Patent ID: 6401052
Filing Date: 2002-06-04
Classification: G01D

Abstract:
A method for determining a position signal, comprising:scanning a material measure using two primary detectors, the material measure being moved relative to the primary detectors, the material measure having graduations that are arranged equidistant from one another, the primary detectors providing measurement signals corresponding to the graduations, the measurement signals being periodic, given uniform relative motion of the material measure, and being sinusoidal, the measurement signals further being phase-displaced by 90Â° relative to one another, the material measure executing a relative motion of one graduation during one period of the measurement signals, an updating taking place concerning the graduation to which the measurement signals are currently allocated; determining a rough angle from the measurement signals as a function of predetermined graduation-specific amplitudes and offsets of the measurement signals, and as a function of a phase displacement of the measurement signals relative to one another; determining a position angle inside the graduation to which the measurement signals are currently allocated, the position angle being determined from the rough angle as a function of predetermined rough angle corrections values that are specific to the rough angle and that are independent of the graduation; and determining the position signal from the position angle and the graduation to which the determined measurement signals are currently allocated.