METHOD FOR DETERMINING AN ACHIEVABLE TORQUE OPERATING REGION FOR A TRANSMISSION

• US 20090115350A1
• Filed: 10/16/2008
• Published: 05/07/2009
• Est. Priority Date: 11/01/2007
• 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), Daimler AG (Mercedes-Benz Group AG), GM Global Technology Operations Incorporated (Motors Liquidation Co. GUC Trust), Chrysler LLC (Stellantis NV)
• Inventors: Heap, Anthony H.
• Granted Patent: US 8,035,324 B2
• Time in Patent Office: Days
• US Class Current: 318/8
• 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 6/445 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 10/26 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 20/40 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 2050/0022 Gains, weighting coefficients or weighting functions
• CPC Class Codes: B60W 2510/0216 Clutch engagement rate
• CPC Class Codes: B60W 2510/0275 Clutch torque
• CPC Class Codes: B60W 2510/0657 Engine torque
• CPC Class Codes: B60W 2510/0661 Torque change rate
• CPC Class Codes: B60W 2510/083 Torque
• CPC Class Codes: B60W 2510/244 Charge state
• CPC Class Codes: B60W 2540/10 : Accelerator pedal position
• CPC Class Codes: B60W 2540/12 : Brake pedal position
• CPC Class Codes: B60W 2710/083 : Torque
• CPC Class Codes: B60W 2710/105 : Output torque
• CPC Class Codes: B60W 2710/1055 : Output torque change rate
• 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

A method for controlling a transmission operative to transfer power between an input member and torque machines and an output member includes determining available power, motor torque constraints, and other constraints on torque transfer. Equations are provided, transformed to a second coordinate system and simultaneously solved. An achievable torque operating region is determined.

Claims

1. A method for controlling a transmission operative to transfer power between an input member and first and second torque machines and an output member, the first and second torque machines connected to an energy storage device, the method comprising:

determining a range of available power from the energy storage device and motor torque constraints for the first and second torque machines;

providing equations for the range of available power from the energy storage device and the motor torque constraints for the first and second torque machines;

transforming the equations for the range of available power from the energy storage device and the motor torque constraints for the first and second torque machines to a second coordinate system;

simultaneously solving the transformed equations for the range of available power from the energy storage device and the motor torque constraints for the first and second torque machines; and

determining an achievable operating region for the transmission in the second coordinate system based upon the simultaneously solved transformed equations.

2. The method of claim 1, comprising providing equations representing maximum allowable charging power and a maximum allowable discharging power from the energy storage device.

3. The method of claim 2, wherein transforming the equations for the range of available power from the energy storage device to the second coordinate system comprises transforming the equations representing the maximum allowable charging power and maximum allowable discharging power to equations graphically represented as circles having a common center point.

4. The method of claim 3, wherein the common center point of the circles represents the maximum charging power from the first and second torque machines to the energy storage device.

5. The method of claim 3, comprising transforming the equations for the motor torque constraints for the first and second torque machines to the second coordinate system based upon the transformed equations for the range of available power from the energy storage device.

6. The method of claim 1, further comprising

providing an equation for a transmission torque term of interest for the transmission and transforming the equation to a second coordinate system;

simultaneously solving the transformed equations for the range of available power from the energy storage device, the motor torque constraints for the first and second torque machines, and the transmission torque term of interest; and

determining an achievable state for the transmission torque term of interest in the second coordinate system based upon the simultaneously solved transformed equations.

7. The method of claim 6, comprising retransforming the achievable state for the transmission torque term of interest to the first coordinate system.

8. The method of claim 1, comprising retransforming the achievable operating region for the transmission torque term of interest to the first coordinate system.

9. The method of claim 1, further comprising

determining a first constraint on torque transfer through the transmission comprising maximum and minimum acceleration rates of the input member;

determining a second constraint on torque transfer through the transmission comprising maximum and minimum output torques; and

determining an achievable operating region for the transmission based upon the range of available power from the energy storage device, the motor torque constraints for the first and second torque machines, and the first and second constraints on torque transfer through the transmission.

10. The method of claim 1, further comprising:

determining a first constraint on torque transfer through the transmission comprising maximum and minimum acceleration rates of the input member;

determining a second constraint on torque transfer through the transmission comprising maximum and minimum acceleration rates of the output member; and

determining an achievable operating region for the transmission based upon the range of available power from the energy storage device, the motor torque constraints for the first and second torque machines, and the first and second constraints on torque transfer through the transmission.

11. A method for controlling a transmission operative to transfer power between an input member and first and second torque machines and an output member by selectively applying a plurality of clutches, the first and second torque machines connected to an energy storage device, the method comprising:

determining a range of available power from the energy storage device, motor torque constraints for the first and second torque machines, and first and second constraints on torque transfer through the transmission;

providing equations for the range of available power from the energy storage device, the motor torque constraints for the first and second torque machines, and the first and second constraints on torque transfer through the transmission in a first coordinate system;

providing an equation for a transmission torque term of interest;

transforming the equations for the range of available power from the energy storage device, the motor torque constraints for the first and second torque machines, and the first and second constraints on torque transfer through the transmission to a second coordinate system;

transforming the equation for the transmission torque term of interest to the second coordinate system;

simultaneously solving the transformed equations for the range of available power from the energy storage device, the motor torque constraints for the first and second torque machines, the first and second constraints on torque transfer through the transmission, and the transmission torque term of interest;

determining an achievable operating region for the transmission in the second coordinate system based upon the simultaneously solved transformed equations; and

determining a preferred state for the transmission torque term of interest in the second coordinate system based upon achievable operating region for the transmission in the second coordinate system.

12. The method of claim 11, wherein the preferred state for the transmission torque term of interest comprises a maximum achievable state.

13. The method of claim 11, wherein the preferred state for the transmission torque term of interest comprises a minimum achievable state.

14. The method of claim 11, wherein the first constraint on torque transfer through the transmission comprises maximum and minimum input torques to the input member and the second constraint on torque transfer through the transmission comprises maximum and minimum clutch reactive torques of the selectively applied clutch.

15. The method of claim 11, wherein the first constraint on torque transfer through the transmission comprises maximum and minimum input torques to the input member and the second constraint on torque transfer through the transmission comprises maximum and minimum clutch speeds for an oncoming clutch.

16. A method for controlling a transmission operative to transfer power between an input member and torque machines and an output member, the torque machines connected to an energy storage device, the method comprising:

determining a range of available power from the energy storage device, motor torque constraints for the torque machines, and constraints on torque transfer through the transmission;

providing equations for the range of available power from the energy storage device, the motor torque constraints for the torque machines, and the constraints on torque transfer through the transmission in a first coordinate system;

transforming the equations for the range of available power from the energy storage device, the motor torque constraints for the torque machines, and the constraints on torque transfer through the transmission to a second coordinate system;

simultaneously solving the transformed equations for the range of available power from the energy storage device, the motor torque constraints for the torque machines, and the constraints on torque transfer through the transmission; and

determining an achievable operating region for the transmission in the second coordinate system based upon the simultaneously solved transformed equations.

17. The method of claim 16, further comprising:

providing an equation for a transmission torque term of interest;

transforming the equation for the transmission torque term of interest to the second coordinate system;

comparing the achievable operating region for the transmission with the transformed equation for the transmission torque term of interest; and

determining a preferred state for the transmission torque term of interest in the second coordinate system based upon achievable operating region for the transmission in the second coordinate system.