US 6,577,985 B2 · Scalable code absolute logic function (SCALF) encoder

Abstract

An inventive encoding system that expects, accepts and interprets both normal and abnormal states of a sensor array, and that preferably further recognizes a zero state as a malfunction. The system is “absolute,” in that it allows detection of the best fit detectable position of a movable object with an accuracy equal to the resolution which is equal to one-half the physical displacement of sensors or sources in an array. Such absolute references may be used to define a position detector which properly detects the position of an object after power is applied, even though the object may have moved further after power is removed. As a result, the inventive encoder does not require a battery back-up to detect position accurately after a power failure. This functionality is highly advantageous when detecting shaft position of a multi-turn shaft. The inventive encoding system is also scalable so that there are few limitations in deployment. Truth table logic is employed in a logic function that is designed to implement the foregoing attributes of the inventive encoding system.

Claims34

Dependent claims

A method for encoding a current state of an array of elements, each element currently in either a high or low condition, the method comprising:

(a) identifying a set of expected valid normal detected states of the array, the set of expected valid normal detected states excluding a state in which all elements are detected to be in low condition;
(b) identifying a set of expected valid abnormal detected states for the array, the set of expected valid abnormal detected states also excluding a state in which all elements are detected to be in low condition;
(c) identifying a set of events to which normal and abnormal detected states of the array are to correspond;
(d) developing a truth table in which each event in the set thereof corresponds to at least one expected valid normal detected state of the array and at least one expected valid abnormal detected state of the array;
(e) polling the current state of the array;
and
(f) identifying a current event from the set of events based upon the truth table in view of current state of the array as polled in step (e).

4 more elements

A method for encoding a positional state of a hierarchical gear assembly, the gear assembly comprising a plurality of interrelated rotary gears, one complete revolution of a lower gear causing a predetermined amount of rotation less than one revolution in an immediately higher gear, the method comprising:

(a) deploying at least one source on each rotary gear;
(b) deploying a sensor array for each rotary gear, each array comprising at least three sensors in sensory communication with the sources on its corresponding rotary gear;
(c) identifying a set of expected valid normal detected states for each array;
(d) identifying a set of expected valid abnormal detected states for each array;
(e) identifying a set of positional states of the hierarchical gear assembly to which combinations of normal and abnormal detected states in each array are to correspond;
(f) developing a truth table in which each positional state of the hierarchical gear assembly in the set thereof corresponds to a combination of at least one expected valid normal detected state of each array and at least one expected valid abnormal detected state of each array;
(g) polling the current state of each array;
and
(h) identifying a current positional state for the hierarchical gear assembly from the truth table based upon the combined current states of the arrays as polled in step (g).

6 more elements

Dependencies are inferred from the claim text.

Scalable code absolute logic function (SCALF) encoder

Life of this patent

Scalable code absolute logic function (SCALF) encoder

Life of this patent

Abstract

Claims34