Tracking vision sensor

• US 4,822,163 A
• Filed: 06/26/1986
• Issued: 04/18/1989
• Est. Priority Date: 06/26/1986
• Status: Expired due to Term

• Current Assignee: Rudolph Technologies Incorporated (Onto Innovation Inc.)
• Original Assignee: Robotic Vision Systems, Inc. (Omron Corporation)
• Inventors: Schmidt, Richard
• Primary Examiner(s): Buczinski, Stephen C.
• Assistant Examiner(s): Koltak, Melissa L.
• Application Number:
  US06/879,203
• Time in Patent Office: 1,027 Days
• Field of Search: 356/1, 356/4, 356/5, 356/376, 356/152, 356/141
• US Class Current: 356/3.03
• CPC Class Codes: G01S 17/89 for mapping or imaging

Abstract

An arrangement in which three-dimensional surface measurements are obtained by projecting a non-planar light beam on a surface and interpreting the image by triangulation. The non-planar beam makes it possible to determine its angle of incidence with the surface in an unambiguous manner, and allows surrounding a manufacturing process to provide continuous data when guiding the process around corners. A non-planar reflecting surface or other arrangement is used to generate the non-planar light beam from a planar light source. A flying spot of light may also be used. After the non-planar beam has been generated, it is projected upon the surface to be measured and forms there an intersection of the beam with the surface. Light reflected from the intersection is imaged from an angle different than the projected beam, and coordinates are generated of the surface intersection points illuminated by the projected beam based on the known angle of projection, known angle of imaging, and distance between projection source and imaging site.

Claims

1. A method for carrying out non-coplanar 3-D measurements of surface points, comprising the steps of:

forming light from a light source into a plane of light;

reshaping said plane of light into a non-planar beam;

projecting from a projection source said non-planar beam upon a surface to be measured and forming an intersection of said beam with said surface;

imaging at an imaging site light reflected from said intersection from an angle different than said projected beam; and

generating coordinates of said surface intersection points illuminated by said projected beam based on a known angle of projection, known angle of imaging and distance between projection source and imaging site.

4. A method defined in claim 1, wherein said plane of light is effectively generated by a flying spot.

5. A method as defined in claim 1, wherein said plane of light is reshaped by a "V"-shaped reflecting surface.

6. A method as defined in claim 1, wherein said plane of light is reshaped by a cylindrical reflecting surface.

7. A method as defined in claim 1, wherein said plane of light derives from a point source and is reshaped into a "V"-shape by a flat reflecting surface.

8. A method as defined in claim 1, wherein said non-planar beam is effectively generated directly by a flying spot.

2. A method of guiding a manufacturing process continuously around corners, comprising the steps of:

measuring surface points at least partially surrounding the manufacturing process by forming light from a light source into a plane of light;

reshaping said plane of light into a non-planar beam;

projecting from a projection source said non-planar beam upon a surface to be measured and forming an intersection of said beam with said surface;

imaging at an imaging site light reflected from said intersection from an angle different than said projected beam;

generating coordinates of said surface intersection points illuminated by said projected beam based on a known angle of projection, known angle of imaging and distance between projection source and imaging site;

directing said process to proceed on the basis of said measured points; and

maintaining required orientation of said projected beam to follow contours of said surface.

3. A method of obtaining the angle of incidence of a light beam with a surface, comprising the steps of:

measuring points on a surface by forming light from a light source into a plane of light;

reshaping said plane of light into a non-planar beam;

projecting from a projection source said non-planar beam upon a surface to be measured and forming an intersection of said beam with said surface;

imaging at an imaging site light reflected from said intersection from an angle different than said projected beam;

generating coordinates of said surface intersection points illuminated by said projected beam based on a known angle of projection, known angle of imaging and distance between projection source and imaging site; and

computing the angle of incidence of said projected beam from said measured points.