Position indicating system
AssigneeGeneral Electric Company
InventorAjith K. Kumar
Life of this patent
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Abstract
A rotatable member having multiple discrete positions between opposite ends of a normal path of movement is provided with two (or three) parallel, encoded tracks having different patterns of distinct, serial sections. These tracks cooperate with relatively stationary probes of a position sensor. As the rotatable member moves from position to position, the sensor will produce a family of two (or three) separate binary signals that changes states as the probes detect boundaries between successive sections of the tracks with which they respectively communicate, and the patterns of the encoded sections are so selected that the sequence of state changes when the rotatable member is approaching a predetermined mid position will differ from the sequence when the member is moving away therefrom.
Claims20
In a system for indicating the relative physical displacement between first and second members, one of which is reciprocally movable along a given path through multiple positions with respect to the other member, which positions include a first position at one end of the normal travel of said one member, a last position at the opposite end of the normal travel, and a transition position in between said first and last positions:
- (a) at least two parallel encoding tracks provided on said first member, each of said tracks being encoded to form a series of distinct sections extending generally in the direction of said given path, with the respective sections thereof being located in accordance with a predetermined pattern that differs from the pattern of the encoded sections of any other track;
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- (b) a position sensor including at least two probes mounted on said second member in communication, respectively, with said encoding tracks, each probe being adapted to discriminate between successive sections of the corresponding track as said one member moves from position to position;
- (c) said position sensor being operative to produce a family of at least two separate binary signals the present states of which depend, respectively, on which encoded sections of said tracks said probes last communicated with, whereby the state of each of said signals will change each time the corresponding probe senses a different encoded section as said one member moves from position to position, and the predetermined patterns of the respective tracks being so selected that said family of binary signals will change states at least once as said one member moves from any one of said positions to the next position and such state changes occur in a first predetermined repetitive sequence so long as said one member is moving in a direction from either end position toward its transition position, a second predetermined repetitive sequence different than said first sequence so long as said one member is moving in a direction away from its transition position toward either end position, and a third unique sequence different than either said first or second sequence when said one member is moving through a predetermined limited portion of its travel that includes its transition position.
In a system for indicating the relative physical displacement between first and second members, one of which is reciprocally movable along a given path through multiple discrete positions with respect to the other member, which positions include a first position at one end of the normal travel of said one member, a last position at the opposite end of the normal travel, and a predetermined intermediate position between said first and last positions:
- (a) three parallel encoding tracks provided on said first member, each of said tracks being encoded to form a series of distinct sections extending generally in the direction of said given path, with the respective sections thereof being located in accordance with a predetermined pattern that differs from the pattern of the encoded sections of any other track;
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- (b) a position sensor including three probes mounted on said second member in communication, respectively, with said encoding tracks, each probe being adapted to discriminate between successive sections of the corresponding track as said one member moves from position to position;
- (c) said position sensor being operative to produce a family of three separate binary signals the present states of which depend, respectively, on which encoded sections of said tracks said probes last communicated with, whereby the state of each of said signals will change each time the corresponding probe senses a different encoded section as said one member moves from position to position,
- (d) the predetermined patterns of the respective tracks being so selected that said family of binary signals will change states at least once as said one member moves from any one of said positions to the next position and such state changes occur in a first predetermined sequence so long as said one member is moving in a direction from said first position toward its intermediate position, a second predetermined sequence so long as said one member is moving in a direction from said last position toward its intermediate position, a third predetermined sequence so long as said one member is moving in a direction away from its intermediate position toward said first position, a fourth predetermined sequence so long as said one member is moving in a direction away from its intermediate position toward said last position, and a fifth predetermined sequence when said one member is moving through a predetermined limited portion of its travel that includes its intermediate position, each of said first, second, third, fourth, and fifth sequences differing from any one of the others.
Dependencies are inferred from the claim text.