INTERPOLATION APPARATUS FOR ENCODER, CONTROLLING METHOD OF INTERPOLATION APPARATUS FOR ENCODER, NON-TRANSITORY STORAGE MEDIUM STORING CONTROLLING PROGRAM OF INTERPOLATION APPARATUS FOR ENCODER AND ENCODER

摘要

An AD converter acquires first and second input values. A first multiplication unit multiplies a first tangent value, which is based on a first boundary angle based on a phase range of a reference value, by the reference value to calculate a first threshold value. A second multiplication unit multiplies a second tangent value, which is based on a second boundary angle based on the phase range, by the reference value to calculate a second threshold. A comparison unit determines whether the comparison value is within a particular phase range specified by the first and the second thresholds. The comparison unit determines magnitude of the comparison value when the comparison value is not within the particular phase range. A phase estimation unit updates the particular phase range to a phase range adjacent to a direction corresponding to the result of determination.