Systems and method for multi-cylinder misfire detection

Patent metadata

Field	Value
Publication number	US-9951703-B2
Application number	US-201615219490-A
Country	US
Kind code	B2
Filing date	Jul 26, 2016
Priority date	Dec 16, 2014
Publication date	Apr 24, 2018
Grant date	Apr 24, 2018

Abstract

Various systems and methods are provided for identifying cylinder misfire. In one example, cylinder misfire may be identified based on a misfire monitor that differentiates a single-cylinder misfire event from a multi-cylinder misfire event based on output from a crankshaft speed sensor.

First claim

The invention claimed is:

1. A system comprising:
an engine having a plurality of cylinders coupled to a crankshaft;
a crankshaft speed sensor; and
a controller configured to:
receive an output from the crankshaft speed sensor, the received output from the crankshaft speed sensor sampled by the controller to obtain a sampled output;
process the sampled output to obtain a half order frequency signal and a first order frequency signal of the sampled output;
determine an amplitude of the half order frequency signal and an amplitude the first order frequency signal;
identify a cylinder misfire event, the cylinder misfire event being a single-cylinder misfire event where only one cylinder is misfiring or a multi-cylinder misfire event where more than one cylinder is misfiring;
differentiate the cylinder misfire event being the single-cylinder misfire event from the cylinder misfire event being the multi-cylinder misfire event based on the amplitude of the half order frequency signal and the amplitude of the first order frequency signal; and
adjust one or more engine operating parameters responsive to an indication of the single-cylinder misfire event differently from the multi-cylinder misfire event.

2. The system of claim 1 , wherein the plurality of cylinders is arranged into a first cylinder bank and a second cylinder bank, and wherein to differentiate the single-cylinder misfire event from the multi-cylinder misfire event, the controller is configured to indicate the single-cylinder misfire event responsive to the amplitude of the half order frequency signal being greater than a first threshold amplitude but less than a second threshold amplitude and further responsive to an exhaust gas temperature of the first cylinder bank being within a threshold range of an exhaust gas temperature of the second cylinder bank.

3. The system of claim 2 , wherein the controller is configured to indicate a first multi-cylinder misfire event responsive to the amplitude of the half order frequency signal being greater than the first threshold amplitude but less than the second threshold amplitude and further responsive to the exhaust gas temperature of the first cylinder bank being out of the threshold range of the exhaust gas temperature of the second cylinder bank.

4. The system of claim 3 , wherein the controller is configured to indicate a second multi-cylinder misfire event responsive to the amplitude of the half order frequency signal being greater than the second threshold amplitude.

5. The system of claim 4 , wherein the controller is configured to indicate a third multi-cylinder misfire event responsive to the amplitude of the half order frequency signal being less than the first threshold amplitude and further responsive to the amplitude of the first order frequency signal being greater than the first threshold amplitude.

6. The system of claim 5 , wherein the controller is configured to indicate a fourth multi-cylinder misfire event responsive to both the amplitude of the half order frequency signal and the amplitude of the first order frequency signal being within a threshold range of the first threshold amplitude.

7. The system of claim 1 , wherein the controller is configured to, responsive to indicating the single-cylinder misfire event, identify which cylinder is misfiring based on a phase of a selected frequency component signal of the output from the crankshaft speed sensor.

8. The system of claim 1 , wherein the controller is configured to perform a cylinder identification test responsive to indicating the multi-cylinder misfire event, the cylinder identification test including:
while the engine is operating at a speed below a threshold speed, sequentially increasing an amount of fuel supplied to each cylinder;
determining an amplitude of a half order frequency signal for each cylinder while that cylinder is receiving the increased amount of fuel; and
indicating a given cylinder is misfiring responsive to the amplitude for that cylinder being less than a misfire threshold amplitude.

9. The system of claim 1 , wherein the controller is configured to adjust one or more engine operating parameters by adjusting a fuel injection amount to a misfiring cylinder.

10. A vehicle comprising:
a chassis; and
the system of claim 1 attached to the chassis.

11. The vehicle of claim 10 , further comprising an alternator and at least one electric motor, the crankshaft coupled to the alternator for driving the alternator to generate electricity, and the alternator coupled to the at least one electric motor to power the at least one electric motor with the electricity for moving the vehicle.

12. A method for an engine comprising a plurality of cylinders arranged into a first cylinder bank and a second cylinder bank, the method comprising:
detecting a cylinder misfire event responsive to a first magnitude of a half-order frequency component of a signal output from a crankshaft speed sensor being within a misfire threshold range of magnitudes;
if an exhaust temperature of the first cylinder bank is within a threshold range of an exhaust temperature of the second cylinder bank, indicating that the cylinder misfire event is a single-cylinder misfire event;
if the exhaust temperature of the first cylinder bank is not within the threshold range of the exhaust temperature of the second cylinder bank, indicating that the cylinder misfire event is a multi-cylinder misfire event; and
adjusting one or more operating parameters responsive to detecting the cylinder misfire event.

13. The method of claim 12 , wherein detecting the cylinder misfire event comprises detecting the cylinder misfire event during maximum engine load conditions.

14. The method of claim 13 , further comprising detecting a cylinder misfire event during low engine load conditions while the engine is operating at a speed below a threshold speed by:
sequentially increasing an amount of fuel supplied to each cylinder;
for each cylinder, while that cylinder is receiving the increased amount of fuel, determining a second magnitude of a half order frequency component of the signal output by the crankshaft speed sensor; and
indicating a given cylinder is misfiring responsive to the second magnitude for that cylinder being less than a misfire threshold magnitude.

15. The method of claim 14 , further comprising determining a change in performance of a given cylinder based on a rate of change of the second magnitude for that cylinder over a duration.

16. The method of claim 12 , wherein detecting the cylinder misfire event, indicating that the cylinder misfire event is the single-cylinder misfire event, indicating that the cylinder misfire event is the multi-cylinder misfire event, and adjusting the one or more operating parameters are carried out by a controller having one or more processors, the controller communicatively coupled with the crankshaft speed sensor.

17. The method of claim 16 , wherein the engine and controller are operatively disposed in a vehicle.

18. A system, comprising:
an engine having a plurality of cylinders arranged into a first cylinder bank and a second cylinder bank, each cylinder coupled to a crankshaft;
a crankshaft speed sensor;
a first exhaust temperature sensor positioned to measure an exhaust temperature of the first cylinder bank;
a second exhaust temperature sensor positioned to measure an exhaust temperature of the second cylinder bank; and
a controller configured to:
differentiate a single-cylinder misfire event from a multi-cylinder misfire event based on freque

Assignees

• Gen Electric

Inventors

• Pathan Habeeb Khan
• Flynn Paul Lloyd
• Gangwal Pritamkumar
• Schreiner James Robert
• Haranahalli Panchakshari Bhanuprakash
• Bhattacharya Aninda
• Murugesan Ganesasubramanian
• Karunaratne Milan Palinda
• Cullen Daniel

Classifications

• F02D41/0025

  Controlling engines characterised by use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures · CPC title

• B61C7/04

  Locomotives or motor railcars with two or more different kinds or types of engines, e.g. steam and IC engines · CPC title

• B61C5/00

  Locomotives or motor railcars with IC engines or gas turbines (characterised by power transmission B61C9/00; engines F02) · CPC title

• F02D29/06

  peculiar to engines driving electric generators · CPC title

• F02D41/008 Primary

  Controlling each cylinder individually · CPC title