Resolver offset detection
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.
1. 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.
2. The vehicle of claim 1 , wherein the controller is further programmed to, based on the position and the resolver offset as adjusted, inject a second current having only a d-axis component into the electric machine.
3. The vehicle of claim 2 , wherein the controller is further programmed to, responsive to detecting a second motion output of the electric machine being greater than the threshold, further adjust the resolver offset according to a magnitude and direction of the second motion output.
4. The vehicle of claim 3 , wherein the controller is further programmed to responsive to the magnitude of the second motion output being less than the magnitude of the first motion output, inject a third current having an increased magnitude from the second current into the electric machine.
5. The vehicle of claim 2 , wherein the controller is further programmed to normalize a plurality of motion outputs of the electric machine.
6. The vehicle of claim 1 , wherein the controller is further programmed to adjust the resolver offset according to a magnitude of the first current.
7. The vehicle of claim 1 , wherein the controller is further programmed to adjust the resolver offset according to a magnitude of the first current based on a lookup table.
8. 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.
9. The method of claim 8 , wherein the motion output is speed output or torque output.
10. The method of claim 8 further comprising updating a resolver offset based on the motion output.
11. 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.
12. The device of claim 11 , wherein the controller is further programmed to, based on resolver offset as adjusted, inject a second current having only a d-axis component into the electric machine.
13. The device of claim 12 , wherein the controller is further programmed to, responsive to detecting a second motion output of the electric machine being greater than the threshold, further adjust the resolver offset according to a magnitude and direction of the second motion output.
14. The device of claim 13 , wherein the controller is further programmed to responsive to the magnitude of the second motion output being less than the magnitude of the first motion output, inject a third current having an increased magnitude from the second current into the electric machine.
15. The device of claim 12 , wherein the controller is further programmed to normalize a plurality of motion outputs of the electric machine.
16. The device of claim 11 , wherein the first motion output includes at least one of a speed output or a torque output.
17. The device of claim 11 , wherein the controller is further programmed to adjust the resolver offset according to a magnitude of the first current.
18. The device of claim 11 , wherein the controller is further programmed to adjust the resolver offset according to a magnitude of the first current based on a lookup table.