Method and control architecture for selection of optimal engine input torque for a powertrain system

• US 7,983,823 B2
• Filed: 09/11/2007
• Issued: 07/19/2011
• Est. Priority Date: 09/11/2007
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations LLC (General Motors Company)
• Inventors: Heap, Anthony H.
• Primary Examiner(s): To; Tuan C
• Application Number:
  US11/853,101
• Publication Number:
  US 20090069989A1
• Time in Patent Office: 1,407 Days
• Field of Search: 701/51, 701/22, 180/165, 180/65.265, 180/65.23, 180/65.21, 180/65.28, 477/3, 477/15
• US Class Current: 701/51
• CPC Class Codes: B60K 6/445 Differential gearing distribution type
• 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 20/00 Control systems specially adapted for hybrid vehicles hybrid vehicle design, B60K6/00; electric vehicles B60L
• CPC Class Codes: B60W 20/10 Controlling the power contribution of each of the prime movers to meet required power demand
• CPC Class Codes: B60W 2510/0657 Engine torque
• CPC Class Codes: B60W 30/1882 characterised by the working point of the engine, e.g. by using engine output chart
• CPC Class Codes: Y02T 10/40 Engine management systems
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y02T 10/84 Data processing systems or methods, management, administration

Abstract

A method and article of manufacture are provided for operating an internal combustion engine adapted to transmit torque to a hybrid transmission. The method comprises determining engine input torque transmittable to the hybrid transmission for each of a plurality of engine states. Costs are determined for operating the engine and hybrid transmission in the engine states to substantially meet an operator torque request. A preferred engine state is selected based upon the determined costs. The engine is controlled based upon the preferred engine state to substantially meet an operator torque request.

Claims

1. Method for operating an internal combustion engine adapted to transmit torque to a hybrid transmission, comprising:

determining an engine input torque range transmittable to the hybrid transmission for each respective engine state of a plurality of engine states;

determining costs for operating the engine and hybrid transmission in the determined engine input torque range for each respective engine state to substantially meet an operator torque request, the determined costs based on factors related to vehicle drivability, fuel economy, emissions and battery life;

selecting a preferred engine state and a preferred engine input torque based upon the determined costs; and

,

controlling the engine based upon the preferred engine state and the preferred engine input torque to substantially meet an operator torque request.

2. The method of claim 1, wherein the engine states comprise a normal engine operating state, a cylinder deactivation state, an engine fuel-cutoff state, and, an engine fuel-cutoff state with cylinder deactivation.

3. The method of claim 2, wherein determining costs comprises determining a minimum powertrain system operating cost and an associated engine input torque to substantially meet the operator torque request at the minimum powertrain system operating cost when the engine state comprises one of the normal engine state and the cylinder deactivation state.

4. The method of claim 3, wherein determining costs comprises evaluating operation of the powertrain system to determine an operating cost to substantially meet the operator torque request when the engine state comprises one of the engine fuel cut-off state and the engine fuel cut-off state with cylinder deactivation.

5. The method of claim 1, further comprising determining an engine input torque range transmittable to the hybrid transmission for each respective engine state of the plurality of engine states based upon a current operating range of the hybrid transmission.

6. The method of claim 5, wherein the current operating range of the hybrid transmission comprises one of a plurality of fixed gear modes and two continuously variable modes.

7. The method of claim 1, further comprising controlling the engine to an allowable engine state.

8. The method of claim 1, wherein controlling the engine based upon the preferred engine state and the preferred engine input torque to substantially meet an operator torque request comprises controlling engine input torque to the hybrid transmission.

9. The method of claim 8, further comprising controlling the engine input torque and a desired engine state.

10. The method of claim 1, wherein the engine input torque range transmittable to the hybrid transmission for each respective engine state of the plurality of engine states is determinable based upon the operator torque request, engine operating conditions, and engine operating constraints.

11. Method for operating a powertrain comprising an internal combustion engine and first and second electrical machines and an electro-mechanical transmission selectively operative to transmit torque therebetween and to transmit torque to a driveline, the method comprising:

determining allowable engine states and an operator torque request;

determining an engine input torque range transmittable to the hybrid powertrain system at each respective allowable engine state;

determining powertrain system costs for operating the engine and hybrid transmission in the engine input torque range for each respective allowable engine state to substantially meet the operator torque request, the determined powertrain system costs based on factors related to vehicle drivability, fuel economy, emissions and battery life;

selecting a preferred engine state and a preferred engine input torque based upon the determined powertrain system costs for the allowable engine states; and

,

controlling the engine based upon the preferred engine state and a preferred engine input torque to substantially meet the operator torque request.

12. The method of claim 11, further comprising commanding operation of the engine to the preferred engine state.

13. The method of claim 11, wherein the engine input torque range for each respective engine state is determined based upon an engine input speed to the transmission, a transmission output speed, a current operating range state of the transmission, the operator torque request, and available power from an electrical storage device operatively connected to the first and second electrical machines.