Deceleration control in a hybrid vehicle
AssigneeToyota Motor Engineering & Manufacturing North America, Inc.
InventorThomas S. Hawley
Life of this patent
Estimating the term…
Abstract
Systems and methods provide power to augment that of an electric motor in a hybrid electric vehicle to control deceleration of the hybrid electric vehicle. When a hybrid electric vehicle is going to encounter some road condition that may require deceleration, e.g., a downgrade, the hybrid electric vehicle may turn off the engine to take advantage of the regenerative braking properties of the hybrid electric vehicle while traversing the downgrade. However, in situations where the electric motor is unable to provide sufficient negative motor torque to control deceleration, the engine can be connected to the drivetrain in a fuel-cut off mode allowing the engine to generate negative engine torque that can augment the negative motor torque.
Claims20
A method comprising:
- determining a vehicle is approaching a road condition that will require the vehicle to decelerate;
- determining an amount of negative torque needed to meet a desired rate of deceleration;
- determining if, based upon the desired rate of deceleration, negative motor torque generated by a motor of the vehicle should be augmented with negative engine torque generated by an engine of the vehicle;
- and
- operating the engine of the vehicle in a fuel-cut off mode to generate the negative engine torque upon a determination that the negative motor torque should be augmented with the negative engine torque.
A hybrid electric vehicle, comprising:
- an internal combustion engine;
- an electric motor operatively connected in parallel to the internal combustion engine;
- and
- an electronic control unit adapted to control operation of the internal combustion engine to augment negative motor torque generated by the electric motor while the hybrid electric vehicle is traveling a portion of roadway having at least one of a downgrade and a turn upon determining that the amount of negative motor torque generated by the electric motor is insufficient to meet a desired rate of deceleration.
Dependencies are inferred from the claim text.