METHOD FOR MODEL BASED CLUTCH CONTROL AND TORQUE ESTIMATION

• US 20090105039A1
• Filed: 10/14/2008
• Published: 04/23/2009
• Est. Priority Date: 10/23/2007
• Status: Active Grant

• Current Assignee: Bayerische Motoren Werke AG, Daimler AG (Mercedes-Benz Group AG), Chrysler Group LLC (Stellantis NV)
• Original Assignee: GM Global Technology Operations Incorporated (Motors Liquidation Co. GUC Trust)
• Inventors: Snyder, Bryan R., Naqvi, Ali K., Sah, Jy-Jen F.
• Granted Patent: US 9,140,337 B2
• Time in Patent Office: Days
• 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 2240/441 Speed
• CPC Class Codes: B60L 2240/443 Torque
• CPC Class Codes: B60L 2240/445 Temperature
• CPC Class Codes: B60L 2240/485 Temperature
• 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 10/30 including control of auxiliary equipment, e.g. air-conditioning compressors or oil pumps
• 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 20/40 Controlling the engagement or disengagement of prime movers, e.g. for transition between prime movers power-up or power-down of the driveline B60W30/192
• CPC Class Codes: B60W 2050/0006 Digital architecture hierarchy
• CPC Class Codes: B60W 2510/0638 Engine speed
• CPC Class Codes: B60W 2510/0657 Engine torque
• CPC Class Codes: B60W 2510/0671 Engine manifold pressure
• CPC Class Codes: B60W 2510/0676 : Engine temperature
• CPC Class Codes: B60W 2510/107 : Temperature
• CPC Class Codes: B60W 2510/244 : Charge state
• CPC Class Codes: B60W 2510/246 : Temperature
• CPC Class Codes: B60W 2540/10 : Accelerator pedal position
• CPC Class Codes: B60W 2540/12 : Brake pedal position
• CPC Class Codes: B60W 2555/20 : Ambient conditions, e.g. wind or rain
• CPC Class Codes: B60W 2710/0605 : Throttle position
• CPC Class Codes: B60W 2710/0616 : Position of fuel or air injector
• CPC Class Codes: B60W 2710/0666 : Engine torque
• CPC Class Codes: B60W 2710/083 : Torque
• CPC Class Codes: F16D 2048/0281 : Complex circuits with more than two valves in series or special arrangements thereof not provided for in previous groups
• CPC Class Codes: F16D 2048/0287 : Hydraulic circuits combining clutch actuation and other hydraulic systems
• CPC Class Codes: F16D 2500/1024 : combined with hydraulic actuation
• CPC Class Codes: F16D 2500/3024 : Pressure
• CPC Class Codes: F16D 2500/3166 : Detection of an elapsed period of time
• CPC Class Codes: F16D 2500/50251 : During operation
• CPC Class Codes: F16D 2500/70424 : Outputting a clutch engaged-disengaged signal
• CPC Class Codes: F16D 48/066 : Control of fluid pressure, e.g. using an accumulator F16D48/062, F16D48/068 take precedence
• 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 2061/062 : for controlling filling of clutches or brake servos, e.g. fill time, fill level or pressure during filling
• CPC Class Codes: F16H 3/728 : with means to change ratio in the mechanical gearing
• CPC Class Codes: F16H 61/061 : using electric control means
• CPC Class Codes: Y02T 10/62 : Hybrid vehicles
• CPC Class Codes: Y02T 10/64 : Electric machine technologies in electromobility

Abstract

A method for operating a powertrain through selective application of a hydraulically actuated clutch includes monitoring a state of a pressure control switch operatively coupled the clutch, monitoring a hydraulic line pressure utilized by the pressure control switch to fill the clutch, determining a hydraulic flow rate flowing to the clutch based upon the state of the pressure control switch and the hydraulic line pressure, tracking a clutch fill volume of the clutch based upon the hydraulic flow rate, and controlling operation of the clutch based upon the clutch fill volume.

Claims

1. Method for operating 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 hydraulically actuated clutches, the method comprising:

monitoring a state of a pressure control switch operatively coupled to a clutch;

monitoring a hydraulic line pressure utilized by said pressure control switch to fill said clutch;

determining a hydraulic flow rate flowing to said clutch based upon said state of said pressure control switch and said hydraulic line pressure;

tracking a clutch fill volume of said clutch based upon said hydraulic flow rate; and

controlling operation of said clutch based upon said clutch fill volume.

2. The method of claim 1, wherein controlling operation of said clutch comprises:

estimating a clutch fill completion time; and

indicating a clutch fill completion indicating said clutch is in a touching state.

3. The method of claim 2, wherein indicating said clutch fill completion comprises:

estimating a time span wherein achieving clutch fill completion is expected based upon said clutch fill volume and said hydraulic flow rate;

monitoring an output of a pressure switch operatively coupled to said clutch and indicating achievement of a clutch pressure calibrated to expected clutch fill completion;

comparing said time span wherein achieving clutch fill completion is expected and said output of said pressure switch; and

indicating said clutch fill completion based upon said comparing.

4. The method of claim 3, wherein indicating said clutch fill completion based upon said comparing comprises:

if said monitoring said output of said pressure switch indicates said achievement of said calibrated clutch pressure before said time span, indicating said clutch fill completion at a beginning of said time span;

if said monitoring said output of said pressure switch indicates said achievement of said calibrated clutch pressure after said time span, indicating said clutch fill completion at an end of said time span;

if said monitoring said output of said pressure switch does not indicate said achievement of said calibrated clutch pressure in a time proximate to said time span, indicating said clutch fill completion at an end of said time span; and

if said monitoring said output of said pressure switch indicates said achievement of said calibrated clutch pressure during said time span, indicating said clutch fill completion coincident to said output of said pressure switch.

5. The method of claim 3, further comprising:

monitoring said indicating said clutch fill completion based on said comparing over a plurality of clutch fill cycles;

determining an average clutch fill completion indication time; and

utilizing said average clutch fill completion indication time to control operation of said clutch.

6. The method of claim 1, further comprising:

estimating a clutch pressure based upon said clutch fill volume; and

estimating a clutch torque capacity based on said clutch pressure.

7. The method of claim 1, wherein monitoring said state of said pressure control switch operatively coupled to one of said clutches comprises:

monitoring forces acting upon a selecting mechanism within said pressure control switch; and

indicating said state of said pressure control switch based upon said monitoring said forces.

8. The method of claim 7, wherein indicating said state of said pressure control switch comprises:

if said monitoring said forces indicates said selecting mechanism is located to fully channel said hydraulic line pressure to said clutch, indicating a full feed state;

if said monitoring said forces indicates said selecting mechanism is located to block said hydraulic line pressure to said clutch and to exhaust a clutch pressure, indicating an exhaust state; and

if said monitoring said forces indicates said selecting mechanism is located select some intermediate pressure level to said clutch, indicating an overlap state.

9. Method for operating a powertrain comprising an electro-mechanical transmission adapted to selectively transmit mechanical power to an output member through selective application of a hydraulically actuated clutch, the method comprising:

monitoring factors affecting a hydraulic flow through a clutch control circuit;

determining said hydraulic flow through said clutch control circuit based upon said factors;

tracking a clutch fill volume of said clutch through integration of said hydraulic flow and estimation of an initial clutch fill volume; and

controlling operation of said clutch based upon said clutch fill volume; and

wherein monitoring said factors affecting hydraulic flow comprise;

monitoring a state of a pressure control switch controlling said hydraulic flow, wherein said state indicates flow paths currently selected for said clutch control circuit;

monitoring a clutch control circuit hydraulic flow resistance based upon said state of said pressure control switch;

monitoring a hydraulic line pressure available to actuate said clutch; and

estimating a pressure drop through said clutch control circuit based upon said state of said pressure control switch, said estimated hydraulic line pressure, an estimated clutch pressure, and a pressure of a hydraulic return line.

10. The method of claim 9, wherein controlling operation of said clutch comprises:

estimating a clutch fill completion time; and

indicating a clutch fill completion indicating said clutch is in a touching state.

11. The method of claim 10, wherein indicating said clutch fill completion comprises:

estimating a time span wherein achieving clutch fill completion is expected based upon said clutch fill volume and said hydraulic flow;

monitoring an output of a pressure switch operatively coupled to said clutch and indicating achievement of a clutch pressure calibrated to expected clutch fill completion;

comparing said time span wherein achieving clutch fill completion is expected and said output of said pressure switch; and

indicating said clutch fill completion based upon said comparing.

12. The method of claim 11, wherein indicating said clutch fill completion based upon said comparing comprises:

if said monitoring said output of said pressure switch indicates said achievement of said calibrated clutch pressure before said time span, indicating said clutch fill completion at a beginning of said time span;

if said monitoring said output of said pressure switch indicates said achievement of said calibrated clutch pressure after said time span, indicating said clutch fill completion at an end of said time span;

if said monitoring said output of said pressure switch does not indicate said achievement of said calibrated clutch pressure in a time proximate to said time span, indicating said clutch fill completion at an end of said time span; and

if said monitoring said output of said pressure switch indicates said achievement of said calibrated clutch pressure during said time span, indicating said clutch fill completion coincident to said output of said pressure switch.

13. The method of claim 11, further comprising:

monitoring said indicating said clutch fill completion based on said comparing over a plurality of clutch fill cycles;

determining an average clutch fill completion indication time; and

utilizing said average clutch fill completion indication time to control operation of said clutch.

14. The method of claim 9, further comprising:

estimating a clutch pressure based upon said clutch fill volume; and

estimating a clutch torque capacity based on said clutch pressure.

15. The method of claim 9, wherein said monitoring said state of a pressure control switch controlling said hydraulic flow comprises:

monitoring forces acting upon a selecting mechanism within said pressure control switch; and

indicating said state of said pressure control switch based upon said monitoring said forces.

16. The method of claim 15, wherein said indicating said state of said pressure control switch comprises:

if said monitoring said forces indicates said selecting mechanism is located to fully channel said hydraulic line pressure to said clutch, indicating a full feed state;

if said monitoring said forces indicates said selecting mechanism is located to block said hydraulic line pressure to said clutch and to exhaust a clutch pressure, indicating an exhaust state; and

if said monitoring said forces indicates said selecting mechanism is located select some intermediate pressure level to said clutch, indicating an overlap state.