Powertrain for a hybrid vehicle with all-wheel drive capability and method for controlling wheel slip

• US 8,062,172 B2
• Filed: 11/04/2009
• Issued: 11/22/2011
• Est. Priority Date: 05/03/2001
• Status: Expired due to Term

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Pototschnik, Stefan Paul, Kozarekar, Shailesh Shrikant, Supina, Joseph Gerald
• Primary Examiner(s): Estremsky; Sherry
• Application Number:
  US12/612,276
• Publication Number:
  US 20100049390A1
• Time in Patent Office: 748 Days
• Field of Search: None
• US Class Current: 477/3
• CPC Class Codes: B60K 1/02 comprising more than one electric motor
• CPC Class Codes: B60K 28/16 responsive to, or preventing, skidding of wheels brake control systems for vehicle drive stability B60T8/1755; arrangements responsive to a speed condition for adjusting wheel braking force B60T8/32; control of vehicle driving stability otherwise than by controlling the propulsion unit only B60W30/02; preventing wheel slippage by reducing power in rail vehicles B61C15/00
• CPC Class Codes: B60K 6/365 with the gears having orbital motion
• CPC Class Codes: B60K 6/40 characterised by the assembly or relative disposition of components
• CPC Class Codes: B60K 6/445 Differential gearing distribution type
• CPC Class Codes: B60K 6/448 Electrical distribution type
• CPC Class Codes: B60K 6/52 Driving a plurality of drive axles, e.g. four-wheel drive
• CPC Class Codes: B60K 6/54 Transmission for changing ratio
• CPC Class Codes: B60K 6/547 the transmission being a stepped gearing
• CPC Class Codes: B60W 10/02 including control of driveline clutches
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 10/10 including control of change-speed gearings
• CPC Class Codes: B60W 10/115 with planetary gears
• CPC Class Codes: B60W 20/00 Control systems specially adapted for hybrid vehicles hybrid vehicle design, B60K6/00; electric vehicles B60L
• CPC Class Codes: B60W 20/30 Control strategies involving selection of transmission gear ratio control of change speed gearings, together with other vehicle sub-units B60W10/10; HEV transmission gearing B60K6/36; gearings and control thereof F16H
• CPC Class Codes: B60W 2520/26 Wheel slip
• CPC Class Codes: B60W 2720/403 between front and rear axle
• CPC Class Codes: B60W 30/18027 Drive off, accelerating from standstill
• CPC Class Codes: F16H 2037/0866 Power split variators with distributing differentials, with the output of the CVT connected or connectable to the output shaft
• CPC Class Codes: F16H 2037/0873 : with switching, e.g. to change ranges
• CPC Class Codes: F16H 2200/0034 : the gear ratios comprising two forward speeds
• CPC Class Codes: F16H 2200/2005 : with one sets of orbital gears
• CPC Class Codes: F16H 2200/2007 : with two sets of orbital gears
• CPC Class Codes: F16H 2200/2035 : with two engaging means
• CPC Class Codes: F16H 3/52 : comprising orbital spur gears
• CPC Class Codes: F16H 3/54 : one of the central gears being internally toothed and the other externally toothed
• CPC Class Codes: F16H 3/725 : with means to change ratio in the mechanical gearing
• CPC Class Codes: F16H 3/727 : with at least two dynamo electric machines for creating an electric power path inside the gearing, e.g. using generator and motor for a variable power torque path special adapted for a hybrid electric vehicle B60K6/20
• CPC Class Codes: F16H 3/728 : with means to change ratio in the mechanical gearing
• CPC Class Codes: F16H 37/046 : with an additional planetary gear train, e.g. creep gear, overdrive
• CPC Class Codes: F16H 57/04 : Features relating to lubrication or cooling or heatingin hydrokinetic gearing F16H41/30; control of lubrication or cooling in hydrostatic gearing F16H61/4165
• CPC Class Codes: F16H 57/0434 : relating to lubrication supply, e.g. pumps arrangement of pumps F16H57/0441; Pressure control grooves with pumping effect for supplying lubricant F16H57/0428; generation and variation of line pressure for transmission control F16H61/0021
• CPC Class Codes: Y02T 10/62 : Hybrid vehicles
• CPC Class Codes: Y10S 903/916 : with plurality of drive axles

Abstract

A hybrid-electric powertrain and control method for a vehicle having forward traction wheels and rearward traction wheels in an all-wheel drive configuration. An engine and an electric motor deliver power through delivery paths to the traction wheels. The power delivery paths may have multiple ratio gearing so that more power can be delivered mechanically to improve powertrain performance and to allow the electric motor size to be reduced. The powertrain includes a controller for automatically balancing power distribution to the forward and rearward traction wheels to avoid wheel slip.

Claims

1. A method for controlling power distribution to front traction wheels and to rear traction wheels in a hybrid-electric powertrain for an all-wheel drive vehicle, the powertrain comprising an engine, a generator, an electric motor and a geared transmission establishing power distribution to the traction wheels, the method comprising:

determining whether an all-wheel drive mode is on;

determining power demand;

conditioning the powertrain for negative power distribution when the all-wheel drive mode is off and power demand is low; and

conditioning the powertrain for positive power distribution when the all-wheel drive mode is off and power demand is high.

2. A method for controlling power distribution to front traction wheels and to rear traction wheels in a hybrid-electric powertrain for an all-wheel drive vehicle, comprising:

detecting whether an all-wheel drive mode is on;

conditioning the powertrain for positive power distribution when the all-wheel drive mode is on; and

determining engine torque using a calibrated driver demand and engine speed relationship.

3. A method for managing proportional power distribution to front fraction wheels and to rear fraction wheels in a hybrid-electric powertrain for an all-wheel drive vehicle, the method comprising:

determining whether an all-wheel drive mode is selected;

measuring wheel speeds at the fraction wheels;

obtaining one set of engine speed and torque values for the engine when the all-wheel drive mode is selected;

obtaining another set of engine speed and torque values for the engine when a two-wheel drive mode is selected;

the sets of engine speed and torque values defining operating modes for the engine characterized by selected engine performance and efficiency for all-wheel drive operation and for two-wheel drive operation;

detecting rear wheel slip; and

decreasing engine torque and increasing motor torque when the rear wheels slip, whereby total wheel torque at the wheels remains unchanged.

4. A method for managing proportional power distribution to front fraction wheels and to rear fraction wheels in a hybrid-electric powertrain for an all-wheel drive vehicle, the method comprising:

determining whether an all-wheel drive mode is selected;

measuring wheel speeds at the traction wheels;

obtaining one set of engine speed and torque values for the engine when the all-wheel drive mode is selected;

obtaining another set of engine speed and torque values for the engine when a two-wheel drive mode is selected;

the sets of engine speed and torque values defining operating modes for the engine characterized by selected engine performance and efficiency for all-wheel drive operation and for two-wheel drive operation;

detecting front wheel slip; and

increasing engine torque and decreasing motor torque when the front wheels slip, whereby total torque at the wheels remains unchanged.