Engine error detection system
First Claim
1. A method for detecting misfire in an engine, the engine having a plurality of working chambers and being operated in a skip fire manner, the method comprising:
- assigning a window to a target firing opportunity;
attempting to fire a target working chamber during the target firing opportunity;
measuring a change in an engine parameter during the target firing opportunity;
using a multi-cylinder pressure model to help determine an expected change in the engine parameter during the target firing opportunity wherein the pressure model involves estimating pressure in a skipped working chamber, wherein the determination of the expected change in the engine parameter accounts for torque added or subtracted from the powertrain by an auxiliary power source;
based on a comparison between the expected change and the measured change, determining whether the target working chamber misfired.
1 Assignment
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Accused Products
Abstract
A variety of methods and arrangements for detecting misfire and other engine-related errors are described. In one aspect, a window is assigned to a target firing opportunity for a target working chamber. There is an attempt to fire a target working chamber during the target firing opportunity. A change in an engine parameter (e.g., crankshaft angular acceleration) is measured during the window. A model (e.g., a pressure model) is used to help determine an expected change in the engine parameter during the target firing opportunity. Based on a comparison of the expected change and the measured change in the engine parameter, a determination is made as to whether an engine error (e.g., misfire) has occurred.
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Citations
26 Claims
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1. A method for detecting misfire in an engine, the engine having a plurality of working chambers and being operated in a skip fire manner, the method comprising:
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assigning a window to a target firing opportunity; attempting to fire a target working chamber during the target firing opportunity; measuring a change in an engine parameter during the target firing opportunity; using a multi-cylinder pressure model to help determine an expected change in the engine parameter during the target firing opportunity wherein the pressure model involves estimating pressure in a skipped working chamber, wherein the determination of the expected change in the engine parameter accounts for torque added or subtracted from the powertrain by an auxiliary power source; based on a comparison between the expected change and the measured change, determining whether the target working chamber misfired. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A misfire detection system for determining whether a particular working chamber in an engine has misfired, the engine being operated in a skip fire manner, the misfire detection system comprising:
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an engine parameter measurement module that is arranged to; assign a window to a target firing opportunity; and measure a change in an engine parameter during the target firing opportunity; and a misfire detection module that is arranged to; use a pressure model to help determine an expected change in the engine parameter during the target firing opportunity wherein the pressure model involves estimating pressure in a skipped working chamber, wherein the determination of the expected change in the engine parameter accounts for torque added or subtracted from the powertrain by an auxiliary power source; and determine whether the target working chamber misfired based on a comparison between the expected change and the measured change. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16)
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17. A method for detecting misfire in an engine, the engine having a plurality of working chambers and being operated in a dynamic firing level modulation manner, the method comprising:
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assigning a window to a target firing opportunity; attempting to fire a target working chamber during the target firing opportunity; measuring a change in an engine parameter during the target firing opportunity; using a multi-cylinder pressure model to help determine an expected change in the engine parameter during the target firing opportunity wherein the pressure model involves estimating pressure in a skipped working chamber; and based on a comparison between the expected change and the measured change, determining whether the target working chamber misfired. - View Dependent Claims (18, 19, 20, 21)
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22. A misfire detection system for determining whether a particular working chamber in an engine has misfired, the engine being operated in a dynamic firing level modulation manner, the misfire detection system comprising:
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an engine parameter measurement module that is arranged to; assign a window to a target firing opportunity; and measure a change in an engine parameter during the target firing opportunity; and a misfire detection module that is arranged to; use a pressure model to help determine an expected change in the engine parameter during the target firing opportunity wherein the pressure model involves estimating pressure in a skipped working chamber; and determine whether the target working chamber misfired based on a comparison between the expected change and the measured change. - View Dependent Claims (23, 24, 25, 26)
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Specification