Engine Control Abnormality Detection via Ignition Timing Feedback
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing engine control devices fail to detect abnormalities when the target efficiency is unusually decreased, leading to excessive torque output, as the decrease in target efficiency and increase in air amount cancel each other out, preventing accurate detection of torque deviations.
Innovation Solution
An abnormality detection device that calculates a second target efficiency using the target ignition timing and a second target torque, which are then used to determine torque deviations, ensuring that a decrease in target efficiency is not canceled out by an increase in load factor, thereby detecting abnormalities more effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the target efficiency is unusually decreased and the increased air amount is used for monitoring, then the target torque for monitoring matches the target torque, but the abnormality cannot be detected because the decrease in target efficiency and increase in air amount cancel each other out
Solution Approach 1:
The patent introduces target ignition timing as an intermediary parameter to calculate a second target efficiency. This intermediary calculation path allows detection of abnormalities that are masked when using only the original target efficiency and increased air amount, as the ignition timing reflects the actual engine state more accurately
Solution Approach 2:
The patent performs an additional partial calculation of target efficiency through the ignition timing pathway, creating a redundant monitoring channel. This excessive action of calculating efficiency twice (original method + ignition timing method) ensures that at least one method will detect the abnormality even when the other fails
2Object-generated harmful factors
If the target ignition timing is retarded to prevent excessive torque, then the target efficiency decreases, but the abnormality detection is compromised because the decreased target efficiency masks the abnormality
Solution Approach 1:
The patent creates a feedback loop where target ignition timing is used to recalculate target efficiency, which then feeds back into the abnormality detection logic. This feedback mechanism allows the system to recognize when torque control actions (retardation) are masking the very abnormalities they are trying to prevent
Solution Approach 2:
The patent performs preliminary calculation of a second target efficiency using target ignition timing before final abnormality determination. This preliminary action through an alternative calculation path prepares the detection system to identify abnormalities even when primary efficiency measurements are compromised by control actions
Data Source
AI summary
An abnormality detection device is mounted on an engine control device that calculates a target load factor by using a target torque, converts the target load factor to a target throttle opening, calculates a target ignition timing by using a target efficiency, and controls an engine based on the target throttle opening and the target ignition timing. In the abnormality detection device, a target efficiency for monitoring is calculated by using the target ignition timing, a target torque for monitoring is calculated by using the target efficiency for monitoring and the target load factor, a torque deviation between the target torque for monitoring and the target torque is calculated, and the presence or absence of an abnormality is detected by using the torque deviation.