Method and apparatus to create a pseudo torque phase during oncoming clutch engagement to prevent clutch slip for a hybrid powertrain system

• US 8,282,526 B2
• Filed: 10/13/2008
• Issued: 10/09/2012
• Est. Priority Date: 10/29/2007
• Status: Active Grant

• Current Assignee: Bayerische Motoren Werke AG, Daimler AG (Mercedes-Benz Group AG), Chrysler Group LLC (Stellantis NV)
• Original Assignee: Bayerische Motoren Werke AG, GM Global Technology Operations LLC (General Motors Company), Daimler AG (Mercedes-Benz Group AG), Chrysler Group LLC (Stellantis NV)
• Inventors: Heap, Anthony H., Kaminsky, Lawrence A., Sah, Jy-Jen F.
• Primary Examiner(s): Young, Edwin A
• Application Number:
  US12/250,520
• Publication Number:
  US 20090111645A1
• Time in Patent Office: 1,457 Days
• Field of Search: 477/5, 477/77, 477/83, 477/180, 477/181
• US Class Current: 477/5
• 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: B60L 2240/423 Torque
• CPC Class Codes: B60L 2240/443 Torque
• CPC Class Codes: B60L 2240/525 Temperature of converter or components thereof
• CPC Class Codes: B60L 2240/80 Time limits
• CPC Class Codes: B60L 50/16 with provision for separate direct mechanical propulsion
• CPC Class Codes: B60L 50/51 characterised by AC-motors
• CPC Class Codes: B60L 50/61 by batteries charged by engine-driven generators, e.g. series hybrid electric vehicles
• CPC Class Codes: B60W 10/02 including control of driveline clutches
• 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 20/10 Controlling the power contribution of each of the prime movers to meet required power demand
• CPC Class Codes: B60W 2050/0031 Mathematical model of the vehicle
• CPC Class Codes: B60W 2050/0042 Transfer function lag; delays
• CPC Class Codes: B60W 2510/02 Clutches
• CPC Class Codes: B60W 2510/0208 : Clutch engagement state, e.g. engaged or disengaged
• CPC Class Codes: B60W 2510/0241 : Clutch slip, i.e. difference between input and output speeds
• CPC Class Codes: B60W 2510/0266 : Moment of inertia
• CPC Class Codes: B60W 2510/0657 : Engine torque
• CPC Class Codes: B60W 2510/083 : Torque
• CPC Class Codes: B60W 2540/10 : Accelerator pedal position
• CPC Class Codes: B60W 2540/12 : Brake pedal position
• CPC Class Codes: B60W 2710/023 : Clutch engagement rate
• CPC Class Codes: B60W 2710/027 : Clutch torque
• CPC Class Codes: B60W 50/0097 : Predicting future conditions
• 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 3/727 : with at least two dynamo electric machines for creating an electric power path inside the gearing, e.g. using generator and motor for a variable power torque path special adapted for a hybrid electric vehicle B60K6/20
• CPC Class Codes: F16H 3/728 : with means to change ratio in the mechanical gearing
• CPC Class Codes: F16H 61/0403 : Synchronisation before shifting
• CPC Class Codes: Y02T 10/40 : Engine management systems
• CPC Class Codes: Y02T 10/62 : Hybrid vehicles
• CPC Class Codes: Y02T 10/64 : Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/70 : Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 : Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors

Abstract

A method for controlling a powertrain comprising an electro-mechanical transmission mechanically-operatively coupled to an engine and an electric machine adapted to selectively transmit mechanical power to an output member through selective application of a plurality of torque-transfer clutches includes monitoring a clutch slip speed, synchronizing an oncoming clutch, and constraining reactive clutch torque limits for the oncoming clutch to achieve a reactive clutch torque that is less than an estimated clutch torque capacity.

Claims

1. Method for controlling a powertrain comprising an electro-mechanical transmission mechanically-operatively coupled to an internal combustion engine and an electric machine adapted to selectively transmit mechanical power to an output member through selective application of a plurality of torque-transfer clutches, the method comprising:

monitoring a clutch slip speed;

synchronizing an oncoming clutch; and

constraining reactive clutch torque limits for said oncoming clutch to achieve a reactive clutch torque that is less than an estimated clutch torque capacity.

2. The method of claim 1, wherein constraining reactive clutch torque limits comprises:

imposing a clutch reactive torque immediate maximum upon an electric machine torque command, wherein said imposing said clutch reactive torque immediate maximum maintaining said electric machine torque command less than said estimated clutch capacity; and

imposing a clutch reactive torque lead immediate maximum upon an engine torque command, wherein said imposing said clutch reactive torque lead immediate maximum is based upon effecting substantially same said reactive torque limits as said imposing said clutch reactive torque immediate maximum.

3. The method of claim 2, wherein imposing said clutch reactive torque immediate maximum upon an electric machine torque command comprises:

imposing upon said electric machine torque command an immediate delay and a calibrated ramp rate, wherein said immediate delay and said calibrated ramp rate are calculated to effect said maintaining said electric machine torque command less than said estimated clutch capacity;

wherein said imposing said clutch reactive torque immediate maximum upon an electric machine torque command comprises

imposing upon said electric machine torque command a lead immediate delay and said calibrated ramp rate, wherein said lead immediate delay is calculated based upon an estimated engine command reaction time and an estimated electric machine command reaction time and creates said effecting substantially same said reactive torque limits as said imposing said clutch reactive torque immediate maximum.

4. The method of claim 1, wherein constraining reactive clutch torque limits for the oncoming clutch comprises:

calculating said estimated clutch torque capacity;

projecting a clutch torque capacity curve based upon said estimated clutch torque capacity; and

effecting said constraining reactive clutch torque limits based upon said projecting and based upon an estimated engine command reaction time and an estimated electric machine command reaction time.

5. Method for controlling through a transitional locking event a powertrain comprising an electro-mechanical transmission comprising a selectively activated torque-transfer clutch 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 clutch slip speed through a clutch synchronizing event;

diagnosing a locked clutch state based upon said monitoring;

upon said diagnosing said locked clutch state, increasing a clutch torque capacity;

upon running a calibrated lead immediate delay after said diagnosing said locked clutch state, increasing a clutch reactive torque lead immediate maximum command at a controlled ramp rate; and

upon running a calibrated immediate delay after said diagnosing said locked clutch state, increasing a clutch reactive torque immediate maximum command at said controlled ramp rate;

wherein said increasing said clutch reactive torque lead immediate maximum command and said increasing said clutch reactive torque immediate maximum command effect a reactive torque lower than said increasing clutch torque capacity throughout said transitional locking event.

6. The method of claim 5, wherein running said calibrated immediate delay and said increasing said clutch reactive torque immediate maximum command at said controlled ramp rate effect said clutch reactive torque immediate maximum command closely lagging said increasing clutch torque capacity.

7. The method of claim 6, wherein running said calibrated lead immediate delay effects said clutch reactive torque lead immediate maximum command such that an input torque from said engine initially increases substantially coincidentally with an input torque from said electric machine.

8. The method of claim 5, further comprising:

estimating said clutch torque capacity;

projecting a clutch torque capacity curve for the remainder of said transitional locking event; and

modulating said controlled ramp rate based upon said estimating.