Vehicle system and method for controlling torque delivery during transmission engagements with road grade and mass estimation

• US 9,579,991 B2
• Filed: 10/02/2014
• Issued: 02/28/2017
• Est. Priority Date: 10/02/2014
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Yamazaki, Mark Steven, Yu, Hai, Nefcy, Bernard D., Nedorezov, Felix, Liang, Wei
• Primary Examiner(s): Burgess, Ramya
• Assistant Examiner(s): MANLEY, MARK ALAN
• Application Number:
  US14/504,489
• Publication Number:
  US 20160096446A1
• Time in Patent Office: 880 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: B60K 2006/4825 Electric machine connected or connectable to gearbox input shaft
• CPC Class Codes: B60K 6/48 Parallel type
• CPC Class Codes: B60L 15/2054 by controlling transmissions or clutches
• CPC Class Codes: B60L 15/2081 for drive off on a slope
• CPC Class Codes: B60L 2240/423 Torque
• CPC Class Codes: B60L 2240/642 Slope of road
• CPC Class Codes: B60L 2260/44 by parameter estimation
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• 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 20/30 Control strategies involving selection of transmission gear ratio control of change speed gearings, together with other vehicle sub-units B60W10/10; HEV transmission gearing B60K6/36; gearings and control thereof F16H
• CPC Class Codes: B60W 2050/0012 Feedforward or open loop systems
• CPC Class Codes: B60W 2530/10 Weight
• CPC Class Codes: B60W 2552/15 Road slope, i.e. the inclination of a road segment in the longitudinal direction
• CPC Class Codes: B60W 2710/083 Torque
• CPC Class Codes: B60W 30/19 Improvement of gear change, e.g. by synchronisation or smoothing gear shift
• CPC Class Codes: B60W 40/076 Slope angle of the road
• CPC Class Codes: B60W 40/13 Load or weight
• CPC Class Codes: B60Y 2400/79 Drive shafts, output shafts or propeller shafts
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y02T 10/64 Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/72 : Electric energy management in electromobility
• CPC Class Codes: Y02T 90/16 : Information or communication technologies improving the operation of electric vehicles
• CPC Class Codes: Y10S 903/902 : Prime movers comprising electrical and internal combustion motors

Abstract

A method according to an exemplary aspect of the present disclosure includes, among other things, controlling a torque output of an electric machine of an electrified vehicle based on estimated loads present during a transmission engagement of the electrified vehicle.

Claims

1. A method, comprising:

controlling a torque output of an electric machine of an electrified vehicle based on estimated loads present during a transmission engagement of the electrified vehicle, the controlling step is performed each time a shift device is moved from a neutral gear to a drive gear, and wherein the estimated loads are based on at least a road grade estimate, a vehicle mass estimate, driveline loads, and transmission pump loads.

2. The method as recited in claim 1, wherein the controlling step includes determining whether an input shaft of a transmission gearbox is spinning or stationary as the transmission engagement is initiated.

3. The method as recited in claim 1, wherein the estimated loads are based on an amount of inertia necessary to spin up an input shaft of a transmission gearbox.

4. The method as recited in claim 1, wherein the controlling step includes:

estimating the loads present during the transmission engagement; and

adjusting the torque output of the electric machine to compensate for the estimated loads.

5. The method as recited in claim 1, wherein the controlling step includes:

determining the road grade estimate; and

deriving a first torque compensation value from the road grade estimate.

6. The method as recited in claim 5, wherein the controlling step includes:

determining the vehicle mass estimate; and

deriving a second torque compensation value from the vehicle mass estimate.

7. The method as recited in claim 6, comprising deriving a third torque compensation value from the driveline loads and a fourth torque compensation value from the transmission pump loads.

8. The method as recited in claim 7, comprising determining a feed-forward torque by adding the first torque compensation value, the second torque compensation value, the third torque compensation value and the fourth torque compensation value.

9. The method as recited in claim 8, wherein the controlling step includes modifying the torque output based on the feed-forward torque and a feedback torque.

10. The method as recited in claim 7, comprising deriving a fifth torque compensation value based on an amount of inertia required to spin up an input shaft of a transmission gearbox.

11. The method as recited in claim 10, comprising determining a feed-forward torque by adding the first torque compensation value, the second torque compensation value, the third torque compensation value, the fourth torque compensation value, and the fifth torque compensation value.

12. The method as recited in claim 11, wherein the controlling step includes modifying the torque output based on the feed-forward torque and a feedback torque.

13. The method as recited in claim 1, wherein the electrified vehicle is a modular hybrid transmission (MHT) vehicle.

14. A vehicle system, comprising:

a transmission gearbox;

an electric machine that supplies torque to an input shaft of said transmission gearbox;

a torque converter disposed between said electric machine and said transmission gearbox; and

a control unit in communication with said electric machine and configured to modify a torque output of said electric machine to compensate for variations in road grade and vehicle mass during a transmission engagement.

15. The vehicle system as recited in claim 14, comprising a transmission pump pressurized by said electric machine.

16. The vehicle system as recited in claim 14, wherein said control unit is configured to estimate loads present during said transmission engagement and compensate for said estimated loads by modifying said torque output.

17. The vehicle system as recited in claim 14, comprising a shift device that actuates said transmission engagement when moved from a neutral gear to a drive gear.

18. The vehicle system as recited in claim 14, wherein said control unit is configured to modify said torque output to additionally compensate for variations in driveline loads and transmission pump loads during the transmission engagement.