Driveline lash estimation and clunk management using multivariable active driveline damping

• US 20070225888A1
• Filed: 03/22/2006
• Published: 09/27/2007
• Est. Priority Date: 03/22/2006
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations Incorporated (Motors Liquidation Co. GUC Trust)
• Inventors: Morris, Robert
• Granted Patent: US 7,577,507 B2
• Time in Patent Office: Days
• US Class Current: 701/51
• 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: B60K 6/547 the transmission being a stepped gearing
• 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 20/11 using model predictive control [MPC] strategies, i.e. control methods based on models predicting performance utilising navigation and traffic information in the control strategy B60W20/12
• CPC Class Codes: B60W 2555/20 Ambient conditions, e.g. wind or rain
• CPC Class Codes: B60W 30/19 Improvement of gear change, e.g. by synchronisation or smoothing gear shift
• CPC Class Codes: B60W 30/20 Reducing vibrations in the driveline
• 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: Y02T 10/62 Hybrid vehicles

Abstract

Driveline lash and clunk are controlled in a powertrain system having multiple torque-generative and torque control devices using a multivariable feedback control approach to provide active driveline damping. Control parameters used by a state estimator are different, depending on whether the driveline lash is taken up or is currently slack. When the estimated driveline axle torque is not substantially zero, the nominal parameters for transmission mode or gear are used in the state estimator. When the estimated axle torque is substantially zero, the parameters are switched to neutral parameters, the lash estimator indicates neutral lash state, and angle of lash is tracked until it accumulates an expected amount of lash in the driveline. During a lash transition time, active damping controls the driveline component speeds so that the effect of lash take-up is minimized. After lash take-up occurs, desired axle torque is used by the system.

Claims

1. Method for controlling torque transmitted between a powertrain system and a driveline, the powertrain system comprising a plurality of torque-generative devices operably connected to a transmission, comprising:

determining a lash state of the driveline; and

,

controlling the torque-generative devices based upon the lash state.

2. The method of claim 1, wherein determining a lash state comprises:

determining a driveline axle torque;

determining an output speed of the powertrain and an output speed of a driven wheel of the driveline;

determining the lash state to be one of a positive state, a negative state, and a neutral state, based upon the driveline axle torque and the output speeds of the powertrain and the driven wheel of the driveline.

3. The method of claim 2, wherein determining the lash state to be a neutral state based upon the driveline axle torque further comprises determining the lash state to be the neutral state when the driveline axle torque is substantially equal to a nil torque value.

4. The method of claim 3, comprising controlling the torque-generative devices such that a rate of change of torque transmitted between the powertrain system and the driveline is less than an operator-commanded rate of change of driveline torque when the lash state is neutral.

5. The method of claim 3, further comprising controlling the torque-generative devices such that the torque transmitted between the powertrain system and the driveline is less than an operator-commanded torque for a period of time.

6. The method of claim 2, wherein controlling the torque-generative devices based upon the lash state comprises:

selecting a gain matrix for a multivariate feedback control system operable to control each of the torque-generative devices based upon the lash state.

7. The method of claim 6, comprising selecting the gain matrix for the multivariate feedback control system operable to control the plurality of torque-generative devices such that torque transmitted between the powertrain system and the driveline is less than an operator-commanded torque when the lash state is neutral.

8. The method of claim 7, further comprising controlling the torque-generative devices such that the torque transmitted between the powertrain system and the driveline is less than the operator-commanded torque for a period of time.

9. The method of claim 8, wherein monitoring powertrain torque transmitted between the powertrain system and the driveline comprises measuring torque with a sensor.

10. The method of claim 8, wherein monitoring powertrain torque transmitted between the powertrain system and the driveline comprises estimating torque transmitted to the driveline.

11. The method of claim 1, wherein determining an axle torque comprises estimating axle torque based upon the output speeds of the powertrain and the driven wheel.

12. The method of claim 1, wherein determining output speed of the powertrain comprises measuring an output speed of the transmission device operable to transmit torque from each of the torque-generative devices to the driveline.

13. The method of claim 1, wherein determining output speed of the driven wheel comprises measuring wheel speed with a sensor.

14. The method of claim 13, wherein determining output speed of the driven wheel further comprises measuring wheel speeds of a plurality of driven wheels, and determining an average value for wheel speed therefrom.

15. The method of claim 1, wherein determining the output speed of the powertrain and the output speed of the driven wheel of the driveline comprises estimating the output speed of the transmission of the powertrain and the output speed of the driven wheel based upon measured operating parameters.

16. Article of manufacture, comprising a storage medium having a computer program encoded therein for effecting a method to control torque transmitted between a powertrain and a driveline, the powertrain system comprising a plurality of torque-generative devices operably connected to a transmission, the program comprising:

code to determine a lash state of the driveline; and

,

code to control the torque-generative devices based upon the lash state.

17. The article of manufacture of claim 16, wherein the code to determine the lash state further comprises:

code to determine a driveline axle torque;

code to determine an output speed of the powertrain and an output speed of a driven wheel of the driveline;

code to determine the lash state to be one of a positive state, a negative state, and a neutral state, based upon the driveline axle torque and the output speeds of the powertrain and the driven wheel of the driveline.

18. The article of manufacture of claim 16, wherein the plurality of torque-generative devices comprises a first and a second electric machine.

19. The article of manufacture of claim 18, wherein the driveline and the first and second electric machines are operable to transmit torque therebetween by way of the transmission.

20. The article of manufacture of claim 19, wherein the code to control the torque-generative devices based upon the lash state comprises code to control a time-rate transfer of electrical energy between one of the electrical motors and an electrical energy storage device.

21. The article of manufacture of claim 20, wherein the code to control the plurality of torque-generative devices of the powertrain based upon the lash state further comprises code to control torque output from one of the electrical machines.

22. The article of manufacture of claim 20, wherein the code to control the plurality of torque-generative devices of the powertrain based upon the lash state further comprises code to control electrical energy generated by one of the electrical machines.

23. The article of manufacture of claim 18, wherein the plurality of torque-generative devices further comprises an internal combustion engine.

24. Method for controlling a powertrain, the powertrain comprising an electric machine operably connected to a transmission device, comprising:

determining an axle torque of a driveline operably connected to an output of the transmission device;

determining output speeds of the transmission and a driven wheel of the driveline;

commanding the electric machine to transition between a torque-generating operating condition and an electrical-generating operating condition;

determining a lash state; and

,

controlling torque transmitted between the powertrain and the driveline based upon the lash state.

25. The method of claim 24, wherein the powertrain device further comprises an internal combustion engine, and, a second electrical machine, each operably connected to the transmission device.

26. The method of claim 24, wherein controlling torque transmitted between the powertrain and the driveline based upon the lash state further comprises controlling a rate of change of torque transmitted between the powertrain and the driveline based upon the lash state.