designated grid cells based upon a plurality of consistently inferred ranges and bearings corresponding to said designated cells.

Claim 10

Dependent Claim 26 words

A method as defined in claim 8 and further comprising a step of: determining a radius which encloses one or more of said designated grid cells.

Claim 11

Dependent Claim 179 words

Apparatus for generating navigation related information for a mobile robot, comprising in combination: means for projecting at least one structured, substantially planar radiation beam into an environment in front of and including a desired path of said robot, said radiation beam forming a linear pattern upon a surface disposed within the environment; means for generating a two-dimensional pixel image of the environment, said image including at least an image of said linear pattern which reflects from a surface, if any, within said environment; means for locating said image of said linear pattern within said two-dimensional pixel image of the environment; means for inferring, from the located position within said image of said linear pattern, a range and a bearing relative to said robot, of said surface reflecting said linear pattern; means for generating a geometric map representation of said robot's environment, said geometric map representation including the inferred surface position of said linear pattern; and means for processing said geometric map representation to generate robot motion control signals to accomplish a forward motion of said robot through the environment.

Claim 12

Dependent Claim 179 words

Apparatus for generating navigation related information for a mobile robot, comprising in combination: means for projecting at least one structured, substantially planar radiation beam into an environment in front of and including a desired path of said robot, said radiation beam forming a linear pattern upon a surface disposed within the environment; means for generating a two-dimensional pixel image of the environment, said image including at least an image of said linear pattern which reflects from a surface, if any, within said environment; means for locating said image of said linear pattern within said two-dimensional pixel image of the environment; means for inferring, from the located position within said image of said linear pattern, a range and a bearing relative to said robot, of said surface reflecting said linear pattern; means for generating a geometric map representation of said robot's environment, said geometric map representation including the inferred surface position of said linear pattern; and means for processing said geometric map representation to generate robot motion control signals to accomplish a forward motion of said robot through the environment.

Claim 13

Dependent Claim 48 words

Apparatus as set forth in claim 10 wherein said image generating means generates an image comprised of a two dimensional array of pixels, each of said pixels having an associated value which is a function of an amount of reflected radiation within an associated portion of said image.

Claim 14

Dependent Claim 39 words

Apparatus as set forth in claim 11 wherein said location means includes means for determining a location within said array of pixels of one or more pixels having a value equal to or greater than a predetermined threshold value.

Claim 15

Dependent Claim 54 words

Apparatus as set forth in claim 11 wherein said inferring means includes means for accessing an entry within a data storage means having a plurality of range and bearing entries, each of said entries corresponding to one of said pixels, a location of an accessed entry being a function of a determined pixel location.

Claim 16

Dependent Claim 27 words

Apparatus as set forth in claim 11 wherein said means for inferring includes means for converting a value of each of said pixels to a binary value.

Claim 17

Dependent Claim 67 words

Apparatus as set forth in claim 11 wherein said locating means includes means for searching said image of the environment with a resolution of n pixels to locate a pixel or pixels having a value equal to or greater than said predetermined threshold value, and further includes means for searching said image of the environment with a resolution of m pixels, wherein n is greater than m.

Claim 18

Dependent Claim 102 words

Apparatus as set forth in claim 10 wherein said means for generating a geometric map representation comprises: means for representing an underlying surface over which the robot moves as a two dimensional grip comprised of grid cells; means for designating those grid cells which correspond to a range and a bearing, relative to said robot, of said linear pattern reflecting surface; means for assigning a confidence factor to designated grid cells based upon a plurality of consistently inferred ranges and bearings corresponding to said designated cells; and means for determining a radius that encloses one or more of said designated grid cells.

Claim 19

Dependent Claim 169 words

Apparatus for generating navigation information for a vehicle, comprising: means for projecting at least one structured, substantially planar radiation beam into an environment in front of and including a desired path of a vehicle; means for repetitively generating two-dimensional pixel images of the environment as the vehicle moves through the environment, each of said pixel images including an image of a reflection or reflections of said structured radiation beam that reflects from an object or objects within the environment; means for detecting a location, within each of the two-dimensional pixel images, of said image of the reflection or reflections; means for determining from a change in the located position of the image of the reflection or reflections, over a plurality of two-dimensional pixel images, a position, relative to the vehicle, of an object or objects disposed within the environment; and means, responsive to the determined position of the object or objects, for generating vehicle motion control signals so as to steer the vehicle along a path through the environment.

Claim 20

Dependent Claim 169 words

Apparatus for generating navigation information for a vehicle, comprising: means for projecting at least one structured, substantially planar radiation beam into an environment in front of and including a desired path of a vehicle; means for repetitively generating two-dimensional pixel images of the environment as the vehicle moves through the environment, each of said pixel images including an image of a reflection or reflections of said structured radiation beam that reflects from an object or objects within the environment; means for detecting a location, within each of the two-dimensional pixel images, of said image of the reflection or reflections; means for determining from a change in the located position of the image of the reflection or reflections, over a plurality of two-dimensional pixel images, a position, relative to the vehicle, of an object or objects disposed within the environment; and means, responsive to the determined position of the object or objects, for generating vehicle motion control signals so as to steer the vehicle along a path through the environment.

Claim 21

Dependent Claim 36 words

Apparatus as set forth in claim 17 wherein said determining means includes means for determining, for each of the two-dimensional pixel images, a range and a bearing, relative to the vehicle, of the object or objects.

Claim 22

Dependent Claim 31 words

Apparatus as set forth in claim 18 wherein said determining means further includes means, responsive to the determined ranges and bearings, for generating a geometric map representation of the vehicle's environment.

Claim 23

Dependent Claim 62 words

Apparatus as set forth in claim 17 wherein each of said two-dimensional pixel images is comprised of a plurality of pixels and wherein said detecting means includes means for searching a first portion of said two-dimensional pixel image with a first pixel resolution, and further includes means for searching a second portion of said two-dimensional pixel image with a second pixel resolution.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1994-08-12	1995-02-11	1995-08-13	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1998-08-12	1999-02-11	1999-08-13	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2002-08-12	2003-02-11	2003-08-13	$7700.00	Window Closed / Lapsed

Visual navigation and obstacle avoidance structured light system

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