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US 8,897,954 B2Granted
Method for calibrating position sensor on electric motor
AssigneeDeere & Company
InventorsEric R. Anderson, Zimin Wu Vilar
Life of this patent
Estimating the term…
Abstract
A method is provided of calibrating a position sensor of an electric motor of a vehicle.
Claims22
A vehicle including:
- a chassis;
- at least one ground engaging mechanism configured to propel the chassis over the ground;
- a tool supported by the chassis to move material;
- at least one electric motor supported by the chassis and configured to convert electrical power into mechanical power, the motor having a rotor and a stator, the rotor having a magnetic field and the stator having a magnetic field;
- a sensor configured to provide an indication of the relative position of the rotor to the stator;
- and
- a controller controlling at least one of the magnetic field of the rotor and the magnetic field of the stator to cause an angular difference between the magnetic fields of the rotor and the stator, the controller controlling the angular difference based on a calibration test of the sensor wherein the controller calculates an error in the indicated relative position of the rotor in response to a torque applied to the rotor, wherein the controller is operative to operate the motor at a first speed and to increase the speed of the motor from the first speed to a second speed during the calibration test.
4 more elements
A method of calibrating a position sensor on a vehicle, the vehicle including a chassis, a ground engaging mechanism to propel the chassis, a tool supported by the chassis to move material, and at least one electric motor having a rotor and a stator for converting electrical power to mechanical power, the method including:
- receiving, by a controller of the vehicle, an indication of the relative position of the rotor to the stator provided by a sensor, the rotor having a magnetic field and the stator having a magnetic field;
- determining, by the controller, an offset of the indicated relative position of the rotor to the stator in response to a torque applied to the rotor, the determining the offset including operating the motor at a first speed and increasing the speed of the motor from the first speed to a second speed;
- and
- controlling, by the controller, an angular difference between the magnetic field of the rotor and the magnetic field of the stator based on the determined offset.
1 more element
A vehicle including:
- a chassis;
- at least one ground engaging mechanism configured to propel the chassis over the ground;
- a tool supported by the chassis to move material;
- at least one electric motor supported by the chassis and configured to convert electrical power into mechanical power, the motor having a rotor and a stator, the rotor having a magnetic field and the stator having a magnetic field;
- a sensor configured to provide an indication of the relative position of the rotor to the stator;
- and
- a controller controlling at least one of the magnetic field of the rotor and the magnetic field of the stator to cause an angular difference between the magnetic fields of the rotor and the stator, the controller controlling the angular difference based on a calibration test of the sensor, wherein the controller calculates the error in the indicated relative position of the rotor to the stator based on an acceleration rate of the motor.
4 more elements
Dependencies are inferred from the claim text.