Fuel Pressure Sensor Offset Diagnosis via Pulsation Filtering
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing fuel pressure sensor diagnosis methods fail to detect offset abnormalities, leading to erroneous diagnoses and undetected faults in fuel pressure sensors, as the deteriorating sensors' output signals deviate from normal patterns but not significantly enough to be recognized as abnormal.
Innovation Solution
A fuel-pressure-sensor diagnosis device that selects two fuel pressure sensors from a plurality, comparing their detected values to diagnose offset abnormalities by ensuring their pulsation values are within a specified range, allowing for accurate detection of deviations and faults through differential pressure analysis.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single fuel pressure sensor is used to detect fuel pressure, then the device complexity is reduced, but the measurement precision and reliability of the fuel pressure detection deteriorates due to inability to detect offset abnormalities
Solution Approach 1:
The patent applies local quality by providing multiple fuel pressure sensors at different locations (each cylinder or common rail) and using them for different diagnostic purposes. The first fuel pressure sensor detects fuel pressure for injection control, while the second fuel pressure sensor specifically monitors for offset abnormalities, allowing each sensor to have specialized functionality.
Solution Approach 2:
The patent uses the second fuel pressure sensor as an intermediary device to detect offset abnormalities. This additional sensor acts as a mediator that compares its readings with the first sensor's readings to identify deviations, thereby enabling detection of offset abnormalities without interfering with the primary injection control function.
2Reliability
If the diagnosis method relies on detecting changes in fuel pressure during fuel injection, then the diagnostic capability is improved for certain abnormalities, but offset abnormalities cannot be detected because the slope remains normal
Solution Approach 1:
The patent performs preliminary action by continuously monitoring fuel pressure with multiple sensors before abnormalities develop. The second fuel pressure sensor continuously compares its readings with the first sensor to detect offset abnormalities early, preventing false negatives and enabling early intervention before the abnormality affects fuel injection control.
Solution Approach 2:
The second fuel pressure sensor serves as an intermediary that specifically monitors for offset abnormalities by comparing its readings with the first sensor. This intermediary detection mechanism captures offset abnormalities that would otherwise be missed, as it detects deviations in pressure levels rather than relying solely on changes during fuel injection.
3Ease of operation
If a single fuel pressure sensor is used, then the ease of operation is improved, but the reliability of fuel injection control deteriorates due to undetected sensor faults
Solution Approach 1:
The system performs self-service by using the second fuel pressure sensor to automatically detect and report offset abnormalities in the first fuel pressure sensor. This self-diagnosis capability maintains reliability without requiring external intervention or complex manual monitoring, as the system monitors its own health status continuously.
Solution Approach 2:
The second fuel pressure sensor acts as an intermediary monitoring device that continuously compares pressure readings to detect abnormalities. This intermediary mechanism maintains the simplicity of operation while significantly improving reliability, as it automatically identifies sensor faults without complicating the fuel injection control system.
Data Source
AI summary
A fuel-pressure-sensor diagnosis device is applied to a fuel injection system having a plurality of fuel pressure sensors detecting a fuel pressure which is provided to a fuel injector of each cylinder, and a control portion controlling the fuel injectors by using a computed result which is computed based on a variation in the fuel pressure detected by the fuel pressure sensor due to a fuel injection. Two pressure sensors of which pulsation values of the detected fuel pressure are in a specified range are selected among the multiple fuel pressure sensors. For example, a pair “A” refers to the sensors #1 and #3, a pair “B” refers to the sensors #3 and #4, a pair “C” refers to the sensors #4 and #2, and a pair “D” refers to the sensors #2 and #1. An ECU diagnoses whether the selected sensors are faulty by comparing the detected values.