Hydrocarbon Sensor Diagnostic Using EGR Valve Actuation
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Solution Overview
Problem
Existing systems for diagnosing hydrocarbon sensors in internal combustion engines lack efficient methods to determine sensor faults, particularly in relation to ambient air temperature and cylinder head temperature, which are crucial for regulatory compliance and engine operation.
Innovation Solution
A computer-programmed system that collects data from a hydrocarbon sensor mounted between an exhaust port and intake port of an engine, determining sensor faults based on collected data, ambient air temperature, and cylinder head temperature, while actuating the exhaust gas recirculation valve and fuel injector, and storing or transmitting fault codes accordingly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If sensor diagnosis is performed continuously during engine operation, then diagnostic accuracy is improved, but system complexity and energy consumption increase
Solution Approach 1:
The system performs sensor diagnosis during engine startup before normal operation begins. The ECU executes diagnostic routines that collect sensor data and determine fault conditions during the startup phase, eliminating the need for continuous diagnosis during operation. This preliminary action resolves the contradiction by achieving accurate diagnosis without requiring complex continuous monitoring systems.
2Loss of time
If sensor diagnosis is performed within a short time window during startup, then diagnostic timeliness is improved, but measurement accuracy may deteriorate due to transient conditions
Solution Approach 1:
The diagnostic system dynamically adjusts its measurement strategy based on engine startup phase. During the warm-up period, the ECU collects sensor data at multiple time points and uses dynamic threshold comparisons rather than static values. The system evaluates whether sensor readings are consistent with expected transient behavior at each startup stage, allowing accurate diagnosis within the time window despite changing conditions.
3Measurement precision
If environmental factors like temperature are considered in diagnosis, then diagnostic accuracy is improved, but processing complexity increases
Solution Approach 1:
The ECU incorporates environmental parameters such as ambient temperature and engine temperature into the diagnostic evaluation by adjusting fault thresholds dynamically. Instead of using fixed threshold values, the system modifies acceptable sensor ranges based on temperature conditions. For example, hydrocarbon sensor thresholds are adjusted according to ambient temperature to account for natural variations in sensor output, improving accuracy without requiring complex multi-parameter analysis.
Data Source
AI summary
A hydrocarbon sensor diagnosis system includes a computer programmed to collect data from a hydrocarbon sensor while an exhaust gas recirculation system is in an open state. The hydrocarbon sensor is mounted along an engine air intake between an exhaust port of the exhaust gas recirculation system and an intake port of a cylinder head. The computer is further programmed to determine whether a hydrocarbon sensor fault exists based at least on the collected data.