Method and apparatus for dynamic output torque limiting for a hybrid powertrain system

• US 8,321,100 B2
• Filed: 10/21/2008
• Issued: 11/27/2012
• Est. Priority Date: 11/05/2007
• 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.
• Primary Examiner(s): Trammell, James
• Assistant Examiner(s): Malhotra, Sanjeev
• Application Number:
  US12/254,862
• Publication Number:
  US 20090118941A1
• Time in Patent Office: 1,498 Days
• Field of Search: 701/22, 701/51, 701/54, 701/60, 701/87, 477/3, 477/5, 318/9
• US Class Current: 701/54
• 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 2240/445 Temperature
• 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 10/26 for electrical energy, e.g. batteries or capacitors
• 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 2050/0004 In digital systems, e.g. discrete-time systems involving sampling
• CPC Class Codes: B60W 2050/0006 Digital architecture hierarchy
• CPC Class Codes: B60W 2050/0064 using a remote, e.g. cordless, transmitter or receiver unit, e.g. remote keypad or mobile phone
• CPC Class Codes: B60W 2510/0671 Engine manifold pressure
• CPC Class Codes: B60W 2510/0676 Engine temperature
• CPC Class Codes: B60W 2510/1015 Input shaft speed, e.g. turbine speed
• CPC Class Codes: B60W 2510/104 Output speed
• CPC Class Codes: B60W 2510/105 : Output torque
• CPC Class Codes: B60W 2510/244 : Charge state
• CPC Class Codes: B60W 2510/246 : Temperature
• CPC Class Codes: B60W 2520/28 : Wheel speed
• 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 2710/0666 : Engine torque
• CPC Class Codes: B60W 2710/083 : Torque
• CPC Class Codes: B60W 30/188 : Controlling power parameters of the driveline, e.g. determining the required power
• CPC Class Codes: B60W 50/04 : Monitoring the functioning of the control system
• CPC Class Codes: B60W 50/10 : Interpretation of driver requests or demands
• 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 10/40 : 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 10/84 : Data processing systems or methods, management, administration

Abstract

A powertrain system includes a hybrid transmission device operative to transfer power between an input member and torque machines and an output member in one of a plurality of operating range states. The torque machines are connected to an energy storage device. A method for operating the powertrain system includes determining a permissible range of input operating points to the input member, determining ranges of motor torques for the torque machines, determining an available power range from the energy storage device, selecting a candidate input operating point within the permissible range of input operating points, and determining maximum and minimum achievable output torques transferable to the output member for the candidate engine operating point within the ranges of motor torques for the torque machines and within the available power range from the energy storage device in a candidate operating range state.

Claims

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

implementing a powertrain control scheme including a first control scheme operative to determine a preferred engine input speed and a preferred transmission operating range state, a second control scheme operative to determine a preferred engine operating point, and a third control scheme operative to determine an output torque command and motor torque commands for the torque machines;

executing the first control scheme to determine the preferred engine input speed and the preferred transmission operating range state based upon an operator torque request and a present output member speed;

determining a present engine input speed;

executing the second control scheme to determine the preferred engine operating point based upon the operator torque request, the preferred engine input speed, the present engine input speed, power costs and the preferred transmission operating range state;

commanding engine operation based upon the preferred engine operating point;

determining a present engine operating point and a present transmission operating range state; and

executing the third control scheme to determine the motor torque commands for the torque machines based upon the output torque command, the present engine operating point, and the present transmission operating range state.

2. The method of claim 1, further comprising:

determining a permissible range of engine operating points;

determining ranges of motor torques for the torque machines;

determining an available power range from the energy storage device;

selecting a candidate engine operating point within the permissible range of engine operating points;

determining maximum and minimum achievable output torques transferable to the output member for the candidate engine operating point within the ranges of motor torques for the torque machines and within the available power range from the energy storage device for each of a plurality of candidate transmission operating range states.

3. The method of claim 2, further comprising:

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

determining the operator torque request based upon the operator inputs to the accelerator pedal and the brake pedal; and

bounding the output torque command within the maximum and minimum achievable output torques transferable to the output member for the candidate engine operating point.

4. The method of claim 3, further comprising:

selecting a plurality of candidate engine operating points within the permissible range of engine operating points;

determining maximum and minimum achievable output torques transferable to the output member for each of the plurality of candidate engine operating points achievable within the ranges of motor torques for the torque machines and within the power range from the energy storage device;

determining the power cost associated with each of the plurality of candidate engine operating points for operating the hybrid transmission to achieve the output torque command;

assigning a second cost associated with each of the plurality of candidate engine operating points when the output torque command does not meet the output torque request for the candidate engine operating point; and

selecting one of the plurality of the candidate engine operating points having minimum power and second costs as the preferred engine operating point.

5. The method of claim 4, further comprising:

selecting a plurality of candidate engine operating points within the permissible range of engine operating points;

determining a preferred engine operating point comprising the candidate engine operating point having minimum power and second costs for each of the plurality of candidate transmission operating range states; and

selecting one of the plurality of the candidate transmission operating range states having a preferred engine operating point having minimum power and second costs as the preferred transmission operating range state.

6. The method of claim 1, wherein the preferred engine operating point and the present engine operating point comprise engine power.

7. The method of claim 1, wherein the preferred engine operating point and the present engine operating point comprise engine torque.