System and method of determining a representative measurement from multiple independent measurements of electric machine speed
AssigneeFord Global Technologies, LLC
InventorsDev Saberwal, Christopher Golecki
Life of this patent
Estimating the term…
Abstract
A vehicle includes first and second electric machines constrained to rotate in unison and configured to power a common axle. A controller is programmed to, in response to activation of the vehicle, select one of the first and second speed sensors as a representative speed sensor, and, in response to the electric machines being in speed control, command speeds to the first and second electric machines based on a difference between a target speed of the electric machines and a measured speed of the representative speed sensor.
Claims18
A control system for a vehicle having first and second electric machines configured to power a common axle, comprising:
- a controller programmed to:
- in response to the first and second electric machines being in speed control, command speeds to the first and second electric machines based on a difference between a target speed of the electric machines and a measured speed from a selected one of first and second speed sensors, wherein a ratio of speed values detected by the selected one and average speed values detected by the first and second sensors is less than the ratio of the other of the first and second sensors, and
- select the one of the first and second speed sensors by identifying one of the first and second speed sensors as having a greatest number of accumulated points for a predefined sampling duration, the accumulated points for each of the first and second speed sensor being based on the ratio.
A vehicle comprising:
- a driven axle;
- first and second electric machines configured to power the driven axle, wherein the first and second electric machines have rotor shafts constrained to rotate in unison, and the first and second electric machines have first and second speed sensors, respectively;
- and
- a controller programmed to:
- in response to activation of the vehicle, select one of the first and second speed sensors having a greatest number of accumulated points for a predefined sampling duration, wherein the accumulated points for each of the first and second speed sensors is based on (i) a variance that is a ratio of a speed value for the speed sensor and an average speed value for both of the speed sensors and (ii) a noise factor associated with the speed sensor;
- and
- in response to the electric machines being in speed control, command speeds to the first and second electric machines based on a difference between a target speed of the electric machines and a measured speed of the one of the first and second speed sensors but not the other of the first and second speed sensors.
A method of controlling an electric vehicle having first and second electric machines, the method comprising:
- selecting one of first and second speed sensors based on (i) a difference between a speed value for the that speed sensor and an average speed for both of the speed sensors and (ii) a noise factor associated with the one of the speed sensors;
- commanding speeds to the first and second electric machine based on a difference between a target speed of the electric machines and a measured speed of the one of the first and second speed sensors but not the other of the first and second speed sensors;
- and
- in response to the electric machines being commanded to an idle speed, selecting one of the first and second speed sensors having a greatest number of accumulated points for a first predefined sampling duration occurring when at the idle speed, wherein the accumulated points of the second duration for each of the first and second speed sensor is based on (i) a variance that is a ratio of a speed value for that speed sensors and an average speed for both of the speed sensors and (ii) a noise factor associated with that speed sensor.
Dependencies are inferred from the claim text.