Resolver offset detection
AssigneeFord Global Technologies, LLC
InventorsJonathan Hair, Jonathan Andrew Butcher, Mohammad Sameer Khan, Brendan F. Diamond
Life of this patent
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Abstract
A vehicle includes an electric machine having a rotor and a stator, a resolver that measures a position of the rotor relative to the stator, and a controller. The controller, based on the position and a resolver offset, injects a first current having only a d-axis component into the electric machine, and responsive to detecting a first motion output of the electric machine being greater than a threshold, adjusts the resolver offset according to a magnitude and direction of the first motion output.
Claims18
A vehicle comprising:
- an electric machine having a rotor and a stator;
- a resolver configured to measure a position of the rotor relative to the stator;
- and
- a controller programmed to,
- based on the position and a resolver offset, inject a first current having only a d-axis component into the electric machine, and
- responsive to detecting a first motion output of the electric machine being greater than a threshold, adjust the resolver offset according to a magnitude and direction of the first motion output, wherein the first motion output includes at least one of a speed output or a torque output.
A method for controlling an electric machine of a vehicle comprising:
- while the vehicle is parked, repeatedly injecting current into the electric machine having only a d-axis component until motion output of a rotor of the electric machine corresponding to the current is less than a threshold.
A device for measuring a resolver offset of a resolver of an electric machine of a vehicle, the device comprising:
- a controller programmed to, responsive to a resolver offset testing condition being met, command that a first current having only a d-axis component be injected into the electric machine, and responsive to detecting a first motion output of the electric machine being greater than a threshold, adjust the resolver offset according to a magnitude and direction of the first motion output.
Dependencies are inferred from the claim text.