Method and apparatus for determining the 3D coordinates of an object

1. A method for determining the 3D coordinates of an object ( 1 ), comprising:

a pattern ( 6 ) is projected onto the object ( 1 ) by a projector ( 3 );

a light reflected by the object ( 1 ) is captured by a camera ( 4 );

camera shots recorded by the camera ( 4 ) are evaluated,

reference marks ( 8 ) on and/or beside the object (i) are recorded by a reference camera ( 5 ) by reference camera shots, the reference camera having a larger field of view ( 9 ) than the camera ( 4 ),

the one and only reference camera ( 5 ) is connected with a 3D sensor ( 2 ) which comprises the projector ( 3 ) and the camera ( 4 ) so that the pattern ( 6 ) projected by the projector moves along with a movement of each of the projector ( 3 ), the camera ( 4 ) and the reference camera ( 5 ), and wherein a number and positioning of the reference marks ( 8 ) are chosen such that when the reference camera ( 5 ) changes position, a number of reference marks ( 8 ) are present for the reference camera ( 5 ) to detect, when capturing a subsequent picture of the object ( 1 ), and

wherein a contour ( 7 ′) of the pattern ( 6 ) from the projector ( 3 ) is greater than and encloses a field of view of the camera ( 4 ).

2. The method according to claim 1 , wherein the reference marks ( 8 ) are projected onto the object ( 1 ).

3. The method according to claim 2 , wherein the camera shots of the camera ( 4 ) and the reference camera shots of the reference camera ( 5 ) are effected at the same time.

4. The method according to claim 3 , wherein several shots of the camera ( 4 ) are put together.

5. The method according to claim 2 , wherein several shots of the camera ( 4 ) are put together.

6. The method according to claim 2 , wherein the camera shots of the camera ( 4 ) and the reference camera shots of the reference camera ( 5 ) are effected temporally offset.

7. The method according to claim 6 , wherein several shots of the camera ( 4 ) are put together.

8. The method according to claim 1 , wherein the camera shots of the camera ( 4 ) and the reference camera shots of the reference camera ( 5 ) are effected temporally offset.

9. The method according to claim 8 , wherein several shots of the camera ( 4 ) are put together.

10. The method according to claim 1 , wherein the camera shots of the camera ( 4 ) and the reference camera shots of the reference camera ( 5 ) are effected at the same time.

11. The method according to claim 10 , wherein several shots of the camera ( 4 ) are put together.

12. The method according to claim 1 , wherein several camera shots of the camera ( 4 ) are put together.

13. The method according to claim 1 , wherein in a first measurement run the positions of the reference marks ( 8 ) are detected and stored.

14. The method according to claim 1 , wherein the 3D coordinates of an object ( 1 ) are determined on the basis of stored positions of the reference marks ( 8 ).

15. An apparatus for determining the 3D coordinates of an object ( 1 ), in particular for carrying out the method according to claim 1 , comprising:

a projector ( 3 ) for projecting a pattern ( 6 ) onto the object ( 1 );

a camera ( 4 ) for recording the object ( 1 );

an evaluating means for evaluating the shots of the object ( 1 ); and

a reference camera ( 5 ) for recording reference marks ( 8 ) on and/or beside the object ( 1 ), which has a larger field of view ( 9 ) than the camera ( 4 ),

wherein the reference camera ( 5 ) is connected with a 3D sensor ( 2 ) which comprises the projector ( 3 ) and the camera ( 4 ) so that the pattern ( 6 ) projected by the projector moves along with a movement of each of the projector ( 3 ), the camera ( 4 ) and the reference camera ( 5 ), and

wherein a number and positioning of the reference marks ( 8 ) are chosen such that when the reference camera ( 5 ) changes position, a sufficient number of reference marks ( 8 ) are present for the reference camera ( 5 ) to detect, when capturing a subsequent picture of the object ( 1 ).

16. The apparatus according to claim 15 , comprising a projector for projecting the reference marks ( 8 ) onto the object ( 1 ).

17. The method of claim 1 , wherein the pattern ( 6 ) is moved along with the movement of the projector ( 3 ), the camera ( 4 ) and the reference camera ( 5 ) after the camera ( 4 ) has captured a part of the object ( 1 ) a first time and the projector ( 3 ), the camera ( 4 ), and the reference camera ( 5 ) are moving to take a subsequent picture of the object ( 1 ).

18. The method of claim 1 , wherein the projector ( 3 ), the camera ( 4 ) and the reference camera ( 5 ) are directly connected to each other.

19. The method of claim 1 , wherein when the reference camera ( 5 ) moves to a new location, the camera ( 4 ) and the projector ( 3 ) always move to a corresponding new location.

20. The method of claim 1 , wherein when the reference camera ( 5 ) moves to a new location, a location of the camera ( 4 ) or the projector ( 3 ) is always at least partially moved as well.