Granted Patent B2

US 8,092,339 · App. 12/250,530 · Granted Jan 10, 2012

Abstract

Claims (23)

1. A method for controlling a powertrain in a neutral operating range state 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:

operating said transmission in said neutral operating range state;

monitoring commands affecting an input speed;

monitoring a tracked clutch slip speed;

determining constraints on an input acceleration based upon said commands;

determining a clutch slip acceleration profile based upon said constraints on said input acceleration;

determining an input acceleration profile based upon said clutch slip acceleration profile; and

controlling said powertrain based upon said clutch slip acceleration profile and said input acceleration profile.

2. The method of claim 1 ,

wherein said clutch slip acceleration profile includes a lead signal and an immediate signal, and

wherein said immediate signal is delayed from said lead signal by a lead period calibrated to different reaction times in powertrain torque-generative devices.

3. The method of claim 1 , further comprising determining constraints on a clutch slip acceleration based upon said constraints on said input acceleration; and wherein said determining said clutch slip acceleration profile is based upon said constraints on said clutch slip acceleration.

4. The method of claim 1 , wherein monitoring commands affecting said input speed comprises:

monitoring a desired input speed; and

determining a change in said desired input speed.

5. The method of claim 1 , further comprising monitoring a tracked clutch target slip speed, wherein said determining said clutch slip acceleration profile is further based upon said tracked clutch target slip speed.

6. The method of claim 5 ,

wherein said determining said clutch slip acceleration profile is performed in a first clutch domain, and

wherein controlling said powertrain based upon said clutch slip acceleration profile includes transforming said clutch slip acceleration profile performed in said first clutch domain into a clutch clip acceleration profile performed in a tracked clutch domain.

7. The method of claim 6 , wherein said clutch slip acceleration profile performed in a first clutch domain is based upon calculations determined in said tracked clutch domain and subsequently transformed into said first clutch domain.

8. The method of claim 1 , wherein determining constraints on said input acceleration includes use of hysteresis thresholds to determine ranges of allowable input acceleration values based upon said hysteresis thresholds.

9. The method of claim 8 , wherein use of said hysteresis thresholds includes use of multiple boundary thresholds.

10. The method of claim 8 , wherein use of said hysteresis thresholds includes use of two boundary thresholds for each direction of change to said commands affecting said input speed.

Assignments (19)