Method for controlling vehicle launch

• US 8,612,113 B2
• Filed: 06/30/2011
• Issued: 12/17/2013
• Est. Priority Date: 06/30/2011
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Gibson, Alex O'Connor, DeMarco, John Anthony, Grant, Robert Michael, Gale, Allan Roy
• Primary Examiner(s): Tran, Khoi
• Assistant Examiner(s): RINK, RYAN J
• Application Number:
  US13/174,559
• Publication Number:
  US 20130002210A1
• Time in Patent Office: 901 Days
• Field of Search: 701/99, 180/443, 180/446
• US Class Current: 701/99
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/20 including control of steering systems
• CPC Class Codes: B60W 10/30 including control of auxiliary equipment, e.g. air-conditioning compressors or oil pumps
• CPC Class Codes: B60W 2540/10 Accelerator pedal position
• CPC Class Codes: B60W 2540/18 Steering angle
• CPC Class Codes: B60W 2710/0666 Engine torque
• CPC Class Codes: B60W 2710/083 Torque
• CPC Class Codes: B60W 2710/202 Steering torque
• CPC Class Codes: B60W 2710/305 target power to auxiliaries
• CPC Class Codes: B60W 30/18018 Start-stop drive, e.g. in a traffic jam
• CPC Class Codes: B60W 30/18027 Drive off, accelerating from standstill
• CPC Class Codes: B60W 30/1886 Controlling power supply to auxiliary devices
• CPC Class Codes: B60W 30/192 Mitigating problems related to power-up or power-down of the driveline, e.g. start-up of a cold engine
• CPC Class Codes: B62D 5/0481 monitoring the steering system, e.g. failures
• CPC Class Codes: H02P 9/008 wherein the generator is controlled by the requirements of the prime mover

Abstract

A method for improving starting of an engine that may be repeatedly stopped and started is presented. In one embodiment, the method adjusts a transmission actuator in response to engine combustion during an engine start. The method may improve vehicle launch for stop/start vehicles.

Claims

1. A method for an engine, comprising:

adjusting alternator output to a steering system via an electronic control system based on steering system available power until engine speed is below a threshold in response to an automatic engine stop request; and

during an automatic engine restart after stopping the engine, adjusting, via the electronic control system, a load of an alternator applied to the engine in response to a steering input and an engine torque request.

2. The method of claim 1, where the load of the alternator is adjusted in response to a weighting of the steering input and a weighting of the engine torque request.

3. The method of claim 1, where the load of the alternator is adjusted during the restart by applying an amount of alternator field current to the alternator until a threshold vehicle condition is exceeded.

4. The method of claim 3, where the threshold vehicle condition is at least one of a vehicle speed, engine speed, vehicle acceleration rate, and engine acceleration rate.

5. The method of claim 1, where the load of the alternator is adjusted via adjusting a field current of the alternator.

6. The method of claim 1, where a load of the alternator applied to the engine is applied during engine cranking and is limited via supplying substantially zero current to the alternator.

7. The method of claim 1, further comprising decreasing a torque supplied to vehicle wheels in response to an increased steering angle request.

8. The method of claim 1, further comprising increasing the load of the alternator applied to the engine in response to an increased steering angle request.

14. The method of claim 1, further comprising, after the automatic engine stop request, after engine speed falls below the threshold, and before the automatic engine restart, supplying power from a vehicle battery to the steering system if a charge of the battery is greater than a threshold.

9. A method for automatically restarting an engine after an automatic stop of the engine, comprising:

automatically restarting the engine after an automatic stop of said engine;

in a first mode where an operator input is less than a threshold,

adjusting, via an electronic control system, an alternator load applied to an engine to control engine speed and limit a voltage drop caused by an electric power steering system;

in a second mode where the operator input is greater than the threshold,

adjusting, via the electronic control system, the alternator load applied to the engine responsive to the operator input and a steering input; and

wherein operation in the first or second mode is allowed to commence based on a number of combustion events since the automatic engine stop.

10. The method of claim 9, where the operator input is an accelerator command.

11. The method of claim 9, where the first and second modes are entered after engine cranking and before a threshold vehicle condition is met.

12. The method of claim 11, where the threshold vehicle condition is one of a vehicle speed, vehicle acceleration, engine speed, and engine acceleration.

13. The method of claim 11, where during engine cranking current supplied to the electric power steering system is limited.

15. A launch control method for a vehicle, comprising:

in response to an automatic engine stop request, adjusting, via an electronic control system, alternator output to a power steering system of the vehicle based on an available power of the power steering system until engine speed falls below a threshold, and then supplying power from a battery of the vehicle to the power steering system if a charge of the battery is greater than a threshold;

during an automatic engine restart after the stop request;

during higher steering operation conditions, diverting a greater amount of engine output away from forward progress wheel torque generation and to the power steering system via the electronic control system; and

during lower steering operation conditions, diverting a lesser amount of engine output away from forward progress wheel torque generation and to the power steering system via the electronic control system.

16. The method of claim 15, where higher steering operating conditions include steering torque request greater than a threshold, steering torque output greater than a threshold, and steering angle greater than a threshold.

17. The method of claim 15, where the diverting occurs during an engine start before engine speed reaches a threshold and before engine torque reaches a threshold.

18. The method of claim 17, where the diverting begins during an engine start after a starter is disengaged.