Method and system for hybrid vehicle control
AssigneeFord Global Technologies, LLC
InventorsThomas G. Leone, Kenneth James Miller, Douglas Raymond Martin
Life of this patent
Estimating the term…
Abstract
Methods and systems are provided for synergizing the benefits of an engine exhaust driven fuel reformer in a hybrid vehicle system. A vehicle controller may hold the engine in a narrow operating range where fuel reformer operation is optimal while using motor and/or CVT adjustments to address transients generated as driver demand varies. The controller may also adjust an operating range of temperatures of the reformer to enable extended fuel reforming even after the engine of the hybrid has been shutdown.
Claims20
A method for a hybrid vehicle, comprising:
- responsive to lower than threshold engine load while an available reformate is lower than a threshold level,
- raising engine load above the threshold load and charging a system battery using excess engine torque;
- and
- reforming a liquid fuel using exhaust energy, the engine operated with the raised load until the available reformate is higher than the threshold level.
A method for a hybrid vehicle, comprising:
- operating an engine with a first fuel while concurrently reforming the first fuel into a gaseous fuel at a reformer driven by engine exhaust energy;
- and
- in response to an engine shutdown request, shutting down the engine while continuing to reform the first fuel until a reformer temperature is below a threshold.
A hybrid vehicle system, comprising:
- an engine including an intake and an exhaust;
- an EGR passage including an EGR valve coupling the exhaust to the intake;
- a first fuel injector for delivering a liquid fuel from a first fuel tank into the engine;
- a second fuel injector for delivering a gaseous fuel from a second fuel tank into the engine;
- an electric motor driven by a battery;
- a continuously variable transmission;
- a reformer coupled to the engine exhaust;
- and
- a controller with computer readable instructions stored on non-transitory memory for:
- operating the reformer to reform at least a portion of the liquid fuel into the gaseous fuel;
- responsive to a first drop in demanded torque while a level of the gaseous fuel in the second tank is higher than a threshold level, transitioning to propelling the vehicle using motor torque at a first engine load;
- and
- responsive to a second drop in demanded torque while a level of the gaseous fuel in the second tank is lower than the threshold level,
- transitioning to propelling the vehicle using motor torque at a second engine load higher than the first load when a state of charge of the battery is higher than a threshold charge;
- and
- when the state of charge of the battery is lower than the threshold charge, raising the engine load to provide higher than demanded torque while using excess torque to charge the battery.
Dependencies are inferred from the claim text.