초록 ▼

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,

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.

대표청구항 ▼

[ What is claimed is:] [1.] Apparatus for determining a position of a member movable along a defined path, comprising:field producing means attached to the member for producing a magnetic field;an array of magnetic field transducers located adjacent the defined path at known locations, each transduc

[ What is claimed is:] [1.] Apparatus for determining a position of a member movable along a defined path, comprising:field producing means attached to the member for producing a magnetic field;an array of magnetic field transducers located adjacent the defined path at known locations, each transducer providing a bipolar output signal as the field producing means approaches, passes and moves away from each transducer;each of the transducers providing an output signal value for a first position of the field producing means; anddetermining means for determining the first position of the field producing means by calculating a ratio of the output signal values of selected transducers, and applying a selected correction factor to the ratio to determine the first position.