Techniques for controlling engine speed based on alternator duty cycle to increase vehicle efficiency
AssigneeFca US LLC
InventorSongping Yu
Life of this patent
Estimating the term…
Abstract
Techniques for controlling engine speed based on alternator duty cycle to increase overall vehicle efficiency involve increasing engine speed only after the alternator duty cycle exceeds a duty cycle threshold that is less than the maximum duty cycle of the alternator. In this manner, quantity and/or degree of engine speed increases are decreased, which increases vehicle efficiency (e.g., increased fuel economy). Moreover, by utilizing a duty cycle threshold that is less than the maximum alternator duty cycle threshold, voltage drops at an electrical system are avoided. These techniques are also applicable to both conventional alternators and smart alternators having on-board diagnostic circuitry.
Claims16
A system for controlling a speed of an engine of a vehicle, the system comprising:
- an alternator configured to convert mechanical energy generated by the engine into electrical energy for powering an electrical system of the vehicle;
- and
- a controller configured to:
- determine the engine speed;
- obtain a duty cycle of the alternator;
- when the alternator duty cycle exceeds a duty cycle threshold, obtain an engine speed increase that will cause the alternator duty cycle to decrease below the duty cycle threshold, wherein the duty cycle threshold is less than a maximum duty cycle of the alternator;
- determine a first target engine speed by summing the determined engine speed and the engine speed increase corresponding to alternator load;
- determine a second target engine speed that will compensate for other non-alternator loads;
- determine a maximum of the first and second target engine speeds to obtain a modified target engine speed;
- and
- control the engine based on the modified target engine speed.
A method for controlling a speed of an engine of a vehicle, the method comprising:
- determining, by a controller of the engine, the engine speed;
- obtaining, by the controller, a duty cycle of an alternator of the vehicle, the alternator being configured to convert mechanical energy generated by the engine into electrical energy for powering an electrical system of the vehicle;
- when the alternator duty cycle exceeds a duty cycle threshold, obtaining, by the controller, an engine speed increase that will cause the alternator duty cycle to decrease below the duty cycle threshold, wherein the duty cycle threshold is less than a maximum duty cycle of the alternator;
- determining, by the controller, a first target engine speed by summing the determined engine speed and the engine speed increase corresponding to alternator load;
- determining, by the controller, a second target engine speed that will compensate for other non-alternator loads;
- determining, by the controller, a maximum of the first and second target engine speeds to obtain a modified target engine speed;
- and
- controlling, by the controller, the engine based on the modified target engine speed.
Dependencies are inferred from the claim text.