Hybrid vehicle control when towing

• US 9,505,400 B2
• Filed: 05/26/2015
• Issued: 11/29/2016
• Est. Priority Date: 10/14/2013
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Wright, Robert, Nefcy, Bernard D., Doering, Jeffrey Allen
• Primary Examiner(s): PANG, ROGER L
• Application Number:
  US14/721,339
• Publication Number:
  US 20150251654A1
• Time in Patent Office: 553 Days
• US Class Current: 1/1
• CPC Class Codes: B60K 2006/4825 Electric machine connected or connectable to gearbox input shaft
• 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 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 2510/083 Torque
• CPC Class Codes: B60W 2510/244 Charge state
• CPC Class Codes: B60W 2520/105 Longitudinal acceleration
• CPC Class Codes: B60W 2530/10 Weight
• CPC Class Codes: B60W 2530/16 Driving resistance
• CPC Class Codes: B60W 2540/12 Brake pedal position
• CPC Class Codes: B60W 2540/215 Selection or confirmation of options
• CPC Class Codes: B60W 2710/06 Combustion engines, Gas turbines
• CPC Class Codes: B60W 30/00 Purposes of road vehicle drive control systems not related to the control of a particular sub-unit, e.g. of systems using conjoint control of vehicle sub-units
• CPC Class Codes: B60W 30/18009 related to particular drive situations
• CPC Class Codes: B60W 30/18018 Start-stop drive, e.g. in a traffic jam
• CPC Class Codes: B60W 40/13 Load or weight
• CPC Class Codes: F02D 29/02 peculiar to engines driving vehicles; peculiar to engines driving variable pitch propellers
• CPC Class Codes: Y02T 10/40 Engine management systems
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y10S 903/902 Prime movers comprising electrical and internal combustion motors
• CPC Class Codes: Y10S 903/905 Combustion engine

Abstract

A method for controlling a hybrid vehicle having a trailer hitch includes detecting the trailer hitch being in use, commanding an engine to stop, and commanding the engine to start in response to a torque to accelerate being within a predetermined offset below an unladen vehicle torque pull up schedule.

Claims

1. A method for controlling a hybrid vehicle having a trailer hitch comprising:

detecting the hitch being in use;

commanding an engine to stop to increase fuel efficiency; and

in response to a torque to accelerate the vehicle being within a predetermined offset below an engine torque pull up schedule for an unladen vehicle, commanding the engine to start to reduce a time delay for starting the engine and increase vehicle torque to move the vehicle.

2. The method of claim 1 further comprising calculating a weight of a load connected to the hitch;

wherein the predetermined offset is based on the weight of the load.

3. The method of claim 2 wherein the predetermined offset increases with increasing trailer weight.

4. The method of claim 2 further comprising inputting the weight into a calibration table to determine the predetermined offset.

5. The method of claim 2 wherein the torque to accelerate the vehicle is based on the weight of the load.

6. The method of claim 5 further comprising measuring an actual vehicle acceleration;

wherein the weight of the load is calculated based on the actual vehicle acceleration compared to a grade based vehicle acceleration.

7. The method of claim 1 further comprising receiving a user input indicating a weight of a load connected to the hitch;

wherein the predetermined offset is based on the weight of the load.

8. The method of claim 1 wherein detecting the hitch being in use is based on receiving a signal from a trailer tow module.

9. The method of claim 1 wherein detecting the hitch being in use is based on receiving a signal from a manual switch.

10. The method of claim 1 further comprising comparing a weight of a load connected to the hitch to a threshold value;

and

setting the predetermined offset to zero if the weight is less than the threshold value.

11. The method of claim 1 wherein the engine is commanded to stop to increase fuel efficiency when a vehicle torque request is below the offset of the engine torque pull up schedule.

12. The method of claim 1 wherein the engine is commanded to start in response to the torque to accelerate the vehicle being within the predetermined offset below the engine torque pull up schedule for the unladen vehicle to reduce the time delay for starting the engine and increase vehicle torque to move the vehicle at a vehicle launch condition while slipping a downstream clutch, the downstream clutch connecting an electric machine to a transmission gearbox.

13. The method of claim 12 wherein the downstream clutch is a lockout clutch for a torque converter, and slipping the downstream clutch at a vehicle launch condition causes torque multiplication across the torque converter.

14. The method of claim 12 wherein a vehicle speed is substantially zero prior to the vehicle launch condition.

15. The method of claim 1 wherein the engine torque pull up schedule for an unladen vehicle is a function of an available vehicle electrical torque.

16. The method of claim 15 wherein the available vehicle electrical torque is a function of a traction battery state and a torque limit of an electric machine.