Vehicle anti-lock exhaust brake control system

Patent metadata

Field	Value
Publication number	US-10087869-B2
Application number	US-201615086831-A
Country	US
Kind code	B2
Filing date	Mar 31, 2016
Priority date	Mar 31, 2016
Publication date	Oct 2, 2018
Grant date	Oct 2, 2018

Abstract

A method of exhaust braking a vehicle includes determining a wheel slip ratio based on input from vehicle sensors. Based on a determination that the wheel slip ratio is unstable, the method further includes sending a command to reduce exhaust braking. Based on a determination that exhaust braking is reduced, the method further includes determining a change in wheel slip ratio over time based on input from the vehicle sensors. Based on a determination that the change in wheel slip ratio over time is stabilizing, the method further includes sending a command to increase exhaust braking.

First claim

What is claimed is:

1. A method of exhaust braking a vehicle, comprising:
sending a command to activate exhaust braking;
while the exhaust braking is active, determining a wheel slip ratio based on input from vehicle sensors; and
in response to a determination that a wheel slip condition is unstable based on the wheel slip ratio:
sending a command to reduce the exhaust braking;
during a period of reduced exhaust braking, determining an updated wheel slip ratio based on updated input from the vehicle sensors;
determining a change in the wheel slip ratio based on the updated input from the vehicle sensors;
in response to a determination that the wheel slip condition is unstable based on the updated wheel slip ratio and based on a determination that the change in wheel slip ratio indicates the wheel slip condition will remain unstable, sending a command to reduce the exhaust braking; and
in response to a determination that the wheel slip condition is unstable based on the updated wheel slip ratio and based on a determination that the change in wheel slip ratio indicates the wheel slip condition will become stable, sending a command to increase the exhaust breaking.

2. The method of claim 1 , wherein the determination that the wheel slip condition is unstable is based on a predetermined drop in speed for one or more wheels of the vehicle as compared to a vehicle speed.

3. The method of claim 1 , wherein the determination that the wheel slip condition is unstable is based on the wheel slip ratio being outside a range indicating that the wheel slip condition is stable.

4. The method of claim 3 , wherein the determination that the wheel slip condition is unstable is based on a change in the wheel slip ratio indicating that the wheel slip ratio is headed away from a range indicating that the wheel slip condition is stable.

5. The method of claim 3 , wherein the determination that the change in wheel slip ratio indicates the wheel slip condition will become stable is based on the change in wheel slip ratio indicating that the wheel slip ratio is headed toward the range indicating that the wheel slip condition is stable.

6. The method of claim 1 , wherein reducing the exhaust braking includes modifying a position of a component within one of an exhaust system and a turbocharger of the vehicle to increase engine torque.

7. The method of claim 1 , wherein increasing the exhaust braking includes modifying a position of a component within one of an exhaust system and a turbocharger of the vehicle to decrease engine torque.

8. The method of claim 1 , further comprising:
in response to a determination that the wheel slip condition is unstable based on the change in wheel slip ratio, sending a command to further reduce the exhaust braking.

9. The method of claim 1 , further comprising:
in response to a determination that the exhaust braking is increased, determining whether the exhaust breaking equals a maximum exhaust braking based on input from the vehicle sensors;
in response to a determination that the exhaust braking does not equal the maximum exhaust braking, determining a change in wheel slip ratio during a period of increased exhaust braking based on input from the vehicle sensors; and
in response to a determination that the wheel slip condition is stable based on the change in wheel slip ratio during the period of increased exhaust braking, sending a command to further increase the exhaust braking.

10. A controlling component, comprising:
a non-transitory memory; and
a processor configured to execute instructions stored in the non-transitory memory to:
send a command to activate exhaust braking;
while the exhaust braking is active, determine a wheel slip ratio based on input from vehicle sensors; and
in response to a determination that a wheel slip condition is unstable based on the wheel slip ratio:
send a command to reduce the exhaust braking;
during a period of reduced exhaust braking, determine an updated wheel slip ratio based on updated input from the vehicle sensors;
determine a change in the wheel slip ratio based on the updated input from the vehicle sensors;
in response to a determination that the wheel slip condition is unstable based on the updated wheel slip ratio and based on a determination that the change in wheel slip ratio indicates the wheel slip condition will remain unstable, send a command to reduce the exhaust braking; and
in response to a determination that the wheel slip condition is unstable based on the updated wheel slip ratio and based on a determination that the change in wheel slip ratio indicates the wheel slip condition will become stable, send a command to increase the exhaust breaking.

11. The controlling component of claim 10 , wherein the determination that the wheel slip condition is unstable is based on the wheel slip ratio being outside a range indicating that the wheel slip condition is stable and on a change in wheel slip ratio indicating that the wheel slip ratio is headed away from the range indicating that the wheel slip condition is stable.

12. The controlling component of claim 11 , wherein the determination that the change in wheel slip ratio indicates the wheel slip condition will become stable is based on the change in the wheel slip ratio indicating that the wheel slip ratio is headed toward the range indicating that the wheel slip condition is stable.

13. The controlling component of claim 10 , wherein reducing the exhaust braking and increasing the exhaust braking include modifying a position of a component within one of an exhaust system and a turbocharger of a vehicle to respectively increase and decrease engine torque.

14. The controlling component of claim 10 , wherein the processor is further configured to:
in response to a determination that the wheel slip condition is unstable based on the change in wheel slip ratio, send a command to further reduce the exhaust braking.

15. The controlling component of claim 10 , wherein the processor is further configured to:
in response to a determination that the exhaust braking is increased, determine whether the exhaust braking equals a maximum exhaust braking based on input from the vehicle sensors;
in response to a determination that the exhaust braking does not equal the maximum exhaust braking, determine the change in wheel slip ratio during a period of increased exhaust braking based on input from the vehicle sensors; and
in response to a determination that the wheel slip condition is stable based on the change in wheel slip ratio during the period of increased exhaust braking, send a command to further increase the exhaust braking.

16. A vehicle, comprising:
sensors disposed on the vehicle; and
a controlling component in communication with the vehicle sensors, comprising:
a non-transitory memory; and
a processor configured to execute instructions stored in the non-transitory memory to:
send a command to activate exhaust braking;
while the exhaust braking is active, determine a wheel slip ratio based on input from the vehicle sensors;
in response to a determination that a wheel slip condition is unstable based on the wheel slip ratio, send a command to reduce the exhaust braking;
in response to a determination that the wheel slip condition is stable based on the wheel slip ratio, maintain the exhaust braking at a current level;
during a period of reduced exhaust braking, determine an updated wheel slip ratio based on updated input from the vehicle sensors;
determine a change in wheel slip ratio based on the updated input from the vehicle sensors;
in respo

Assignees

• Nissan North America Inc

Inventors

• Tullock Zachary

Classifications

• F02D41/26 Primary

  using computer, e.g. microprocessor · CPC title

• F02D41/0007 Primary

  for control of turbo-charged or super-charged engines (control of the pumps per se F02B37/12) · CPC title

• F02D2200/501

  Vehicle speed · CPC title

• F02D2250/34

  Control of exhaust back pressure, e.g. for turbocharged engines · CPC title

• F02D2250/18

  Control of the engine output torque · CPC title