METHOD FOR CONTROLLING A SPEED LEVEL AND TORQUE OF AN ENGINE WITHIN A POWERTRAIN

• US 20090118927A1
• Filed: 09/29/2008
• Published: 05/07/2009
• Est. Priority Date: 11/07/2007
• Status: Active Grant

• Current Assignee: Bayerische Motoren Werke AG, Daimler AG (Mercedes-Benz Group AG), FCA US LLC (Stellantis NV)
• Original Assignee: BMW AG (Bayerische Motoren Werke AG), GM Global Technology Operations Incorporated (General Motors Company), Daimler AG (Mercedes-Benz Group AG), Chrysler LLC (Stellantis NV)
• Inventors: Heap, Anthony H., Wu, Bin, Kim, Kee Yong, Brunssen, Wilfried, McConnell, Jason J., Medema, Brian R.
• Granted Patent: US 8,433,486 B2
• Time in Patent Office: Days
• US Class Current: 701/54
• CPC Class Codes: B60K 6/365 with the gears having orbital motion
• CPC Class Codes: B60W 10/04 including control of propulsion units
• 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 10/105 of electric type
• 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 2540/10 Accelerator pedal position
• CPC Class Codes: B60W 2540/12 Brake pedal position
• CPC Class Codes: B60W 2710/24 Energy storage means
• CPC Class Codes: B60W 30/188 Controlling power parameters of the driveline, e.g. determining the required power
• CPC Class Codes: F16H 2037/106 with switching means to provide two variator modes or ranges
• 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 to determine a preferred operating point for an internal combustion engine includes determining a current set of candidate operating points for a current search iteration. The method further includes iteratively determining an operating cost for operating the internal combustion engine at each candidate operating point of the current search iteration, and determining the preferred operating point for operating the internal combustion engine after a predetermined number of search iterations.

Claims

1. A method to determine a preferred operating point for an internal combustion engine mechanically coupled to an electro-mechanical transmission to transmit power to a driveline in response to an operator torque request, the method comprising:

determining a current set of candidate operating points for a current search iteration;

iteratively

determining an operating cost for operating the internal combustion engine at each candidate operating point of the current search iteration,

determining a candidate operating point for the current search iteration having a lowest operating cost,

determining a search direction relative to the current set of candidate operating points for the current search iteration based on the candidate operating point of the current search iteration having the lowest operating cost,

determining a subsequent set of candidate operating points for a subsequent search iteration based upon the search direction; and

determining the preferred operating point for operating the internal combustion engine comprising the candidate operating point with the lowest operating cost determined after a predetermined number of iterations.

2. The method of claim 1, further comprising:

determining an operator torque request;

defining a search area based upon the operator torque request; and

iteratively determining sets of candidate operating points within the search area.

3. The method of claim 2, further comprising determining a first candidate operating point outside the search area and identifying a second candidate operating point within the search area, wherein the current set of candidate operating points for the current search iteration includes the second candidate operating point.

4. The method of claim 1, wherein determining the current set of candidate operating points for the current search iteration and the subsequent set of candidate operating points for the subsequent search iteration comprises defining rectangles within the search area.

5. The method of claim 1, wherein the current set of candidate operating points for the current search iteration and the subsequent set of candidate operating points for the subsequent search iteration have a common operating point.

6. The method of claim 1, further comprising identifying a base point for the candidate operating points for the current search iteration, and determining the search direction based on the identified base point.

7. The method of claim 5, further comprising selecting the subsequent set of candidate operating points for the subsequent search iteration that define a rectangle having a common side with the rectangle defined by the current set of candidate operating points for the current search iteration when the same candidate operating point is identified as the base point for three consecutive iterations.

8. The method of claim 1, comprising increasing the search resolution during each subsequent search iteration.

9. The method of claim 1, wherein the predetermined number of iterations is nine iterations.

10. The method of claim 1, comprising determining the operating cost for twenty-eight candidate operating points.

11. The method of claim 1, wherein calculating an operating cost comprises calculating an operating cost associated with at least one of vehicle driveability, fuel economy, emissions, and battery usage.

12. The method of claim 1, further comprising:

monitoring an operator torque request; and

calculating an operating cost based on the operator torque request.

13. The method of claim 1, further comprising recording in a storage medium a speed value and a torque value utilized for operating the internal combustion engine.

14. The method of claim 1, wherein determining the current set of candidate operating points of the current search iteration comprises determining four candidate operating points.

15. A method to determine a preferred operating point for an internal combustion engine mechanically coupled to an electro-mechanical transmission to transmit power to a driveline in response to an operator torque request, the method comprising:

defining a search area comprising operating points for the internal combustion engine;

determining a current set of candidate operating points for a current search iteration within the search area;

iteratively

determining an operating cost for operating the internal combustion engine at each candidate operating point of the current search iteration,

determining a candidate operating point for the current search iteration having a lowest operating cost,

determining a search direction relative to the current set of candidate operating points for the current search iteration based on the candidate operating point of the current search iteration having the lowest operating cost,

determining a subsequent set of candidate operating points for a subsequent search iteration based upon the search direction; and

determining the preferred operating point for operating the internal combustion engine comprising the candidate operating point with the lowest operating cost determined after a predetermined number of iterations.

16. The method of claim 15, wherein each candidate operating point comprises an input speed and an input power.

17. The method of claim 15, wherein each candidate operating point comprises an input speed and an input torque.

18. The method of claim 15, wherein calculating an operating cost comprises calculating an operating cost associated with at least one of vehicle driveability, fuel economy, emissions, and battery usage.

19. The method of claim 15, further comprising:

determining an operator torque request; and

defining the search area based upon the operator torque request.

20. The method of claim 15, wherein determining the current set of candidate operating points of the current search iteration comprises determining four candidate operating points.

21. A method to determine a preferred operating point for an internal combustion engine mechanically coupled to an electro-mechanical transmission to transmit power to a driveline, the method comprising:

defining an operating point search range;

normalizing the operating point search range;

determining a current set of candidate operating points for a current search iteration;

iteratively

determining an operating cost for operating the internal combustion engine at each candidate operating point of the current search iteration,

determining a candidate operating point for the current search iteration having a lowest operating cost,

determining a search direction relative to the set of candidate operating points for the current search iteration based on the candidate operating point of the current search iteration having the lowest operating cost,

determining a subsequent set of candidate operating points for a subsequent search iteration based upon the search direction; and

determining the preferred operating point for operating the internal combustion engine comprising the candidate operating point with the lowest operating cost determined after a predetermined number of iterations.