Method for initializing a position-measuring system
First Claim
1. A method 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 including at least one position-measuring device per degree of freedom, each position-measuring device having a scale including an incremental track for measuring a relative position and an absolute track for measuring an absolute position and scanning heads, corresponding to the scales, for reading the incremental track and absolute track, comprising:
- an initialization step in which at least one of the incremental tracks and the absolute tracks are evaluated with a first evaluation procedure to form an evaluation result;
an alignment step in which the movable object is aligned relative to the measuring frame based on the evaluation result; and
an acquisition step in which the absolute tracks are evaluated with a second evaluation procedure having a small tolerance with respect to alignment of scanning head and the corresponding scale to determine a precise absolute position for each degree of freedom.
1 Assignment
0 Petitions
Accused Products
Abstract
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.
-
Citations
20 Claims
-
1. A method 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 including at least one position-measuring device per degree of freedom, each position-measuring device having a scale including an incremental track for measuring a relative position and an absolute track for measuring an absolute position and scanning heads, corresponding to the scales, for reading the incremental track and absolute track, comprising:
-
an initialization step in which at least one of the incremental tracks and the absolute tracks are evaluated with a first evaluation procedure to form an evaluation result; an alignment step in which the movable object is aligned relative to the measuring frame based on the evaluation result; and an acquisition step in which the absolute tracks are evaluated with a second evaluation procedure having a small tolerance with respect to alignment of scanning head and the corresponding scale to determine a precise absolute position for each degree of freedom. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
-
-
11. A method 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 including at least one position-measuring device per degree of freedom, each position-measuring device having a scale including an incremental track for measuring a relative position and an absolute track for measuring an absolute position and scanning heads, corresponding to the scales, for reading the incremental track and absolute track, comprising:
-
evaluating, in an initialization step, at least one of (a) the incremental track and (b) the absolute track of each position-measuring device with a first evaluation procedure to form an evaluation result; aligning, in an alignment step, the movable object relative to the measuring frame based on the evaluation result; and evaluating, in an acquisition step, the absolute track of each position-measuring device with a second evaluation procedure having a small tolerance with respect to alignment of scanning head and the corresponding scale to determine a precise absolute position for each degree of freedom. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20)
-
Specification