Fuel Pressure Sensor Stuck Detection in Internal Combustion Engine Control
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Solution Overview
Problem
Existing control devices for internal combustion engines fail to detect abnormalities in fuel pressure sensors early enough, leading to potential deviations in air-fuel ratios and inefficient stuck detection processes, especially in hybrid vehicles where engine operation is variable.
Innovation Solution
A control device that performs stuck detection of fuel pressure sensors by initially setting a high target pressure and then reducing it, allowing for early detection and preventing engine shutdown during the process to ensure reliable detection, even in hybrid vehicles with variable engine operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the fuel pressure sensor abnormality diagnosis is performed using the conventional method of increasing fuel pressure to relief valve opening pressure, then the diagnosis can be performed, but the stuck detection cannot be completed at an early stage and may be interrupted in hybrid vehicles with frequent engine shutdowns
Solution Approach 1:
The patent performs stuck detection by changing fuel pressure to a predetermined pressure before normal operation begins. This preliminary action ensures the fuel pressure sensor is verified to be functioning correctly before the engine enters normal operation, preventing undetected sensor failures from affecting subsequent air-fuel ratio control. The detection is completed in advance, avoiding interruptions that would occur if performed during normal operation in hybrid vehicles.
2Loss of energy
If the engine operation is allowed to proceed normally without preventing shutdown during detection, then fuel efficiency is improved through frequent shutdowns in hybrid vehicles, but the stuck detection process may be interrupted and fail to complete
Solution Approach 1:
The patent prevents engine shutdown during the stuck detection process by setting a flag that prohibits shutdown while detection is in progress. This preliminary protective action ensures the detection process completes successfully without interruption, even in hybrid vehicles that normally shut down the engine frequently for fuel efficiency. The protection is temporary and automatically removed after detection completes.
3Loss of time
If the fuel pressure is changed to a predetermined pressure for stuck detection, then early detection can be achieved, but the detection process requires preventing engine shutdown which may affect operational flexibility
Solution Approach 1:
The patent performs the stuck detection at a predetermined timing (e.g., at startup or before normal operation) when the engine state is stable and shutdown is not required. By completing the detection process in advance under controlled conditions, the system achieves early detection without compromising the engine's operational flexibility during normal operation. The shutdown prevention is temporary and only applies during the brief detection window.
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
Enables early completion of stuck detection, improving fuel efficiency and reliability by preventing interruptions during the detection process, especially in hybrid vehicles with frequent engine startups and shutdowns.
Implementation Method 1
a feed pump that pressurizes and supplies the fuel to the storage section
Implementation Method 2
a fuel pressure sensor that detects a pressure of the fuel stored in the storage section
Implementation Method 3
a port injection valve that injects fuel into an intake passage
Data Source
AI summary
An internal combustion engine includes a port injection valve and a feed pump that pressurizes the fuel. An engine ECU performs a stuck abnormality diagnosis of the fuel pressure sensor based on detection values of the fuel pressure sensor in first processing and second processing. The first processing includes setting a target pressure of the fuel in the storage section to a first pressure, and detecting a pressure of the fuel with the fuel pressure sensor. The second processing includes setting the target pressure of the fuel in a low-pressure delivery pipe to a second pressure lower than the first pressure, and detecting a pressure of the fuel. The engine ECU causes the first processing to be performed in response to a start signal that starts an internal combustion engine, and causes the second processing to be performed subsequent to the first processing.