Three-dimensional optical volume measurement for objects to be categorized

• US 6,369,401 B1
• Filed: 09/10/1999
• Issued: 04/09/2002
• Est. Priority Date: 09/10/1999
• Status: Expired due to Fees

• Current Assignee: Agri-Tech, Inc.
• Original Assignee: Agri-Tech, Inc.
• Inventors: Lee, Dah-Jye
• Primary Examiner(s): Allen, Stephone B.
• Application Number:
  US09/392,505
• Time in Patent Office: 942 Days
• Field of Search: 250/559.2, 250/559.21, 250/559.24, 250/559.27, 356/379, 356/380, 356/381, 356/384, 356/387, 356/391, 356/398, 356/623, 356/627, 356/628
• US Class Current: 250/559.21
• CPC Class Codes: G01B 11/00 Measuring arrangements characterised by the use of optical techniques
• CPC Class Codes: G01B 11/0608 Height gauges

Abstract

A three-dimensional measurement system and method for objects, such as oysters, projects one or more laser lines onto a surface on which the object is currently located. The laser lines are picked up as parallel lines by a camera where no object is located on the surface. When an object is located on the surface, the camera obtains an image that includes lines displaced from the parallel lines as a result of the lines impinging on portions of the object that have a particular height associated therewith. The displacement data allows a processor to determine the height of the object at various positions of the object can be obtained. Volume can be obtained using a binary image of the object to calculate area from the height data. The object can then be classified according to its volume.

Claims

1. A method of measuring a height of a location on an object, comprising:

projecting at least one line of radiation onto the object;

detecting at least one line of radiation reflected from the object; and

comparing the at least one line of reflected radiation with radiation reflected from a reference surface to determine the height of the object at a location corresponding to where the at least one line of radiation impinges on the object,

wherein the at least one line of radiation is projected in a direction along a first angle with respect to the object, and wherein the at least one line of reflected radiation is detected along a direction corresponding to a second angle different from the first angle.

2. An apparatus for measuring a height of a location on an object, comprising:

an illumination source configured to output at least one line of radiation onto the object;

a detector configured to detect at least one line of radiation reflected from the object; and

a processing unit configured to process information corresponding to the at least one line of reflected radiation with information corresponding to radiation reflected from a reference surface to determine the height of the object at a location corresponding to where the at least one line of radiation impinges on the object,

wherein the at least one line of radiation is projected in a direction along a first angle with respect to the object, and wherein the at least one line of reflected radiation is detected along a direction corresponding to a second angle with respect to object.

3. A method of measuring a height of a location on an object, comprising:

projecting at least one line of radiation from a radiation source onto the object;

detecting at least one line of radiation reflected from the object; and

comparing the at least one line of reflected radiation with radiation reflected from a reference surface to determine the height of the object at a location corresponding to where the at least one line of radiation impinges on the object,

wherein the at least one line of radiation is projected in a direction along a first angle with respect to the object, and wherein the at least one line of reflected radiation is detected along a direction corresponding to a second angle with respect to object.

4. An apparatus for measuring a volume of an object, comprising:

a laser light source configured to output a plurality of laser lines onto a surface area on which the object is currently located, the laser lines forming a plurality of parallel lines on the surface area where no object is located thereon;

a camera having a plurality of pixel elements that receive light from a plurality of surface locations, respectively, the camera configured to receive light reflected off the object due to the plurality of laser lines impinging on the object; and

a processing unit configured to obtain a binary image of the object based on a light intensity received at each of the plurality of pixels of the camera, the binary image being used to determine a width and a length of the object;

the processing unit configured to determine a distance that each of the laser lines is displaced relative to a reference location corresponding to a location that said each laser line would be received if no object was currently located in the surface area,

the processing unit configured to determine a height of the object based on the determined distances, and

the processing unit configured to determine a volume of the object based on the determined height, width and length of the object,

wherein the laser light source is positioned at a first angle with respect to the surface area, and wherein the camera is positioned at a second angle with respect to the surface area that is different from the first area.