Electric launch of a hybrid vehicle having a belt alternator starter and a dual clutch transmission
First Claim
1. A method for providing an electric-only (EV) launch mode in a vehicle having an accelerator pedal, an engine having a crankshaft, a motor generator unit (MGU), a dual-clutch transmission (DCT) with an odd-gear clutch and an even-gear clutch, wherein the vehicle is adapted for selectively rotating the crankshaft using motor torque from the MGU, the method comprising:
- using motor torque from the MGU, while the engine is off, to increase a rotational speed of the crankshaft to above a calibrated minimum EV launch speed when a threshold minimum force is applied to the accelerator pedal;
minimizing engine compression via a controller while increasing the rotational speed of the crankshaft;
controlling an operation of a designated clutch of the odd-gear clutch and the even-gear clutch according to a predetermined torque function until input torque to the DCT equals or exceeds a calibrated level;
slipping the odd-gear clutch or the even-gear clutch that is not designated, while increasing the rotational speed of the crankshaft, in order to dampen drivetrain oscillations; and
launching the vehicle in the EV launch mode via the designated clutch when an input speed to the DCT exceeds a function of engine speed.
4 Assignments
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Accused Products
Abstract
A controller-executable method provides an electric-only (EV) launch mode in a vehicle having an accelerator pedal, an engine, a motor generator unit (MGU), a dual-clutch transmission (DCT), and a belt alternator starter system adapted for selectively rotating the crankshaft using motor torque from the MGU. Execution of the method uses motor torque from the MGU, while the engine is off, to accelerate the crankshaft to above a calibrated launch speed when a threshold minimum force is applied to the pedal. A designated one of the odd- and even-gear clutches of the DCT are controlled until input torque to the DCT equals a calibrated level. The other DCT clutch may be modulated to dampen drivetrain oscillations. The vehicle launches in the EV launch mode via the designated DCT clutch when the crankshaft speed exceeds an input speed of the DCT. The vehicle and controller are also provided.
19 Citations
19 Claims
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1. A method for providing an electric-only (EV) launch mode in a vehicle having an accelerator pedal, an engine having a crankshaft, a motor generator unit (MGU), a dual-clutch transmission (DCT) with an odd-gear clutch and an even-gear clutch, wherein the vehicle is adapted for selectively rotating the crankshaft using motor torque from the MGU, the method comprising:
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using motor torque from the MGU, while the engine is off, to increase a rotational speed of the crankshaft to above a calibrated minimum EV launch speed when a threshold minimum force is applied to the accelerator pedal; minimizing engine compression via a controller while increasing the rotational speed of the crankshaft; controlling an operation of a designated clutch of the odd-gear clutch and the even-gear clutch according to a predetermined torque function until input torque to the DCT equals or exceeds a calibrated level; slipping the odd-gear clutch or the even-gear clutch that is not designated, while increasing the rotational speed of the crankshaft, in order to dampen drivetrain oscillations; and launching the vehicle in the EV launch mode via the designated clutch when an input speed to the DCT exceeds a function of engine speed. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A vehicle comprising:
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an accelerator pedal; an engine having a crankshaft; a motor generator unit (MGU) connectable to the crankshaft, and adapted for selectively generating a motor torque; a dual-clutch transmission (DCT) with an odd-gear input clutch and an even-gear input clutch; and a controller adapted for launching the vehicle in an electric-only (EV) launch mode; wherein the controller is adapted to; use the motor torque from the MGU, while the engine is off, to increase a rotational speed of the crankshaft to above a calibrated minimum EV launch speed when a threshold minimum force is applied to the accelerator pedal; minimize engine compression while increasing the rotational speed of the crankshaft; apply a designated one of the odd-gear clutch and the even-gear clutch according to a predetermined torque function until input torque to the DCT equals or exceeds a calibrated level; slip the other of the odd-gear clutch and the even-gear clutch, while increasing the rotational speed of the crankshaft, to dampen drivetrain oscillations; and launch the vehicle in the EV launch mode via the odd-gear clutch when the rotational speed of the crankshaft exceeds an input speed of the DCT. - View Dependent Claims (9, 10, 11, 12, 13)
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14. A controller adapted for use with a vehicle having an accelerator pedal, an engine having a crankshaft, a motor generator unit (MGU) connectable to the crankshaft and adapted for generating a motor torque, and a dual-clutch transmission (DCT) with an odd-gear clutch and an even-gear clutch, the controller comprising:
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a hardware module; and an algorithm recorded in memory and executable by the hardware module, and for launching the vehicle in an electric-only (EV) launch mode; wherein the controller is adapted for configured to; use the motor torque from the MGU, while the engine is off, to increase a rotational speed of the crankshaft to above a calibrated minimum EV launch speed when a threshold minimum force is applied to the accelerator pedal; minimize engine compression while increasing the rotational speed of the crankshaft; control an operation of a designated one of the odd-gear clutch and the even-gear clutch until input torque to the DCT equals a calibrated level; slip the other of the odd-gear clutch and the even-gear clutch, while increasing the rotational speed of the crankshaft, to dampen drivetrain oscillations; and launch the vehicle in the EV launch mode via the designated clutch when an input speed to the DCT exceeds a function of engine speed. - View Dependent Claims (15, 16, 17, 18, 19)
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Specification