Position detection apparatus with correction for non-linear sensor regions

摘要

A position determining apparatus including a magnet that is attached to a movable member which moves along a predefined path of finite length. An array of magnetic field transducers are located adjacent to the predefined path. The transducers provide a bipolar output signal as the magnet approaches, passes and moves away from each transducer. A correction mechanism is provided to correct for residual error caused by the non-linearity of the transducers. The correction mechanism preferably approximates the residual error with a predetermined function, and applies correction factors that correspond to the predetermined function to offset the residual error. By correcting for the non-linearity of the transducers, the length of the magnet may be reduced and/or the spacing of the transducers may be reduced.