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

Abstract

A method is provided 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 ).

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, comprising: 
 in order to determine the position of a point which is not situated within the field of vision of said camera ( 2 , 3 , 4 ), moving said camera ( 2 , 3 , 4 ) 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 position of the reference ( 7 ) in said measuring position is measured with the camera ( 2 , 3 , 4 ) such that    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 ).    
   
   
       2 . Method according to  claim 1 , characterised in that a fixed co-ordinate system is associated with said reference.  
   
   
       3 . Method according to  claim 1 , further comprising using a holder with a measuring point and at least three reference points which are not situated on a straight line, whereby said measuring point is placed against said point whose position needs to be determined, the positions of said reference points are subsequently measured by means of said camera ( 2 , 3 , 4 ) and the position of the point is calculated on the basis of the position of these reference points, whereby said reference points are perceived with the above-mentioned camera ( 2 , 3 , 4 ) and the camera ( 2 , 3 , 4 ) is automatically moved when the position of said holder is changed in order to keep the latter within the field of vision of the camera ( 2 , 3 , 4 ).  
   
   
       4 . Method according to  claim 1 , further comprising rotating said camera ( 2 , 3 , 4 ) such that said point to be measured will be situated within its field of vision.  
   
   
       5 . Method according to  claim 1 , further comprising forming said reference ( 7 ) of at least three reference organs ( 8 , 9 , 10 ) which are not situated on a straight line, provided in a fixed position in relation to the base co-ordinate system in said measuring volume.  
   
   
       6 . Method according to  claim 5 , wherein each of the reference organs ( 8 , 9 , 10 ) has at least three reference points ( 13 , 14 , 15 ) with a fixed position in relation to one another, whereby the position of these reference points ( 13 , 14 , 15 ) is measured in order to calculate the corresponding position of said reference organs ( 8 , 9 , 10 ).  
   
   
       7 . Method according to  claim 6 , further comprising rotating at least one part ( 12 ) of each of said reference organs ( 8 , 9 , 10 ) in relation to said fixed position, so that the reference points ( 13 , 14 , 15 ) thereof can be perceived by said camera ( 2 , 3 , 4 ).  
   
   
       8 . Method according to claim  15 , further comprising driving said part ( 12 ) of each of the above-mentioned reference organs ( 8 , 9 , 10 ) 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 ).