Engine control system for torque management in a hybrid powertrain system

• US 8,000,866 B2
• Filed: 10/14/2008
• Issued: 08/16/2011
• Est. Priority Date: 11/04/2007
• 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 LLC (Stellantis NV)
• Inventors: Heap, Anthony H., Sah, Jy-Jen F., Kaminsky, Lawrence A.
• Primary Examiner(s): Nguyen; Tan Q
• Application Number:
  US12/251,424
• Publication Number:
  US 20090118932A1
• Time in Patent Office: 1,036 Days
• Field of Search: 701/54, 701/22, 701/55, 701/56, 701/58, 180/65.7, 180/65.21, 180/65.285, 477/3, 477/110, 903/945, 903/902
• US Class Current: 701/54
• CPC Class Codes: B60K 1/02 comprising more than one electric motor
• CPC Class Codes: B60K 6/26 characterised by the motors or the generators
• 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 2240/486 Operating parameters
• 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 2050/0022 Gains, weighting coefficients or weighting functions
• CPC Class Codes: B60W 2510/0657 Engine torque
• CPC Class Codes: B60W 2510/085 Power
• CPC Class Codes: B60W 2510/10 Change speed gearings
• CPC Class Codes: B60W 2510/102 Input speed change rate
• CPC Class Codes: B60W 2540/10 Accelerator pedal position
• CPC Class Codes: B60W 2540/12 : Brake pedal position
• CPC Class Codes: B60W 2710/027 : Clutch torque
• 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: B60W 50/0097 : Predicting future conditions
• CPC Class Codes: F02D 11/105 : characterised by the function converting demand to actuation, e.g. a map indicating relations between an accelerator pedal position and throttle valve opening or target engine torque
• CPC Class Codes: F02D 2250/26 : by applying a torque limit
• CPC Class Codes: F02D 2400/12 : Engine control specially adapted for a transmission comprising a torque converter or for continuously variable transmissions
• CPC Class Codes: F02D 41/0215 : in relation with elements of the transmission
• CPC Class Codes: F02D 41/1497 : With detection of the mechanical response of the engine
• 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 3/728 : with means to change ratio in the mechanical gearing
• CPC Class Codes: Y02T 10/62 : Hybrid vehicles
• CPC Class Codes: Y02T 10/64 : Electric machine technologies in electromobility

Abstract

An engine is coupled to an input member of a hybrid transmission, the hybrid transmission operative to transfer power between the engine and a second torque machine and an output member. A method for controlling the engine includes monitoring an operator torque request, commanding operation of the hybrid transmission in a continuously variable operating range state, determining engine commands comprising a first engine torque request and a second engine torque request based upon the operator torque request and the operation of the hybrid transmission, determining an engine torque constraint comprising a maximum engine torque based upon a capacity of the hybrid transmission to react the engine torque, and controlling engine operation based upon the first engine torque request only when the second engine torque request exceeds the engine torque constraint.

Claims

1. Method for controlling an engine coupled to an input member of a hybrid transmission, the hybrid transmission operative to transfer power between the engine and a second torque machine and an output member, the method comprising:

monitoring an operator torque request;

commanding operation of the hybrid transmission in a continuously variable operating range state;

determining engine commands comprising a first engine torque request and a second engine torque request based upon the operator torque request and the operation of the hybrid transmission;

determining an engine torque constraint comprising a maximum engine torque based upon a capacity of the hybrid transmission to react the engine torque; and

controlling engine operation based upon the first engine torque request only when the second engine torque request exceeds the engine torque constraint.

2. The method of claim 1, further comprising controlling the engine operation based upon the second engine torque request when the second engine torque request is less than the engine torque constraint.

3. The method of claim 1, further comprising:

monitoring an acceleration rate of the input member; and

determining the maximum engine torque based upon the acceleration rate of the input member and the capacity of the hybrid transmission to react the engine torque.

4. The method of claim 1, further comprising controlling engine spark advance timing to achieve the first torque request when the second engine torque request exceeds the engine torque constraint.

5. The method of claim 1, further comprising controlling engine fuel injection timing to achieve the first torque request when the second engine torque request exceeds the engine torque constraint.

6. The method of claim 1, wherein the second engine torque request comprises a preferred engine torque determined based upon engine operation.

7. The method of claim 1, further comprising limiting the capacity of the hybrid transmission to react the engine torque input based upon a reactive torque limit across an applied clutch of the hybrid transmission.

8. The method of claim 7, further comprising determining the capacity of the hybrid transmission to react the engine torque input based upon power limits of the second power generating device.

9. The method of claim 1, comprising

monitoring operator inputs to an accelerator pedal and a brake pedal;

determining an immediate accelerator output torque and a net immediate output torque based upon the operator inputs to the accelerator pedal and the brake pedal; and

determining the engine torque constraints comprising the maximum engine torque based upon the immediate accelerator output torque and a net immediate output torque.

10. The method of claim 1, comprising

monitoring operator inputs to an accelerator pedal and a brake pedal;

determining a predicted accelerator output torque and a net predicted output torque based upon the operator inputs to the accelerator pedal and the brake pedal; and

determining the first engine torque request and the second engine torque request based upon the predicted accelerator output torque and a net predicted output torque.

11. The method of claim 1, further comprising:

determining an engine response type based upon the first and the second engine torque requests and the engine torque constraint comprising the maximum engine torque;

setting the engine response type to an active response only when the second engine torque request is outside the engine torque constraint; and

controlling the engine operation based upon the first engine torque request only when the engine response type is an active response.

12. Method for controlling an engine coupled to an input member of a hybrid transmission, the hybrid transmission operative to transfer power between the input member and a second torque machine and an output member, the hybrid transmission selectively operative in one of a plurality of fixed gear and continuously variable operating range states, the method comprising:

monitoring an operator torque request;

commanding a shift from a first fixed gear to a second fixed gear;

shifting operation of the hybrid transmission to a continuously variable operating range state and determining a preferred acceleration rate for the input member;

determining maximum and minimum input torque constraints to the hybrid transmission based upon a preferred acceleration rate for the input member;

determining maximum and minimum engine torque constraints based upon the maximum and minimum input torque constraints;

determining engine commands comprising a first engine torque request and a second engine torque request based upon the operator torque request; and

controlling engine operation based upon the first engine torque request only when the second engine torque request violates one of the maximum and minimum engine torque constraints.

13. The method of claim 12, further comprising determining the maximum and minimum input torque constraints to the hybrid transmission based upon a preferred acceleration rate for the input member and a capacity of the hybrid transmission to react the input torque.

14. The method of claim 13, further comprising:

connecting the second torque machine to an energy storage device; and

determining the capacity of the transmission to react the input torque based upon power limits of the energy storage device connected to the second torque machine.

15. The method of claim 14, further comprising determining the capacity of the transmission device to react the input torque based upon limitations of reactive torque across an applied clutch of the transmission device.

16. The method of claim 14, further comprising controlling the second torque machine to generate power storable in the energy storage device based upon the first engine torque request.

17. The method of claim 12, further comprising selecting a preferred engine state comprising one of a full fuel state and a fuel cutoff state and one of an all-cylinder state and a cylinder deactivation state.

18. Method for controlling a powertrain system comprising an engine coupled to an input member of a hybrid transmission, the hybrid transmission operative to transfer power between the input member and first and second torque machines and an output member, the first and second torque machines connected to an energy storage device and the hybrid transmission selectively operative in one of a plurality of operating range states, the method comprising:

commanding a shift in the hybrid transmission to a continuously variable operating range state;

determining a preferred acceleration rate for the input member;

determining maximum and minimum input torque constraints to the hybrid transmission based upon a preferred acceleration rate for the input member;

determining maximum and minimum engine torque constraints based upon the maximum and minimum input torque constraints;

determining engine commands comprising a first engine torque request and a second engine torque request based upon the operator torque request;

controlling operation of the engine based upon the first engine torque request only when the second engine torque request violates the maximum and minimum engine torque constraints; and

controlling operation of the first and second torque machines to generate power storable in the energy storage device based upon the preferred acceleration rate for the input member.