Ignition Advance Control for Knock Persistence
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Solution Overview
Problem
Current methods for correcting ignition advance in thermal engines to prevent knocking are either overly cautious and wasteful or efficient but risky, and do not allow for optimized adaptation, often resulting in unnecessary degradation of ignition advance and inefficient fuel consumption.
Innovation Solution
A method that applies a curative ignition advance degradation only after a second knock is detected within a predetermined time interval following the first knock, with a reduced degradation value applied if a second knock occurs during a shorter countdown interval, optimizing the correction to match the persistence of the knocking phenomenon.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If corrective ignition advance degradation is applied immediately upon detecting a knock, then engine protection is ensured, but fuel consumption increases and performance is reduced due to unnecessary corrections
Solution Approach 1:
The system performs preliminary monitoring of knock events within a time window before applying corrective action. A first countdown timer T1 is initiated upon detecting a first knock, and the system waits to see if a second knock occurs within this period before applying the full corrective degradation, thereby avoiding premature corrections for isolated knock events
Solution Approach 2:
The corrective action is made dynamic by adjusting the degradation value based on the knock persistence pattern. If a second knock is detected within the first time interval T1, a reduced degradation value is applied; if a third knock occurs within a second shorter interval T2, the full nominal degradation value is applied. This dynamic adjustment optimizes the balance between engine protection and fuel consumption
2Reliability
If ignition advance is reduced to stop knocking, then engine protection is achieved, but engine performance and fuel efficiency deteriorate
Solution Approach 1:
The system applies partial corrective action (reduced degradation value) when knock persistence is moderate, and only applies full excessive action (nominal degradation value) when knock persistence is severe. This selective application of partial or full correction maintains engine performance while providing necessary protection
Solution Approach 2:
The system changes the degradation parameter dynamically based on the observed knock pattern. The degradation value transitions between two states: a reduced value for moderate persistence and a nominal value for severe persistence, optimizing the trade-off between protection and performance
3Loss of energy
If adaptive correction with learning process is used, then fuel consumption is improved, but immediate engine protection is compromised
Solution Approach 1:
The system performs preliminary monitoring and evaluation of knock patterns before applying adaptive correction. By initiating countdown timers and detecting knock persistence patterns in advance, the system ensures that adaptive corrections are only applied when justified, maintaining both fuel efficiency and immediate engine protection
Solution Approach 2:
The system uses feedback from knock detection patterns to dynamically adjust the corrective action. The feedback mechanism monitors whether knocks occur within specific time intervals and adjusts the degradation value accordingly, ensuring both fuel efficiency and engine protection
Data Source
Figure 1
AI summary
The invention relates to a method for applying a curative degradation to the ignition advance (DegAV) by a predetermined nominal first value (Deg n) for a combustion engine after detecting a first instance of pinking (Cl1, Cl2, Cl5) during operation of the engine, characterized in that the application of the curative degradation to the ignition advance (DegAV) is suspended for as long as a second instance of pinking (Cl3) has not been detected within a first predetermined time interval (T1s) beginning with the detection of the first instance of pinking (Cl1, Cl2, Cl5).