Method and system for boosted engine system

Patent metadata

Field	Value
Publication number	US-10815875-B2
Application number	US-201715474813-A
Country	US
Kind code	B2
Filing date	Mar 30, 2017
Priority date	Mar 30, 2017
Publication date	Oct 27, 2020
Grant date	Oct 27, 2020

Abstract

Methods and systems are provided for increasing vehicle maneuverability when operating on sand, snow, or rocky terrain, as well as while performing cornering and sliding maneuvers. Boost path actuators are held in positions that enable manifold pressure to be held above barometric pressure as torque demand changes, including when torque demand drops. Engine torque is reduced or raised via adjustments to one or more of fuel delivery, spark timing, and intake throttle opening.

First claim

The invention claimed is:

1. A vehicle method, comprising:
responsive to a decrease in operator torque demand:
fully closing each of an exhaust waste-gate valve coupled to a turbocharger turbine, a recirculation valve coupled to a turbocharger compressor, and a bypass valve coupled to a supercharger compressor staged upstream of the turbocharger compressor;
fully opening an intake throttle valve; and
actuating an electric motor coupled to the supercharger compressor.

2. The method of claim 1 , further comprising adjusting a variable cam timing to maintain intake and exhaust cams at a position for highest volumetric efficiency responsive to the decrease in operator torque demand.

3. The method of claim 1 , wherein actuating the electric motor includes commanding a full duty cycle to the electric motor.

4. The method of claim 1 , wherein the decrease in operator torque demand occurs while a vehicle is operated in a driver selected performance mode, wherein the selected performance mode includes one of operating the vehicle on a selected terrain, and operating the vehicle with selected maneuvers.

5. The method of claim 4 , wherein the selected performance mode includes one of a sand mode where the vehicle is driven on sandy terrain, a baja mode where the vehicle is driven on a rocky terrain, and a drift mode where the vehicle performs sliding maneuvers.

6. The method of claim 1 , further comprising maintaining a throttle inlet pressure above barometric pressure responsive to the decrease in operator torque demand.

7. The method of claim 1 , further comprising reducing engine torque output based on the decreased operator torque demand by shutting of fuel to one or more engine cylinders, a number of cylinder fuel injectors deactivated increased as the operator torque demand decreases.

8. The method of claim 1 , further comprising, in response to a decrease in margin to surge for the supercharger compressor, transiently opening the bypass valve, and when the margin to surge increases, returning the bypass valve to a fully closed position.

9. The method of claim 1 , wherein the decrease in operator torque demand is responsive to an operator pedal tip-out immediately following an operator pedal tip-in.

10. The method claim 1 , further comprising maintaining each of the exhaust waste-gate valve, the recirculation valve, and the bypass valve fully closed, the intake throttle valve fully open, and the electric motor actuated responsive to an operator selected vehicle launch mode.

11. A method for a vehicle engine, comprising:
responsive to a first operator pedal tip-out, maintaining manifold pressure above barometric pressure by adjusting one or more air path actuators; and
responsive to a second operator pedal tip-out, reducing manifold pressure to barometric pressure by adjusting the one or more air path actuators.

12. The method of claim 11 , wherein the first operator pedal tip-out occurs while a vehicle is operated in a performance mode, and wherein the second operator pedal tip-out occurs while the vehicle is operated in a default mode.

13. The method of claim 12 , wherein the performance mode is selectively actuated responsive to an operator selection received via a vehicle display or dashboard, the performance mode including one of a sand mode where the vehicle is operated on sand, and a baja mode where the vehicle is operated on rocky terrain and in low ambient humidity.

14. The method of claim 11 , wherein the one or more air path actuators adjusting responsive to the first operator pedal tip-out includes closing each of an exhaust waste-gate valve coupled to a turbocharger turbine, a recirculation valve coupled to a turbocharger compressor, a bypass valve coupled to a supercharger compressor staged upstream of the turbocharger compressor, and an intake throttle while actuating an electric motor coupled to the supercharger compressor, and wherein the one or more air path actuators adjusting responsive to the second operator pedal tip-out includes opening each of the exhaust waste-gate valve, the recirculation valve, and the bypass valve while reducing an opening of the intake throttle and while disabling the electric motor.

15. The method of claim 14 , wherein the one or more air path actuators adjusting responsive to the first operator pedal tip-out further includes adjusting a variable cam timing to maintain intake and exhaust cams at a position of highest volumetric efficiency, and wherein the one or more air path actuators adjusting responsive to the second operator pedal tip-out further includes adjusting the variable cam timing to move intake and exhaust cams away from the position of highest volumetric efficiency.

16. The method of claim 14 , further comprising, responsive to the first operator pedal tip-out, selectively disabling fuel injectors coupled to a number of cylinders, where the number of cylinders increases as an operator torque demand during the first operator pedal tip-out decreases, and responsive to the second operator pedal tip-out, reducing fuel delivered to all engine cylinders based on the reduced opening of the intake throttle.

17. The method of claim 14 , further comprising, during the first operator pedal tip-out, intermittently opening the bypass valve to move a pressure ratio across the supercharger compressor away from a surge limit, and intermittently disabling the electric motor responsive to a state of charge of a battery coupled to the electric motor falling below a threshold charge.

18. A vehicle system, comprising:
an engine having an intake;
a first intake compressor driven by an electric motor;
a second intake compressor driven by an exhaust turbine positioned downstream of the first intake compressor along the intake;
an intake throttle coupled downstream of the second intake compressor;
a waste-gate including a waste-gate valve coupled across the exhaust turbine;
a first compressor bypass including a first valve coupled across the first intake compressor;
a second compressor passage including a second valve coupled across the second intake compressor;
a fuel injector coupled to each cylinder of the engine;
a pressure sensor for estimating a manifold pressure at an inlet of the intake throttle;
a vehicle display including a plurality of operator selectable buttons; and
a controller with computer readable instructions stored on non-transitory memory for:
transitioning the engine to one of a sand or baja mode based on an operator selection received via the vehicle display; and
in response to a decrease in operator demanded torque while in the sand or baja mode, maintaining manifold pressure above barometric pressure by fully closing each of the waste-gate valve, the first valve, and the second valve, fully opening the intake throttle, and actuating the electric motor to a full duty cycle.

19. The system of claim 18 , wherein the controller includes further instructions for disabling the fuel injector coupled to a number of cylinders, the number of cylinders selected increased as the operator demanded torque decreases.

20. The system of claim 18 , wherein the controller includes further instructions for:
maintaining the engine in a default mode in response to absence of operator selection; and
in response to a decrease in operator demanded torque while in the default mode, reducing manifold pressure to barometric pressure by increasing an opening of each of the waste-gate valve, the first valve, and the second valve, while reducing an opening of the intake throttl

Assignees

• Ford Global Tech Llc

Inventors

• Xiao Baitao
• Hellstrom John Erik Mikael
• Banker Adam Nathan

Classifications

• B60K6/20

  the prime-movers consisting of electric motors and internal combustion engines, e.g. HEVs · CPC title

• F02B37/14 Primary

  {Control} of the alternation between {or the operation of} exhaust drive and other drive of a pump, e.g. dependent on speed · CPC title

• F02B37/18

  by bypassing exhaust {from the inlet to the outlet of turbine or to the atmosphere} · CPC title

• F02D41/107

  and deceleration · CPC title

• F02B37/04 Primary

  Engines with exhaust drive and other drive of pumps, e.g. with exhaust-driven pump and mechanically-driven second pump · CPC title