Kenyon & Kenyon LLP
Method for initializing a position-measuring system
A method is for initializing a position-measuring system for an object movable in at least two degrees of freedom relative to a measuring frame. The position-measuring system includes one position-measuring device per degree of freedom, including a scale having an incremental track for measuring relative positions and an absolute track for measuring absolute positions, as well as scanning heads, assigned to the scales, for reading the incremental tracks and absolute tracks. In an initialization step, the incremental tracks are evaluated using a first evaluation procedure having a large tolerance with respect to the alignment of scanning head and associated scale, and in so doing, approximate absolute positions are determined per degree of freedom. In an alignment step, the movable object is aligned relative to the measuring frame based on the approximate position. In an acquisition step, the absolute tracks are evaluated using a second evaluation procedure having a low tolerance with respect to the alignment of scanning head and associated scale, and precise absolute positions are determined for each degree of freedom.
Dr. Johannes Heidenhain GmbH
G G
G01D G01D
inventional inventional
Wolfgang Kai
Holzapfel Rascher