Engine Damage Diagnosis via Cylinder-Specific Pre-ignition Mapping
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Solution Overview
Problem
Current methods for diagnosing and protecting spark-ignition engines from sporadic pre-ignition phenomena at low engine speeds are inadequate, as they do not effectively detect damage and provide immediate protection, leading to potential engine failure and passenger discomfort.
Innovation Solution
A diagnostic method that estimates engine damage by mapping engine speed and air filling, using a damage counter for each cylinder, and implements adaptive load reduction or degraded mode operation based on predetermined damage thresholds to prevent engine failure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If fuel injection is cut off rapidly to eliminate pre-ignition bursts, then pre-ignition is eliminated immediately, but passenger comfort deteriorates and engine malfunction is perceived
Solution Approach 1:
The system performs preliminary damage estimation by mapping engine operating conditions (speed, air filling) to potential damage values before actual damage occurs. This allows proactive protection measures to be taken based on predicted damage accumulation rather than reacting to actual pre-ignition events, thereby avoiding abrupt fuel cutoff and maintaining passenger comfort.
2Reliability
If a slow counter-based load limitation is used to eliminate pre-ignition, then engine protection is achieved, but the response is delayed and not immediate
Solution Approach 1:
The patent implements preliminary damage estimation by calculating potential damage values based on current engine operating conditions (speed and air filling) before actual damage accumulates. This allows the system to take protective action in advance when damage thresholds are approached, rather than waiting for damage to occur and then responding slowly with counter-based limitations.
Solution Approach 2:
The system continuously monitors engine operating conditions and updates damage estimates in real-time based on feedback from sensors measuring engine speed and air filling. This closed-loop feedback mechanism enables immediate adjustment of protective measures based on current damage risk levels, achieving both engine protection and rapid response.
3Measurement precision
If existing diagnostic methods are used, then pre-ignition detection is attempted, but engine damage diagnosis and long-term protection are not provided
Solution Approach 1:
The patent segments the damage assessment into cylinder-specific damage values, allowing individual cylinder damage to be tracked and diagnosed separately. This segmentation enables precise identification of which cylinder is suffering damage from pre-ignition, providing detailed engine damage diagnosis rather than just detecting pre-ignition events.
Solution Approach 2:
The system adds a temporal dimension to damage detection by accumulating damage values over time and comparing them against thresholds. This transforms the detection from a single-event observation to a cumulative damage assessment over driving cycles, enabling long-term engine health monitoring and prediction of future failures.
Data Source
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AI summary
The invention relates to a method for diagnosing damage to a controlled-ignition engine of a motor vehicle, said damage being due to sporadic pre-ignition phenomena at low engine speeds. A pre-ignition phenomenon is detected (1) for one cylinder of the cylinders of the engine at a given instant, damage to the cylinder at this given instant is estimated (2) on the basis of a map of the engine speed and of the air filling of the cylinder, with allocation of a damage value of the cylinder at this given instant, the damage value at the given instant being added (5) to the damage values previously allocated for the same cylinder in order to provide a total damage value specific to the cylinder. Possible damage to the engine by pre-ignition phenomena is diagnosed on the basis of the damage value of the cylinder with the greatest damage.