System and method for boosting torque output of a drive train

• US 7,276,806 B1
• Filed: 02/07/2007
• Issued: 10/02/2007
• Est. Priority Date: 09/08/2006
• Status: Expired due to Fees

• Current Assignee: Deere & Company
• Original Assignee: Deere & Company
• Inventors: Gilmore, Brian Joseph, DePoorter, Mark Charles, Finamore, Peter, Teijido, Joseph Albert, Sheidler, Alan David, Ziegler, Duane Herbert
• Primary Examiner(s): Schuberg; Darren
• Assistant Examiner(s): MOHANDESI, IRAJ A
• Application Number:
  US11/672,374
• Time in Patent Office: 237 Days
• Field of Search: 290/40.A, 290/40.B, 290/40.C, 322/28, 322/25, 322/11, 322/13
• US Class Current: 290/40.00A
• CPC Class Codes: B60K 6/48 Parallel type
• CPC Class Codes: B60W 10/04 including control of propulsion units
• 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 20/15 Control strategies specially adapted for achieving a particular effect
• CPC Class Codes: B60W 20/19 for achieving enhanced acceleration
• CPC Class Codes: B60W 2510/0638 Engine speed
• CPC Class Codes: B60W 2510/0657 Engine torque
• CPC Class Codes: B60W 2510/244 Charge state
• CPC Class Codes: B60W 2710/08 Electric propulsion units
• CPC Class Codes: F02D 2200/1002 Output torque
• CPC Class Codes: F02D 2250/24 by using an external load, e.g. a generator
• CPC Class Codes: F02D 29/06 peculiar to engines driving electric generators
• CPC Class Codes: F02D 31/001 Electric control of rotation speed
• CPC Class Codes: F02D 41/0205 using an auxiliary engine speed control engine speed control per se F02D31/00
• CPC Class Codes: F02D 41/021 Introducing corrections for particular conditions exterior to the engine conjoint control of vehicle sub-units for propelling the vehicle B60W30/18
• CPC Class Codes: F02D 41/1497 With detection of the mechanical response of the engine
• CPC Class Codes: F02N 11/04 the motors being associated with current generators
• CPC Class Codes: Y02T 10/62 Hybrid vehicles

Abstract

An engine speed detector detects an engine speed of an engine having a baseline torque versus engine speed curve. A torque sensor detects an engine torque of the engine. A data processor determines if the detected engine speed is within a first speed range and if the detected engine torque is within a first torque range. A motor controller activates an electric motor to rotate substantially synchronously with a corresponding engine speed associated with the detected engine torque in an electric propulsion mode in accordance with a supplemental torque versus engine speed curve if the detected engine speed is within the first speed range and if the detected engine torque is within the first torque range. The supplemental torque versus engine speed curve intercepts the baseline torque versus engine speed curve at a lower speed point and a higher speed point.

Claims

1. A method for boosting a torque output of a drive train, the method comprising:

detecting an engine speed and engine torque of an engine having a baseline torque versus engine speed curve;

determining if the detected engine speed is within a first speed range and if the detected engine torque is within a first torque range; and

activating an electric motor to rotate substantially synchronously with the engine speed within the first range in an electric propulsion mode in accordance with a supplemental torque versus engine speed curve if the detected engine speed is within the first speed range and if the detected engine torque is within the first torque range, the supplemental torque versus engine speed curve intercepting the baseline torque versus engine speed curve at a first lower speed point and a first higher speed point.

2. The method according to claim 1 further comprising:

permitting a transition between the baseline torque versus engine speed curve and the supplemental torque versus engine speed curve only at the first lower speed point and the first higher speed point.

3. The method according to claim 1 wherein the supplemental torque versus engine speed curve is generally parabolic and has an enhanced peak torque between the first lower speed point and the first higher speed point.

4. The method according to claim 1 wherein the enhanced peak torque exceeds the baseline torque at any engine speed.

5. The method according to claim 1 further comprising:

determining if a state of charge of an energy storage device indicates that the energy storage device requires recharging; and

deactivating the electric motor for a time period if the stage of charge indicates that the energy storage device requires recharging.

6. The method according to claim 1 further comprising:

determining if a state of charge of an energy storage device indicates that the energy storage device requires recharging; and

placing the electric motor in a power generation mode for a time period, rather than the electric propulsion mode.

7. The method according to claim 1 further comprising:

determining if the detected engine speed is within a second speed range and if the detected torque is within a second torque range; and

activating an electric motor to rotate substantially synchronously with the engine speed within the second speed range in an electric propulsion mode in accordance with a second supplemental torque versus engine speed curve if the detected engine speed is within the second speed range and if the detected torque is within the second torque range, the second supplemental torque versus engine speed curve intercepting the baseline torque versus engine speed curve at a second lower speed point and a second higher speed point, distinct from the first lower speed point and the second higher speed point.

8. The method according to claim 7 further comprising:

permitting a transition between the baseline torque versus engine speed curve and the second supplemental torque versus engine speed curve only at the second lower speed point and the second higher speed point.

9. The method according to claim 1 wherein the detecting of the engine torque comprises detecting the engine torque during deactivating of the electric motor.

10. The method according to claim 1 wherein the detecting of the engine torque comprises detecting the engine torque while the electric motor is in an active state and deducting a torque contribution of the electric motor from an aggregate torque based on the baseline torque versus engine speed curve and the supplemental torque versus engine speed curve at an applicable operating point.