Engine Controller Exhaust Purification Detachment Detection
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Solution Overview
Problem
Existing controllers for internal combustion engines face challenges in accurately determining if an exhaust purification device, such as a particulate matter filter, has been removed from the exhaust passage, leading to potential inefficiencies in engine operation and emissions control.
Innovation Solution
A controller with processing circuitry that calculates temperature change amounts on both sides of the exhaust purification device during a fuel cutoff operation and determines if the deviation between these changes is within a threshold, indicating the device's attached or detached state, while interrupting the process if the upstream temperature increases within a specified period.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the controller continuously monitors temperature changes to detect filter removal, then detection accuracy improves, but false anomalies may occur due to temporary temperature increases
Solution Approach 1:
The determination process is designed to be dynamic by interrupting based on real-time temperature trends. When the upstream temperature increases during the determination period, the process is automatically interrupted, allowing the system to adapt to changing thermal conditions and avoid false detections while maintaining detection accuracy during stable monitoring conditions
Solution Approach 2:
The system changes the operational state of the determination process based on temperature parameters. By monitoring whether upstream temperature increases during the determination period and interrupting accordingly, the system adjusts its detection behavior dynamically, preventing false anomalies caused by temporary temperature fluctuations while maintaining sensitivity to actual filter removal events
2Difficulty of detecting and measuring
If the controller uses temperature change comparison to determine filter status, then detection capability is achieved, but the process may be affected by transient temperature increases
Solution Approach 1:
The system takes preliminary anti-action by interrupting the determination process when upstream temperature increases are detected. This preemptive measure prevents transient temperature increases from causing incorrect detection results, thereby maintaining the reliability of temperature-based filter status detection
Solution Approach 2:
The system uses feedback from upstream temperature monitoring to control the determination process. When temperature increases during the determination period, the feedback triggers an interruption, creating a closed-loop control mechanism that enhances detection precision by eliminating interference from transient thermal events
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 enhances the accuracy of anomaly detection for the exhaust purification device, ensuring proper engine operation and emissions control by differentiating between attached and detached states based on temperature changes during the fuel cutoff operation.
Implementation Method 1
The heat of the exhaust gas conducted into the exhaust purification device is consumed by heat exchange with the exhaust purification device. As a result, there is a difference between a change in an exhaust gas temperature on the upstream side of the exhaust purification device and a change in the exhaust gas temperature on the downstream side of the exhaust purification device.
Data Source
AI summary
A controller for an internal combustion engine is configured to execute a determination process that determines that a deviation between a first change amount and a second change amount during a fuel cutoff operation is less than or equal to a threshold, and an anomaly diagnosing process that determines that an exhaust purification device is in a detached state when the determination process determines that the deviation is less than or equal to the threshold. The first change amount and the second change amount are change amounts per unit time of the temperature of exhaust gas on the upstream side and the downstream side of the exhaust purification device, respectively. The controller is configured to interrupt the determination process when the upstream-side temperature increases within a determination period.