Exhaust valve failure diagnostics and management

Patent metadata

Field	Value
Publication number	US-11624335-B2
Application number	US-202217569722-A
Country	US
Kind code	B2
Filing date	Jan 6, 2022
Priority date	Jan 11, 2021
Publication date	Apr 11, 2023
Grant date	Apr 11, 2023

Abstract

A method of operating an engine is provided. An exhaust valve actuation fault is detected for a first exhaust valve associated with a first cylinder during a first working cycle. In response to the detection of the exhaust valve actuation fault, fueling to at least the first cylinder is cut off. Actuation of the first exhaust valve is attempted in second working cycles that follow the first working cycle, wherein the second working cycles are not fueled. Whether or not the first exhaust valve actuated properly during the second working cycles is determined. Operation of the first cylinder is resumed when it is determined that the first exhaust valve actuated properly. Operation of the first cylinder is not resumed when it is determined that the first exhaust valve did not actuate properly.

First claim

What is claimed is:

1. A method of operating an engine having a plurality of cylinders, each cylinder having an associated intake valve and an associated exhaust valve, the method comprising:
detecting an exhaust valve actuation fault for a first exhaust valve of the exhaust valves during a first working cycle, the first exhaust valve being associated with a first cylinder;
in response to the detection of the exhaust valve actuation fault, cutting off fueling to at least the first cylinder;
attempting to actuate the first exhaust valve in a set of one or more second working cycles that follows the first working cycle in the first cylinder, wherein the one or more second working cycles are not fueled;
for each of the one or more second working cycles, determining whether the first exhaust valve actuated properly during the set of one or more second working cycles;
resuming operation of the first cylinder when it is determined that the first exhaust valve actuated properly during the set of one or more second working cycles; and
not resuming operation of the first cylinder when it is determined that the first exhaust valve did not actuate properly during the set of one or more second working cycles.

2. The method, as recited in claim 1 , wherein:
the engine is configured such that a set of the exhaust valves, including the first exhaust valve, are activated or deactivated as a group;
fuel is cut off to each of the cylinders in the group in response to the detection of the exhaust valve actuation fault; and
the method further comprises attempting to actuate the exhaust valves associated with each of the cylinders in the group, including the first cylinder during one or more second working cycles that follow the first working cycle wherein none of the cylinders in the group are fueled during the one or more second working cycles and a determination of whether to resume operation of the first cylinder is a determination of whether to resume operation of all of the cylinders in the group.

3. The method, as recited in claim 2 , wherein the set of the exhaust valves comprises all of the exhaust valves of the engine.

4. The method, as recited in claim 1 , wherein the determination of whether the first exhaust valve actuated properly during the one or more second working cycles is based at least in part on one or more of detected angular acceleration of a crankshaft, detected exhaust gas oxygen, detected exhaust manifold pressure, detected movement of exhaust valve by a proximity sensor, and detected intake manifold pressure (MAP).

5. The method, as recited in claim 1 , wherein the operating the engine uses a dynamic skip fire operation, and wherein the dynamic skip fire operation removes the first cylinder from all skip fire sequences as a result of detecting the exhaust valve actuation fault and adds the first cylinder to skip fire sequences on the resuming operation of the first cylinder.

6. The method, as recited in claim 5 , wherein each exhaust valve is controlled individually, so that fuel is only cut off to the first cylinder and only the first cylinder is removed from all of the skip fire sequences.

7. The method, as recited in claim 1 , wherein each exhaust valve is controlled individually, so that fuel is only cut off to the first cylinder.

8. The method, as recited in claim 1 , further comprising using an electric motor to power the engine when fuel is cut off to at least the first cylinder.

9. The method, as recited in claim 8 , further comprising allowing a violation of at least one of a state of charge limit and a current draw limit, while using the electric motor to power the engine when fuel is cut to the first cylinder.

10. A system comprising:
an engine; and
an engine control unit programmed to perform the method recited in claim 1 .

11. A method of operating an engine having a plurality of cylinders, each cylinder having an associated intake valve and an associated exhaust valve, the method comprising:
detecting an exhaust valve actuation fault for a first exhaust valve of the exhaust valves during a first working cycle, the first exhaust valve being associated with a first cylinder;
in response to the detection of the exhaust valve actuation fault, cutting off fueling to at least the first cylinder;
attempting to actuate the first exhaust valve in a set of one or more engine cycles that follows the first working cycle, wherein the first cylinder is not fueled during the set of one or more engine cycles;
utilizing an electric motor to maintain at least one of a desired drive torque and a desired crankshaft rotation speed during the set of one or more engine cycles; and
determining whether to resume operation of the first cylinder based at least in part on whether at least some of the attempts to actuate the first exhaust valve in the set of one or more engine cycles are successful.

12. A method as recited in claim 11 , wherein the electric motor is controlled to maintain at least a minimum engine speed during the attempting to actuate the first exhaust valve in the set of one or more engine cycles.

13. The method, as recited in claim 11 , wherein:
the engine is configured such that a set of the exhaust valves, including the first exhaust valve, are activated or deactivated as a group;
fuel is cut off to each of the cylinders in the group in response to the detection of the exhaust valve actuation fault; and
the method further comprises attempting to actuate the exhaust valves associated with each of the cylinders in the group, including the first cylinder during one or more engine cycles that follow the first working cycle wherein none of the cylinders in the group are fueled during the one or more engine cycles and a determination of whether to resume operation of the first cylinder is a determination of whether to resume operation of all of the cylinders in the group.

14. The method, as recited in claim 13 , wherein the set of the exhaust valves comprises all of the exhaust valves of the engine.

15. The method, as recited in claim 11 , wherein the determination of whether the first exhaust valve actuated properly during the one or more working cycles is based at least in part on one or more of detected angular acceleration of a crankshaft, exhaust gas oxygen, detected exhaust manifold pressure, detected movement of exhaust valve by a proximity sensor, and detected intake manifold pressure (MAP).

16. The method, as recited in claim 11 , wherein the operating the engine uses a dynamic skip fire operation, and wherein the dynamic skip fire operation removes the first cylinder from all skip fire sequences as a result of detecting the exhaust valve actuation fault and adds the first cylinder to skip fire sequences on the resuming operation of the first cylinder.

17. The method, as recited in claim 11 , further comprising allowing a violation of state of charge and/or current draw limits, while using the electric motor to power the engine when fuel is cut to at least the first cylinder.

18. A system comprising:
an engine;
an electric motor; and
an engine control unit programmed to perform the method recited in claim 11 .

19. A controller for controlling an engine having a plurality of cylinders, each cylinder having an associated intake valve and an associated exhaust valve, wherein the controller is configured to provide steps comprising:
detecting an exhaust valve actuation fault for a first exhaust valve of the exhaust valves during a first working cycle, the first exhaust valve being associated with a firs

Assignees

• Tula Technology Inc

Inventors

• Wang Robert C
• Serrano Louis J
• Chen Shikui Kevin

Classifications

• F02D13/06

  Cutting-out cylinders · CPC title

• F02D2200/503

  Battery correction, i.e. corrections as a function of the state of the battery, its output or its type · CPC title

• F02D13/0242

  Variable control of the exhaust valves only · CPC title

• F02D41/221 Primary

  relating to the failure of actuators or electrically driven elements · CPC title

• F02D41/1498

  measuring engine roughness · CPC title