Oxygen Sensor Control for Signal Lag Diagnosis
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Solution Overview
Problem
Current oxygen sensor control methods require time-consuming and costly exhaust gas modeling to diagnose sensor failures and do not effectively manage heating performance, leading to reduced sensor accuracy and inability to improve sensor performance post-diagnosis.
Innovation Solution
An apparatus and method for controlling an oxygen sensor that detects signal lag due to reduced responsiveness, stores occurrence factor information, increases heating in specific regions, and reconfirms sensor failure or releases detection based on heating quantity changes, using a ZrO2 oxygen sensor with a controller to manage heating and measure internal resistance and lambda voltage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If exhaust gas modeling is used for fault diagnosis, then diagnosis accuracy is improved, but operation time and cost increase significantly
Solution Approach 1:
The patent extracts the essential diagnostic information from the complex exhaust gas modeling process by focusing specifically on signal lag detection and heater performance assessment. Instead of performing complete exhaust gas modeling, the system isolates and monitors key parameters (signal responsiveness and heater current) that indicate sensor health, thereby achieving accurate diagnosis without the time-consuming full modeling process.
Solution Approach 2:
The system performs preliminary monitoring of signal lag and heater performance continuously during normal operation. By maintaining ready-to-use diagnostic data through continuous monitoring of the oxygen sensor signal responsiveness and heater current requirements, the system prepares diagnostic information in advance, eliminating the need for time-consuming analysis when fault diagnosis is actually needed.
2Measurement precision
If exhaust gas modeling is used for fault diagnosis, then diagnosis accuracy is improved, but operational cost increases
Solution Approach 1:
The patent extracts only the necessary diagnostic parameters (signal lag and heater performance) from the complex exhaust gas modeling process. By monitoring only these specific indicators through the existing controller and oxygen sensor, the system achieves reliable fault diagnosis without requiring expensive comprehensive exhaust gas analysis equipment or complex processing systems.
Solution Approach 2:
The oxygen sensor system performs self-diagnosis by monitoring its own signal responsiveness and heater current requirements. The controller detects signal lag and assesses heater performance using the sensor's inherent characteristics, eliminating the need for external diagnostic equipment or complex exhaust gas modeling systems, thereby reducing operational costs while maintaining diagnosis accuracy.
3Reliability
If heater current is increased to maintain sensor temperature, then sensor responsiveness is improved, but energy consumption increases
Solution Approach 1:
The patent implements dynamic heater control by continuously monitoring the oxygen sensor signal responsiveness and adjusting heater current accordingly. When signal lag is detected, the system increases heater current to restore proper sensor temperature and responsiveness. When the sensor functions normally, the heater current is reduced to minimal levels. This dynamic adjustment optimizes the balance between sensor reliability and energy consumption.
Solution Approach 2:
The system uses feedback from the oxygen sensor signal itself to control heater operation. The controller monitors signal lag and uses this feedback to adjust heater current in real-time. This closed-loop control ensures the heater operates only when necessary to maintain sensor responsiveness, avoiding continuous high energy consumption while ensuring sensor reliability when needed.
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 allows for efficient diagnosis and performance improvement of oxygen sensors without extensive exhaust gas modeling, confirming specific operation conditions and recovering sensor signal responsiveness, thereby reducing operational time and costs while determining sensor failures accurately.
Implementation Method 1
the ECM controls the heater installed inside the oxygen sensor according to the temperature of the exhaust gas to keep the temperature of the sensor constant
Implementation Method 2
a resistance value inside the oxygen sensor which reacts to an oxygen amount in the exhaust gas varies depending on a temperature of the sensor
Data Source
AI summary
An apparatus for controlling an oxygen sensor may include an oxygen sensor configured to measure the exhaust gas which is generated by the combustion of the engine to generate an oxygen signal, and a controller configured to detect, through the oxygen sensor, a lag of the oxygen signal having responsiveness which is reduced depending on an oxygen amount of the exhaust gas, store information on occurrence factors which cause the lag of the oxygen signal, and increase a current heating quantity of a corresponding specific region about the occurrence factors to reconfirm whether the oxygen signal lags and determine the oxygen sensor as a failure or release a failure detection for the oxygen sensor.