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US 12,594,938 B2Granted
Optimized electric machine stop position for loss reduction and vehicle launch
AssigneeDana Heavy Vehicle Systems Group, LLC
InventorsAhmad Ghaderi, William F. Waltz, Jeremy M. Frenznick
Life of this patent
Estimating the term…
Abstract
Methods and systems for controlling torque of an electric machine that propels a vehicle when the vehicle is stopped are described. The methods and systems may be applied to synchronous and induction electric machines that are configured to propel a vehicle. The methods and systems may allow a consistent amount of torque to be delivered by an electric machine when vehicle speed and electric machine speed is zero.
Claims19
A method for operating a vehicle, comprising:
- determining whether a road surface grade may be overcome while a speed of the vehicle is zero and a rotor of an electric machine of the vehicle is not positioned for the electric machine to generate its maximum torque at zero speed, and
- in response to determining that the road surface grade may not be overcome,
- opening a dog clutch, wherein the dog clutch includes teeth, and
- rotating the rotor to a predetermined angular position that increases torque output of the electric machine at zero speed, wherein the predetermined position is based on an angular orientation of the teeth of the dog clutch.
1 more element
A vehicle system, comprising:
- an electric machine configured to propel a vehicle;
- a driveline clutch;
- an inverter electrically coupled to the electric machine;
- and
- a controller including executable instructions stored in non-transitory memory that cause the controller to:
- retrieve one or more predetermined rotational positions from the non-transitory memory, wherein the predetermined rotational positions comprise rotor positions where maximum output torque is output by the electric machine;
- and
- in response to a surface grade where the vehicle is stopped or a launch metric of the vehicle when the vehicle is stopped, rotate a rotor of the electric machine to a predetermined rotational position of the one or more predetermined rotational rotor positions retrieved from memory, wherein the launch metric is a rate of vehicle speed change from zero to a predetermined vehicle speed.
5 more elements
A method for operating a vehicle, comprising:
- retrieving one or more target positions from a controller memory, wherein the one or more target positions comprise rotor positions where maximum output torque is output by the electric machine,
- applying vehicle brakes to hold the vehicle at zero speed,
- opening a dog clutch, wherein the dog clutch includes teeth, and
- rotating an electric machine to a predetermined position in response to determining that the electric machine outputs less than an amount of torque to overcome a road surface grade the vehicle is on while the vehicle speed is zero and that the electric machine is not positioned for the electric machine to generate its maximum torque at zero speed, wherein the predetermined position is closest in angular displacement to one of the one or more target positions retrieved from controller memory subject to a number of the teeth of the dog clutch and an angular orientation of the teeth of the dog clutch.
1 more element
Dependencies are inferred from the claim text.