EP0358628A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Visual navigation and obstacle avoidance structured light system
Assignee: Transitions Research Corp
•
Filing: 1989-09-06
•
Granted: —
•
Expires: 2009-09-06
Abstract
Abstract A vision system for a vehicle, such as a mobile robot (10) includes at least one radiation projector (14,16) which projects a structured beam of radiation into the robot's environment.The structured beam of radiation (14a, 16a) preferably has a substantially planar pattern of sufficient width to encompass the immediate forward path of the robot and also to encompass laterally disposed areas in order to permit turning adjustments. The vision system further includes an imaging (12) sensor such as a CCD imaging device having a two-dimensional field of view which encompasses the immediate forward path of the robot. An image sensor processor (18) includes an image memory (18A) coupled to a device (18D) which is operable for accessing the image memory. Image processing is accomplished in part by triangulating the stored image of the structured beam pattern to derive range and bearing, relative to the robot, of an object being illuminated. A navigation control system (20) of the robot inputs data from at least the vision system and infers therefrom data relating to the configuration of the environment which lies in front of the robot. The navigation control system generates control signals which drive propulsion and steering motors in order to navigate the robot through the perceived environment.
Inventors
- 👤 John Martin Evans, Jr.
- 👤 Carl Frederick Reinhold Weiman
- 👤 Steven Joseph King
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-24 09:27
CPC Classifications
G; G05; G05D; G05D1/00; G05D1/02; G05D1/021; G05D1/0231; G05D1/0246; G01; G01C; G01C21/00; G01C21/38; G01C21/3804; G01C21/3833; G01C21/3837; G01S; G01S17/00; G01S17/88; G01S17/93; G01S17/931; G05D1/0268; G05D1/0274
Claims Analysis
Total Claims: 37
Claim 1
Independent Claim
86 words
Object dectection apparatus carried by a vehicle which moves over a surface, comprising: means for transmitting at least one structured, substantially planar radiation beam in a direction of travel of the vehicle; means for detecting the planar radiation beam which is reflected from at least one surface disposed within a region through which the vehicle is to travel; and means for associating the detected radiation beam with at least a range and a bearing, relative to the vehicle, of the surface reflecting the planar radiation beam.
Claim 2
Dependent Claim
86 words
Object dectection apparatus carried by a vehicle which moves over a surface, comprising: means for transmitting at least one structured, substantially planar radiation beam in a direction of travel of the vehicle; means for detecting the planar radiation beam which is reflected from at least one surface disposed within a region through which the vehicle is to travel; and means for associating the detected radiation beam with at least a range and a bearing, relative to the vehicle, of the surface reflecting the planar radiation beam.
Claim 3
Dependent Claim
36 words
Object detection apparatus as defined in claim 1 and further comprising means, coupled to an output of said associating means, for determining vehicle navigation data as a function of the range and bearing to the surface.
Claim 4
Dependent Claim
19 words
Object detection apparatus as defined in claim 1 wherein said means for transmitting comprises a pulsed source of radiation.
Claim 5
Dependent Claim
29 words
Object detection apparatus as defined in claim 3 wherein said source of radiation has output wavelengths within a range of wavelength of approximately 700 nm to approximately 1000 nm.
Claim 6
Dependent Claim
56 words
Object detection apparatus as defined in claim 1 wherein said means for detecting comprises means for generating a two-dimensional field of view comprising a plurality of pixels, each of said pixels having an associated value which is a function of the amount of the reflected structured radiation whithin an associated portion of the field of view.
Claim 7
Dependent Claim
30 words
Object detection apparatus as defined in claim 4 wherein said means for detecting comprises a CCD imaging device which generates a two-dimensional field of view comprising a plurality of pixels.
Claim 8
Dependent Claim
30 words
Object detection apparatus as defined in claim 5 wherein said means for associating comprises means for generating a range and a bearing for each pixel within the field of view.
Claim 9
Dependent Claim
32 words
Object detection apparatus as defined in claim 7 wherein said associating means further comprises means for storing data expressive of the range and bearing for each pixel within the field of view.
Claim 10
Independent Claim
148 words
A method of generating navigation related information for a mobile robot which moves upon a supporting surface, 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, the radiation beam forming a stripe-like pattern on a surface disposed within the environment; generating a two-dimensional image of the environment, the image including at least the stripe-like pattern which reflects from a surface, if any, within the environment; locating the image of a stripe-like pattern in the image; inferring from the position within the image of the stripe-like pattern a range and a bearing of the surface relative to the robot; generating a geometric map representation of the inferred surface position; and processing the map information to generate robot motion control signals which result in avoidance of obastacles or navigation to reference landmarks.
Claim 11
Independent Claim
148 words
A method of generating navigation related information for a mobile robot which moves upon a supporting surface, 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, the radiation beam forming a stripe-like pattern on a surface disposed within the environment; generating a two-dimensional image of the environment, the image including at least the stripe-like pattern which reflects from a surface, if any, within the environment; locating the image of a stripe-like pattern in the image; inferring from the position within the image of the stripe-like pattern a range and a bearing of the surface relative to the robot; generating a geometric map representation of the inferred surface position; and processing the map information to generate robot motion control signals which result in avoidance of obastacles or navigation to reference landmarks.
Claim 12
Dependent Claim
48 words
A method as defined in claim 9 wherein the step of generating generates an image comprised of a two-dimensional array of pixels, each of the pixels having an associated value which is a function of the amount of the reflected radiation within an associated portion of the image.
Claim 13
Dependent Claim
42 words
A method as defined in claim 10 wherein the step of locating includes a step of determining the location within the array of pixels of one or more pixels which have a value equal to or greater than a predetermined threshold value.
Claim 14
Dependent Claim
56 words
A method as defined in claim 11 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 the entries corresponding to one of the pixels, the location of the entry being accessed being a function of the determined pixel location.
Claim 15
Dependent Claim
28 words
A method as defined in claim 11 wherein the step of inferring includes a step of converting a value of each of the pixels to a binary value.
Claim 16
Dependent Claim
73 words
A method as defined in claim 11 wherein the step of location is accomplished by first searching the image with a resolution of n pixels to first locate a pixel or pixels having a value equal to or greater than the predetermined threshold value and is further accomplished by searching the image with a resolu tion of m pixels after the pixel or pixels are located, and wherein n is greater than m.
Claim 17
Dependent Claim
54 words
A method as defined in claim 9 wherein the step of generating a geometric map includes the steps of: representing the supporting surface as a two-dimensional grid comprised of grid cells; and designating those grid cells which corresponds to a range and a bearing, relative to the robot, of the stripe-like pattern reflecting surface.
Claim 18
Dependent Claim
36 words
A method as defined in claim 15 and further comprising the step of: assigning a confidence factor to designated grid cells based upon a persistence of inferred ranges and bearings which correspond to the designated cells.
Claim 19
Dependent Claim
24 words
A method as defined in claim 16 and further comprising a step of: determing a radius which encloses one or more designated grid cells.
Claim 20
Dependent Claim
105 words
A vision system coupled to a mobile robot, comprising: means for transmitting at least one structured, substantially planar radiation beam in a direction of travel of the robot; means for detecting the planar radiation beam which is reflected from at least one surface disposed within a region through which the robot is to travel; means for associating the detected radiation beam with a range and a bearing, relative to the robot, of the surface reflecting the planar radiation beam; and means, coupled to an output of said associating means, for determining robot navigation data as a function of the range and bearing to the surface.
Claim 21
Dependent Claim
105 words
A vision system coupled to a mobile robot, comprising: means for transmitting at least one structured, substantially planar radiation beam in a direction of travel of the robot; means for detecting the planar radiation beam which is reflected from at least one surface disposed within a region through which the robot is to travel; means for associating the detected radiation beam with a range and a bearing, relative to the robot, of the surface reflecting the planar radiation beam; and means, coupled to an output of said associating means, for determining robot navigation data as a function of the range and bearing to the surface.
Claim 22
Dependent Claim
16 words
A vision system as defined in claim 18 wherein said means for transmitting comprises a flashlamp.
Claim 23
Dependent Claim
20 words
A vision system as defined in claim 18 wherein said means for transmitting comprises one or more light emitting diodes.
Claim 24
Dependent Claim
19 words
A vision system as defined in claim 18 wherein said means for transmitting comprises one or more incandescent lamps.
Claim 25
Dependent Claim
19 words
A vision system as defined in claim 18 wherein said means for transmitting comprises one or more laser means.
Claim 26
Dependent Claim
25 words
A vision system as defined in claim 18 wherein the beam is transmitted substantially parallel to a substantially planar surface over which the robot moves.
Claim 27
Dependent Claim
26 words
A vision system as defined in claim 18 wherein the beam is transmitted obliquely downward relative to a substantially planar surface over which the robot moves.
Claim 28
Dependent Claim
26 words
A vision system as defined in claim 18 wherein the beam is transmitted substantially perpendicularly relative to a substantially planar surface over which the robot moves.
Claim 29
Dependent Claim
18 words
A vision system as defined in claim 18 wherein said means for detecting comprises a CCD imaging means.
Claim 30
Dependent Claim
18 words
A vision system as defined in claim 18 wherein said means for detecting comprises a vidicon imaging means.
Claim 31
Dependent Claim
125 words
A vision system as defiend in claim 19 wherein said flashlamp comprises a flashlamp having an elongated shape and wherein said means for transmitting further comprises in combination: a substantially semicircular cylindrical reflector means disposed substantially parallel to said flashlamp; first cylindrical lens means having a focal length and being disposed substantially parallel to said flashlamp for focussing radiation emanating from said flashlamp and also from said reflector means, and second cylindrical means having a focal length and being disposed substantially parallel to said first cylindrical lens means at a distance which is greater than the focal length of said first cylindrical lens means, said second cylindrical lens means collimating the radiation from said first cylindrical lens means for generating said substantially planar radiation beam.
Claim 32
Dependent Claim
15 words
A vision system as defined in claim 28 wherein said flashlamp comprises a xenon flashlamp.
Claim 33
Dependent Claim
26 words
A vision system as defined in claim 28 wherein said first and said second cylindrical lens means each have a focal length of approximately 0.5 inches.
Claim 34
Dependent Claim
19 words
A vision system as defined in claim 28 wherein each of said cylindrical lens means comprise a Fresnel lens.
Claim 35
Dependent Claim
33 words
A vision system as defined in claim 28 wherein said cylindrical reflector means has a focal length and wherein said flashlamp is disposed at approximately the focal length of said cylindrical reflector means.
Claim 36
Dependent Claim
41 words
A vision system as defined in claim 28 and further comprising an optical filter means disposed to receive said collimated radiation, said optical filter means passing radiation therethrough within a range of wavelengths of approximately 700 nm to approximately 1000 nm.
Claim 37
Dependent Claim
70 words
A vision system as defined in claim 19 wherein said flashlamp comprises a flashlamp having an elongated shape and wherein said means for transmitting further comprises in combination: a substantially semicircular cylindrical reflector means disposed substantially parallel to said flashlamp; and at least one slit-like aperture disposed substantially parallel to said flashlamp for forming radiation emanating from said flashlamp and said reflector means into a substantially planar beam of radiation.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.