METHOD FOR STABILIZATION OF OPTIMAL INPUT SPEED IN MODE FOR A HYBRID POWERTRAIN SYSTEM

• US 20090118918A1
• Filed: 09/20/2008
• Published: 05/07/2009
• Est. Priority Date: 11/03/2007
• Status: Active Grant

• Current Assignee: Bayerische Motoren Werke AG, Daimler AG (Mercedes-Benz Group AG), Chrysler Group LLC (Stellantis NV)
• Original Assignee: BMW AG (Bayerische Motoren Werke AG), GM Global Technology Operations Incorporated (General Motors Company), Daimler AG (Mercedes-Benz Group AG), Chrysler LLC (Stellantis NV)
• Inventors: Heap, Anthony H., Kim, Kee Yong
• Granted Patent: US 8,406,970 B2
• Time in Patent Office: Days
• 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: 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 10/10 including control of change-speed gearings
• CPC Class Codes: B60W 10/105 of electric type
• CPC Class Codes: B60W 2540/10 Accelerator pedal position
• CPC Class Codes: B60W 2540/12 Brake pedal position
• CPC Class Codes: B60W 30/18 Propelling the vehicle
• CPC Class Codes: F16H 2037/106 with switching means to provide two variator modes or ranges
• CPC Class Codes: Y02T 10/40 Engine management systems
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y02T 10/84 Data processing systems or methods, management, administration

Abstract

A method for improving drivability of the powertrain system having an accelerator control includes determining a first transmission input speed having an associated first power loss and operating said transmission using said first transmission input speed. An operational parameter relating to said accelerator control is determined and a second transmission input speed responsive to said operational parameter and having an associated second power loss is determined. The value of at least one of said first and second power loss is biased based on said operational parameter. The first power loss is compared to said second power loss subsequent to the biasing. A third transmission input speed is determined and the transmission is operated using the third transmission input speed.

Claims

1. Method for improving drivability of a powertrain system having an accelerator control and including an engine coupled to an electro-mechanical transmission selectively operative in one of a plurality of transmission operating range states and one of a plurality of engine states, comprising:

determining a first transmission input speed, said first transmission input speed having an associated first power loss;

operating said transmission using said first transmission input speed;

determining an operational parameter relating to said accelerator control;

determining a second transmission input speed responsive to said operational parameter, said second transmission input speed having an associated second power loss;

biasing the value of at least one of said first and second power loss based on said operational parameter;

comparing said first power loss to said second power loss subsequent to said biasing;

determining a third transmission input speed; and

operating said transmission using said third transmission input speed.

2. A method according to claim 1 wherein said operational parameter comprise the position of said accelerator control.

3. A method according to claim 1 wherein said operational parameter comprises the rate of change of position of said accelerator control.

4. A method according to claim 3, in which said rate of change of position of said accelerator control is substantially zero, and said biasing is omitted.

5. A method according to claim 1 wherein determining a third transmission input speed is based on the comparison of said first power loss to said second power loss subsequent to said biasing.

6. A method according to claim 1 wherein said second transmission input speed responsive to said operational parameter is determined using the rate of change of position of said accelerator control as a function of time.

7. A method according to claim 1 wherein biasing the value of at least one of said first and second power loss is carried out using a cost function.

8. A method according to claim 7 wherein said cost function includes a gain component and an offset component.

9. A method according to claim 1 in which said first power loss is determined to be less than said second power loss, and said first transmission input speed is selected as a new input speed at which to operate said transmission at a future point in time.

10. A method according to claim 1 in which said third transmission input speed is less than said second transmission input speed.

11. A method according to claim 1 in which said third transmission input speed is greater than said second transmission input speed.

12. A method according to claim 1 in which said third transmission input speed is greater than said second transmission input speed by an amount equal to about the product of [d(transmission input speed)/dt] and [dt], in which dt is any amount of time between about one and about one thousand milliseconds, including all amounts of time and all intervals therebetween.

13. Method for controlling a powertrain system including an engine having an accelerator control, said engine coupled to an electro-mechanical transmission selectively operative in one of a plurality of transmission operating range states and one of a plurality of engine states, comprising:

determining a current transmission operating range state and engine state;

determining at least one potential transmission operating range state and engine state;

providing an operator torque request;

determining preferability factors associated with the current transmission operating range state and engine state, and potential transmission operating range states and engine states;

preferentially weighting the preferability factors for the current transmission operating range state and engine state;

selectively commanding changing the transmission operating range state and engine state based upon said preferability factors and said operator torque request; and

stabilizing an input speed to said transmission, responsive to changes in a position of said accelerator control.