Valve Leakage Detection via Crankshaft-Correlated Manifold Pressure
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Valve leakage in vehicle engine intake and exhaust manifolds can lead to engine misfires, damage to aftertreatment systems, and excess heat, which existing methods fail to detect effectively in a timely manner.
Innovation Solution
A method involving the acquisition of pressure data points correlated with crankshaft angular positions to identify deviations from a steady periodic pattern, with a test value determined to detect valve leakage by comparing these data points to a threshold value, using pattern recognition algorithms to determine if a valve is leaking.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If existing methods are used to monitor manifold pressure, then some valve leakage detection capability is provided, but timely and accurate detection of valve leakage is not achieved
Solution Approach 1:
The method performs preliminary analysis by establishing a reference periodic pressure pattern under normal operating conditions before actual leakage detection. This reference pattern is created by monitoring manifold pressure over multiple crankshaft cycles and identifying the expected periodic behavior, enabling timely comparison and detection when deviations occur during actual operation.
Solution Approach 2:
The method continuously compares real-time manifold pressure data against the established periodic reference pattern, creating a feedback mechanism that immediately identifies deviations indicating valve leakage. This feedback loop enables timely detection by constantly monitoring whether actual pressure values match the expected periodic behavior under steady-state conditions.
2Measurement precision
If pressure data is sampled without correlation to crankshaft angular positions, then data acquisition is simpler, but periodic patterns indicative of valve operation cannot be identified
Solution Approach 1:
The method transforms the pressure data by adding a temporal dimension through correlation with crankshaft angular positions. Instead of simple time-series sampling, the pressure values are mapped to specific crankshaft angle positions, creating a two-dimensional representation that reveals periodic patterns corresponding to valve opening and closing events throughout the engine cycle.
3Reliability
If valve leakage is not detected in time, then engine operation continues normally, but engine misfires and damage to aftertreatment systems occur
Solution Approach 1:
The control unit continuously monitors manifold pressure and compares it against the periodic reference pattern, creating a real-time feedback system that detects valve leakage deviations. When deviations exceed predetermined thresholds, the system immediately identifies the leakage condition, enabling timely protective actions to prevent engine misfires and damage to aftertreatment systems.
Data Source
Figure 1A
Figure 1B
Figure 2
AI summary
The disclosed subject matter generally relates to a method for detecting valve leakage of a least one valve at a cylinder intake manifold or exhaust manifold of a vehicle engine, the method comprising: acquiring a set of pressure data points indicative of the pressure in the cylinder intake manifold or exhaust manifold for crankshaft angular positions covering crankshaft angular rotation degrees such that each of the at least one valve has opened at least one time; and determining at least one test value based on the set of pressure data points, wherein a valve leakage is detected based on a comparison of the at least one test value to a threshold value.