Compensated resolver feedback
AssigneeGeneral Electric Company
InventorsEdward L. Denham, Michael J. Tuso
Life of this patent
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Abstract
A method and apparatus by which the output value of a resolver position detection system is compensated for systematic phase shift errors produced by signal conditioning circuitry through which the signal passes.
Claims10
For use in conjunction with a resolver and its operative circuitry, the resolver being disposed for monitoring the relative position of an object, a method providing a position indicative value compensated for errors caused by systematic phase shifts in the resolver output signal with respect to reference signals, comprising the steps of:
- (a) providing the reference signals as excitation for the resolver, the resolver being responsive to produce said output signal such that its phase relationships with the reference signals are indicative of the monitored position;
- (b) passing at least one reference signal through substantially the same circuit path as that through which the resolver output signal passes to thereby generate a phase shift value indicative of the amount of systematic phase shift induced by said circuit path;
- (c) determining the amount of phase shift between the resolver output signal and said at least one reference signal after passing the resolver output signal through said circuit path, to provide a value indicative of the apparent monitored position;
- and
- (d) subtracting said phase shift value of step (b) from the apparent position indicative value of step (c) to provide a compensated position value indicative of the true monitored position.
For operation in combination with a resolver disposed for monitoring the relative position of an object and with signal conditioning circuitry for conditioning the resolver output signal, apparatus providing a position indicative value compensated for phase shift errors induced by said signal conditioning circuitry, comprising:
- (a) means providing at least one reference signal as excitation for the resolver, the resolver being responsive to produce said output signal such that its phase relationship with the reference signal is indicative of the object's position;
- (b) switching means receiving the reference signal and the resolver output signal for selecting one or the other to pass through the signal conditioning circuitry;
- (c) phase shift detecting means receiving the signal from the signal conditioning circuitry to provide an output value indicative of the phase relationship between the reference signal and the received signal whereby the output value is indicative of the object's apparent position when the received signal is the resolver output signal and indicative of phase shift error when the received signal is the reference signal;
- (d) means for storing the output value from said phase shift determining means when said value is indicative of the phase shift error;
- and,
- (e) means for subtracting the stored value from the apparent position indicative value to produce the compensated position indicative value.
Dependencies are inferred from the claim text.