Three-dimensional shape-measuring system

• US 6,798,527 B2
• Filed: 04/24/2002
• Issued: 09/28/2004
• Est. Priority Date: 04/27/2001
• Status: Expired due to Fees

• Current Assignee: Minolta Corporation Limited (Konica Minolta Inc.)
• Original Assignee: Minolta Corporation Limited (Konica Minolta Inc.)
• Inventors: Ariizumi, Masahiro, Osaki, Shigeru, Matsunaga, Norio, Abe, Yoshihisa, Fukumoto, Tadashi
• Primary Examiner(s): Pham, Hoa Q.
• Application Number:
  US10/128,523
• Publication Number:
  US 20020171847A1
• Time in Patent Office: 888 Days
• Field of Search: 356/243--24, 356/601-624
• US Class Current: 356/602
• CPC Class Codes: G01B 11/245 using a plurality of fixed, simultaneously operating transducers G01B11/2408 - G01B11/2425, G01B11/255 take precedence
• CPC Class Codes: G01B 11/2518 Projection by scanning of the object

Abstract

An object of the present invention is to provide a method for accurately measuring a three-dimensional shape of a measuring subject independent of the surface shape of the measuring subject, and another object thereof is to shorten the time from the measurements of the measuring subject until three-dimensional shape data is obtained so as to carry out efficient measuring operations. In a three-dimensional measuring system 1 that measures a three-dimensional shape of a measuring subject, two three-dimensional measuring devices 10, 20 are placed. The three-dimensional measuring device 10 measures a measuring subject placed in a measuring space 3 by allowing a laser slit light L1 in a longitudinal direction to scan in a lateral direction. Moreover, the three-dimensional measuring device 20 measures the measuring subject placed in a measuring space 3 by allowing the laser slit light L1 in a lateral direction to scan in a longitudinal direction.

Claims

1. A three-dimensional shape-measuring system, which directs laser light to a measuring subject placed in a measuring space from a plurality of directions by using a light projector so that a light receiver detects reflected light derived from said laser light from said light projector reflected by said measuring subject to generate a three-dimensional shape data of said measuring subject, comprising:

a controller which, prior to measurements on said measuring subject, controls said light projector and said light receiver so as to measure a calibration-use subject placed in said measuring space from said plurality of directions;

a data processor which finds a conversion parameter used for converting measured data related to said calibration-use subject, obtained respectively in said plurality of directions, to three-dimensional shape data in a world coordinate system; and

a memory storing said conversion parameter;

wherein

said three-dimensional shape data is generated by data-converting said measured data related to said calibration-use subject, obtained respectively in said plurality of directions, by the use of said conversion parameter.

2. The three-dimensional shape-measuring system according to claim 1, wherein,

said data processor finds a conversion parameter used for calibrating relative position and orientation when measuring operations are carried out respectively in said plurality of directions.

3. The three-dimensional shape-measuring system according to claim 1, further comprising:

a rotation stage which rotates said measuring subject located in said measuring space,

wherein said data processor finds the position of the rotation axis of said rotation stage from measured data related to said calibration-use subject obtained respectively in said plurality of directions to find a conversion parameter used for rotation-shifting measured data around said rotation axis.

4. The three-dimensional shape-measuring system according to claim 1, wherein,

said data processor finds a conversion parameter used for composing measured data related to said calibration-use subject obtained respectively in said plurality of directions.

5. The three-dimensional shape-measuring system according to claim 4, wherein,

said data processor finds a conversion parameter which compares measured data related to said calibration-use subject obtained respectively in said plurality of directions with known data of said calibration-use subject to make said measured data closer to said known data.

6. The three-dimensional shape-measuring system according to claim 1, wherein,

said measured data contains information related to measuring magnifications used when measuring operations are carried out respectively in said plurality of directions, and

said data processor processes said measured data in accordance with said measuring magnifications.

7. A three-dimensional shape-measuring method, which directs laser light to a measuring subject placed in a measuring space by using a light projector so that a light receiver detects reflected light reflected by said measuring subject to measure said measuring subject in a plurality of directions by using a measuring device for measuring a three-dimensional shape of said measuring subject, thereby generating three-dimensional shape data of said measuring subject on the basis of measured data obtained respectively in said plurality of directions, comprising the steps of:

(a) placing a calibration-use subject in said measuring space prior to measurements on said measuring subject;

(b) measuring said calibration-use subject in said plurality of directions by using said measuring device;

(c) finding a conversion parameter used for converting measured data related to said calibrating-use subject, obtained respectively in said plurality of directions, to three-dimensional shape data in a world coordinate system;

(d) storing said conversion parameter; and

(e) upon measuring said measuring subject, generating three-dimensional shape data of said measuring subject by data-converting said measured data related to said measuring subject, obtained respectively in said plurality of directions, by the use of said conversion parameter.

8. The three-dimensional shape-measuring method according to claim 7, wherein

said step (c) includes the step of finding a parameter used for calibrating relative position and orientation when measuring operations are carried out respectively in said plurality of directions, thereby finding said conversion parameter.

9. The three-dimensional shape-measuring method according to claim 7, wherein

said step (a) includes the step of placing said calibration-use subject on a rotation stage provided in said measuring space,

said step (b) includes the step of rotating said rotation stage, and

said step (c) includes the step of finding the position of the rotation axis of said rotation stage from said measured data related to said calibration-use subject obtained respectively in said plurality of directions to find a parameter used for rotation-shifting said measured data around said rotation axis, thereby finding said conversion parameter.

10. The three-dimensional shape-measuring method according to claim 7, wherein

said step (c) includes the step of finding a parameter used for composing said measured data related to said calibration-use subject obtained respectively in said plurality of directions, thereby finding said conversion parameter.

11. The three-dimensional shape-measuring method according to claim 10, wherein

said step (c) includes the step of finding a parameter which compares said measured data related to said calibration-use subject obtained respectively in said plurality of directions with known data of said calibration-use subject to make said measured data closer to said known data, thereby finding said conversion parameter.

12. The three-dimensional shape-measuring method according to claim 7, wherein

said measured data related to said calibration-use subject contains information related to measuring magnifications used when measuring operations are carried out respectively in said plurality of directions, and

said step (c) includes the step of processing said measured data in accordance with said measuring magnifications, thereby finding said conversion parameter.