METHOD AND APPARATUS FOR DEVELOPING A DECELERATION-BASED SYNCHRONOUS SHIFT SCHEDULE

• US 20090118949A1
• Filed: 10/03/2008
• Published: 05/07/2009
• Est. Priority Date: 11/02/2007
• Status: Active Grant

• Current Assignee: Bayerische Motoren Werke AG, Daimler AG (Mercedes-Benz Group AG), Chrysler Group 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., Sah, Jy-Jen F., Kaminsky, Lawrence A., Kim, Kee Yong
• Granted Patent: US 8,825,320 B2
• Time in Patent Office: Days
• US Class Current: 701/55
• CPC Class Codes: B60K 1/02 comprising more than one electric motor
• CPC Class Codes: B60K 6/365 with the gears having orbital motion
• 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 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 30/19 Improvement of gear change, e.g. by synchronisation or smoothing gear shift
• 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 2037/102 the input or output shaft of the transmission is connected or connectable to two or more differentials
• CPC Class Codes: F16H 2037/104 Power split variators with one end of the CVT connected or connectable to two or more differentials
• CPC Class Codes: F16H 2037/106 with switching means to provide two variator modes or ranges
• CPC Class Codes: F16H 2061/022 Calculation or estimation of optimal gear ratio, e.g. best ratio for economy drive or performance according driver preference, or to optimise exhaust emissions
• CPC Class Codes: F16H 61/0213 characterised by the method for generating shift signals
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y02T 10/72 Electric energy management in electromobility

Abstract

A method for controlling a powertrain includes monitoring a desired synchronous transmission shift during deceleration of an output member including a desired operating range state, monitoring an output speed, predicting output deceleration through the desired synchronous transmission shift, determining a penalty cost associated with the desired synchronous transmission shift based upon an input speed profile resulting from the predicted output deceleration and from the desired synchronous transmission shift, and executing the synchronous transmission shift based upon the penalty cost.

Claims

1. Method for controlling a powertrain comprising an electromechanical transmission mechanically-operatively coupled to an internal combustion engine and an electric machine adapted to selectively transmit mechanical power to an output member, the method comprising:

monitoring a desired synchronous transmission shift during deceleration of said output member including a desired operating range state;

monitoring an output speed;

predicting output deceleration through said desired synchronous transmission shift;

determining a penalty cost associated with said desired synchronous transmission shift based upon an input speed profile resulting from said predicted output deceleration and from said desired synchronous transmission shift; and

executing said synchronous transmission shift based upon said penalty cost.

2. The method of claim 1, wherein said determining a penalty cost comprises:

monitoring a current operating range state;

determining an operating range state transition required to change from said current operating range state to said desired operating range state;

predicting a minimum input speed resulting during said desired synchronous transmission shift based upon said predicted output deceleration and said operating range state transition; and

determining a penalty cost associated with said predicted minimum input speed.

3. The method of claim 2, wherein said determining said penalty cost further comprises determining whether said predicted minimum input speed violates a minimum allowed input speed.

4. The method of claim 2, wherein said determining said penalty cost further comprises evaluating drivability impacts of said predicted minimum input speed.

5. The method of claim 2, wherein said determining said penalty cost further comprises evaluating fuel efficiency impacts of said predicted minimum input speed.

6. The method of claim 2, wherein said determining said penalty cost further comprises utilizing a look-up table calibrated according to effects of transitions to said desired operating range state from said current operating range state including operation at said predicted minimum input speed.

7. The method of claim 2, further comprising:

monitoring inputs describing desired powertrain operation;

determining an alternative synchronous transmission shift including an alterative operating range state based upon said inputs;

determining an operating range state transition required to change from said current operating range state to said alternative operating range state;

predicting output deceleration through said alternative synchronous transmission shift;

predicting a minimum input speed resulting during said alternative synchronous transmission shift based upon said predicted output deceleration and said operating range state transition to said alternative operating range state; and

determining a penalty cost associated with said predicted minimum input speed said synchronous transmission shift to said alternative operating range state; and

wherein said executing said synchronous transmission shift comprises selecting between said desired operating range state and said alternative operating range state based upon said penalty costs.

8. The method of claim 1, further comprising:

determining an alternative synchronous transmission shift including an alternative operating range state;

predicting output deceleration through said alternative synchronous transmission shift;

determining a penalty cost associated with said alternative synchronous transmission shift based upon an input speed profile resulting from said predicted output deceleration through said alternative synchronous transmission shift and from said alternative synchronous transmission shift; and

executing said synchronous transmission shift based upon comparing said penalty cost associated with said desired synchronous transmission shift and said penalty cost associated with said alternative synchronous transmission shift.

9. Method for controlling a powertrain comprising an electromechanical transmission mechanically-operatively coupled to an internal combustion engine and first and second electric machines adapted to selectively transmit mechanical power to an output member, the method comprising:

monitoring a current operating range state of said transmission;

monitoring a desired synchronous transmission shift during a deceleration of said output member including a desired operating range state;

monitoring an output speed;

predicting a minimum input speed through said desired synchronous shift based upon said current operating range state, said desired synchronous transmission shift, and said output speed;

determining a penalty cost associated with said desired synchronous transmission shift based upon said predicted minimum input speed; and

executing said synchronous transmission shift based upon said penalty cost.

10. The method of claim 9, wherein said determining said penalty cost comprises determining whether said predicted minimum input speed violates a minimum allowed input speed.

11. The method of claim 9, wherein said predicting said minimum input speed through said desired synchronous shift comprises:

determining a transitory operating range state required to transition from said current operating range state to said desired operating range state;

determining projected output speeds through said deceleration of said output member; and

utilizing said projected output speeds and said transitory operating range state to predict input speeds through said desired synchronous shift.

12. The method of claim 11, wherein said determining said penalty cost comprises evaluating drivability impacts of said predicted minimum input speed.

13. The method of claim 11, wherein said determining said penalty cost comprises evaluating fuel efficiency impacts of said predicted minimum input speed.

14. Method for controlling a powertrain comprising an electromechanical transmission mechanically-operatively coupled to an internal combustion engine and first and second electric machines adapted to selectively transmit mechanical power to an output member, the method comprising:

monitoring a desired synchronous transmission shift during deceleration of said output member including a desired operating range state;

monitoring an output speed;

determining a penalty cost associated with said desired synchronous transmission shift based upon a look-up table calibrated according to projected output speeds through said deceleration of said output member, input speed profiles resulting from said desired transmission shift, and predicted effects of said input speed profiles; and

executing said synchronous transmission shift based upon said penalty cost.

15. Method for controlling a powertrain comprising an electromechanical transmission mechanically-operatively coupled to an internal combustion engine and first and second electric machines adapted to selectively transmit mechanical power to an output member, the method comprising:

monitoring a current operating range state of said transmission;

monitoring a desired powertrain output deceleration;

identifying a plurality of potential destination operating range states possible based upon said desired powertrain output deceleration;

determining input speed profiles associated with each of said potential destination operating range states;

determining a transmission shift penalty cost for each potential destination operating range state based upon said input speed profiles; and

executing a synchronous transmission shift based upon said transmission shift penalty costs.