Method and device for enlarging the measurement volume of an optical measurement system

• US 7,280,226 B2
• Filed: 11/22/2002
• Issued: 10/09/2007
• Est. Priority Date: 11/22/2001
• Status: Expired due to Term

• Current Assignee: 3D Scanners Ltd. (Nikon Corporation)
• Original Assignee: Metris Engineering Services
• Inventors: Van Den Bossche, Alex
• Primary Examiner(s): Toatley, Jr.; Gregory J.
• Assistant Examiner(s): Akanbi; Isiaka O
• Application Number:
  US10/496,576
• Publication Number:
  US 20050062983A1
• Time in Patent Office: 1,782 Days
• Field of Search: 356/375, 356/426, 356/601
• US Class Current: 356/601
• CPC Class Codes: G01B 11/002 for measuring two or more coordinates
• CPC Class Codes: G01C 11/02 Picture taking arrangements specially adapted for photogrammetry or photographic surveying, e.g. controlling overlapping of pictures

Abstract

The invention concerns a method for enlarging the measuring volume of an optical measuring system and, on such a measuring system, at least one camera (2, 3, 4) to determine the position of at least one object (1) in relation to a base co-ordinate system, whereby, in order to measure the position of a point which is not situated within the field of vision of said camera (2, 3, 4), this camera (2, 3, 4) is moved in relation to a reference (7) having a fixed position in relation to said base co-ordinate system towards a measuring position, so that said point is situated within the field of vision of the camera (2, 3, 4), whereby the movement of the camera (2, 3, 4) in relation to said reference (7) is determined and the position of said point is perceived with said camera (2, 3, 4) in order to determine its position in relation to said base co-ordinate system, taking into account the movement of the camera (2, 3, 4).

Claims

1. Method for enlarging the measuring volume of an optical measuring system with at least one camera (2, 3, 4) to determine the position of at least one point of an object (1) in relation to a base co-ordinate system,

characterised in that, in order to determine the position of a point which is not situated within the field of vision of said camera (2, 3, 4), this camera (2, 3, 4) is moved in relation to a reference (7), having a fixed position in relation to said base co-ordinate system, towards a measuring position, so that said point comes within the field of vision of the camera (2, 3, 4),

whereby the movement of the camera (2, 3, 4) in relation to said reference (7) is determined and the position of said point is perceived with said camera (2, 3, 4) in order to calculate its position in relation to said base co-ordinate system, taking into account the movement of the camera (2, 3, 4), and

at least one part (12) of each of said reference organs (8, 9, 10) is rotated in relation to said fixed position, so that the reference points (13, 14, 15) thereof can be perceived by said camera (2, 3, 4).

2. Method according to claim 1, characterised in that said part (12) of each of the above-mentioned reference organs (8, 9, 10) is driven so as to move it as a function of the movement of said camera (2, 3, 4), whereby the whole is oriented such that the reference points (13, 14, 15) will at all times remain within the field of vision of the camera (2, 3, 4).

3. Optical measuring system with at least one camera (2, 3, 4) for measuring the position of a point of an object (1), in particular an optical measuring system for applying a method for enlarging the measuring volume of the optical measuring system to determine the position of at least one point of an object (1) in relation to a base co-ordinate system, wherein to determine the position of a point which is not situated within the field of vision of said camera (2, 3, 4), the camera (2, 3, 4) is moved in relation to a reference (7), having a fixed position in relation to said base co-ordinate system, towards a measuring position, so that said point comes within the field of vision of the camera (2, 3, 4), and whereby the movement of the camera (2, 3, 4) in relation to said reference (7) is determined and the position of said point is perceived with said camera (2, 3, 4) in order to calculate its position in relation to said base co-ordinate system, taking into account the movement of the camera (2, 3, 4), the optical measuring system comprising at least one reference organ (8, 9, 10) which must be placed in a fixed position in the measuring volume of the optical measuring system, whereby this reference organ (8, 9, 10) has at least three reference points (13, 14, 15) which make it possible to determine the position of the reference organ (8, 9, 10) by means of said camera (2, 3, 4), whereby means are further provided which make it possible to move the camera (2, 3, 4) in relation to said reference organ (8, 9, 10) and to measure this movement,

whereby said reference organ (8, 9, 10) has a fastening part (11) and a reference part (12), whereby the latter comprises the reference points (13, 14, 15) of the reference organ, and whereby the reference part (12) can be rotated in relation to the fastening part (11).

4. Optical measuring system according to claim 3, characterised in that said camera (2, 3, 4) is mounted such that it can be rotated in relation to the environment, whereby means are provided to determine its rotational movement.

5. Optical measuring system according to claim 4, characterised in that said camera (2, 3, 4) is mounted such that it can be rotated in relation to a foot (19).

6. Optical measuring system according to claim 4, characterised in that said camera (2, 3, 4) is driven by an electric motor in order to undergo said rotational movement.

7. Optical measuring system according to claim 4, characterised in that an angle encoder is provided in order to measure the rotational movement of said camera (2, 3, 4).