Method and Arrangement for Measuring the Position of a Circular Object
First Claim
1. A method for measuring the position of a circular object, such as the end or end shield of a paper or board reel, using a measuring device comprising:
- arranging positions of the measuring device and the circular object to be such that the object is in a detection area of the measuring device;
moving the detector along such a circular path that intersects the curve of the circle described by the edge of the object;
measuring with the measuring device an angular position of the detector using the curve of the circle over which the detector travels;
detecting intersection points of the curve travelled by the detector and the edge of the object;
determining a location of the centre point of the object on the basis of;
a) the radius of the circular path travelled by the detector, and the location of the centre point of the circular path, b) the location of the tool point of a grab device for grasping the object, c) the assumed radius of the object, and d) the locations of the detected intersection points, determining the position of the centre point of the object in the set of coordinates of the grab device.
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Accused Products
Abstract
Method and arrangement for measuring the position of the end shields of a paper, pulp, or board reel relative to the grab (1, 2) transporting it, when an end shield is attached to the grab (1, 2). During measurement, a detector (7) is moved along such a curve of a circle that can be assumed to intersect the curve of the circle described by the edge of the object. The angular position of the detector (7) is measured using the curve of the circle over which it travels and the intersection points (x1, z1; x2, z2) of the curve travelled by the detector (7) and the edge of the object are detected. The location of the centre point (x0, z0) of the object is calculated on the basis of a) the radius of the circle travelled by the detector and the location (xm, zm) of the centre point of the circle, b) the location (xt, zt) of the tool point, c) the assumed radius of the object, and d) the locations (x1, z1; x2 z2) of the detected intersection points. Finally, the position of the centre point (x0, z0) of the object in the set of co-ordinates of the grab is calculated.
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Citations
15 Claims
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1. A method for measuring the position of a circular object, such as the end or end shield of a paper or board reel, using a measuring device comprising:
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arranging positions of the measuring device and the circular object to be such that the object is in a detection area of the measuring device;
moving the detector along such a circular path that intersects the curve of the circle described by the edge of the object;
measuring with the measuring device an angular position of the detector using the curve of the circle over which the detector travels;
detecting intersection points of the curve travelled by the detector and the edge of the object;
determining a location of the centre point of the object on the basis of;
a) the radius of the circular path travelled by the detector, and the location of the centre point of the circular path, b) the location of the tool point of a grab device for grasping the object, c) the assumed radius of the object, and d) the locations of the detected intersection points, determining the position of the centre point of the object in the set of coordinates of the grab device. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. An apparatus for measuring the position of a circular object, such as the end or end shield of a paper, pulp, or board reel, comprising:
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a frame structure;
a grab device for grasping the object, the grab device having a defined tool point;
a measuring device;
a means for positioning the circular object and the measuring device such that the object is in a measuring area of the measuring device;
a measuring arm arranged to rotate around a rotation shaft fitted to the frame structure, the measuring device measuring an angle of rotation of the measuring arm around the rotation shaft; and
at least one detector fitted to the measuring arm to detect the edge of the end shield when the detector travels past the edge. - View Dependent Claims (10, 11, 12, 13, 14, 15)
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Specification