Engine Shut-Off Valve Control for Accurate Stuck-Open Detection
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Solution Overview
Problem
Existing methods for determining if a shut-off valve in an internal combustion engine is stuck open can lead to erroneous results during fuel cutoff processes, as the passage fuel pressure does not decrease as expected, leading to false positives.
Innovation Solution
A controller that outputs a valve closing signal and measures the passage fuel pressure decrease over a specified period, excluding the fuel cutoff process period, to accurately determine if the shut-off valve is stuck open.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the determination process is executed during fuel injection to detect stuck-open shut-off valve, then the accuracy of valve status detection is improved, but false positives occur during fuel cutoff process
Solution Approach 1:
The determination process dynamically adapts to engine operating conditions by detecting whether the engine is in fuel injection mode or fuel cutoff mode. The processing circuitry adjusts the determination logic based on the current operational state, enabling accurate stuck-open detection during fuel injection while preventing false positives during fuel cutoff operations.
Solution Approach 2:
The system changes the determination parameters based on the fuel injection status. When fuel cutoff is detected, the system modifies the pressure decrease evaluation criteria or excludes this period from determination, thereby maintaining measurement precision while avoiding unreliable determinations during transient fuel cutoff states.
2Speed
If the determination process monitors passage fuel pressure continuously, then the response time for detecting stuck-open valve is improved, but the likelihood of erroneous determination during fuel cutoff increases
Solution Approach 1:
The determination process is executed periodically during fuel injection phases rather than continuously. The processing circuitry monitors passage fuel pressure continuously but performs the actual determination only during appropriate periods when fuel injection is active, maintaining fast response capability while avoiding erroneous determinations during fuel cutoff periods.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach reduces the likelihood of erroneous determinations of a stuck-open state by accounting for fuel cutoff processes, ensuring accurate valve status assessment.
Implementation Method 1
a pressure sensor disposed in a portion of the fuel passage between the shut-off valve and the fuel injection valve and configured to detect a passage fuel pressure that is a pressure of the fuel in the portion
Data Source
AI summary
An internal combustion engine includes a fuel tank, a fuel injection valve, a fuel passage, a shut-off valve disposed in the fuel passage, and a pressure sensor that detects a passage fuel pressure that is a pressure of fuel in a portion of the fuel passage between the shut-off valve and the fuel injection valve. The controller outputs a valve closing signal to the shut-off valve, and executes a determination process of determining whether the shut-off valve is stuck open based on a decrease amount of the passage fuel pressure that occurs until an elapsed period after the valve closing signal is output reaches a predetermined specified period. The controller excludes, from the elapsed period, a period in which a fuel cutoff process for stopping fuel injection by the fuel injection valve during operation of the internal combustion engine is executed.