Patent ID: 6963820

Claim:
A method for determining the distance moved by a component while moving in a forward direction and operatively coupled to an analog encoder having analog first and second output signals in substantial quadrature comprising the steps of: a) calculating an inverse signal which is the inverse of the second output signal; b) calculating the distance moved by the component from a reference position using an ascending region of the first output signal until the first output signal reaches a first high level; c) then calculating the distance moved by the component from the position of the component when the first output signal reached the first high level using an ascending region of the second output signal until the second output signal reaches a second high level; d) then calculating the distance moved by the component from the position of the component when the second output signal reached the second high level using a descending region of the first output signal until the first output signal reaches a first low level; and e) then calculating the distance moved by the component from the position of the component when the first output signal reached the first low level using a descending region of the second output signal until the second output signal reaches a second low level after which steps b) through e) are repeated wherein the reference position becomes the position of the component when the second output signal reached the second low level, and wherein the first high level is the crossover level of the ascending first output signal and the inverse signal, wherein the second high level is the crossover level of the ascending second output signal and the first output signal, wherein the first low level is the crossover level of the descending first output signal and the inverse signal, and wherein the second low level is the crossover level of the descending second output signal and the first output signal.