Patent ID: 6418388
Filing Date: 2002-07-09
Classification: G01D

Abstract:
An arrangement for offset compensation of two orthogonal sensor signals S(x) and S(y), which are supplied by two sensors (2,3) and are preferably designed for angle measurements, the offset compensation taking place in dependence on the geometric arrangement of three pairs of test values P1(x1, y1), P2(x2, y2) and P3(x3, y3) of the sensor signals S(x) and S(y) in a system of coordinates, the center of a circle on which the three pairs of test values P1(x1, y1), P2(x2, y2) and P3(x3, y3) are situated in the system of coordinates having center coordinates &Dgr;x and &Dgr;y relative to the origin of the system of coordinates, characterized in that correction means (10) are provided which carry out a sign determination of the values &Dgr;x and &Dgr;y of the center coordinates of the circle on which the three pairs of test values P1(x1, y1), P2(x2, y2) and P3(x3, y3) are situated in a repetitive cycle in each measuring cycle, while in each measuring cycle at least one of the pairs of test values differs from the pair of test values used in the preceding measuring cycle, and which means (10) generate correction signals Kx and Ky with which the sensor signals S(x) and S(y) are complemented, in that the correction means (10) in every measuring cycle increase or decrease the offset correction signal Kx by a correction value KWx compared with the offset correction signal Kx of the previous measuring cycle in dependence on the sign of the center coordinate &Dgr;x, and in that the correction means (10) in every measuring cycle in a similar manner increase or decrease the offset correction signal Ky by a correction value KWy compared with the offset correction signal Ky of the previous measuring cycle in dependence on the sign of the center coordinate &Dgr;y.