Pre-ignition Detection Using Engine Speed Analysis
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Solution Overview
Problem
Existing methods for determining the pre-ignition state in internal combustion engines are complex and require additional sensors or circuits, making them inefficient for fast and simple detection.
Innovation Solution
The method utilizes engine speed values, specifically the engine speed curve and standard deviation, to determine the pre-ignition state without additional sensors or circuits, by interrupting ignition and evaluating engine speed reactions, and adjusting fuel supply accordingly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the spark plug current supply is measured and evaluated to determine pre-ignition state, then pre-ignition detection is achieved, but the electronic evaluation circuit becomes comparatively complex
Solution Approach 1:
The patent extracts the pre-ignition detection function from the complex electronic evaluation circuit and relocates it to the existing engine speed sensing system. By using the alternator's engine speed signal, the method eliminates the need for additional sensors or complex evaluation circuits at the spark plug, achieving simplified detection while maintaining accuracy.
Solution Approach 2:
The patent makes the existing engine speed sensing system serve dual purposes: traditional engine speed control and pre-ignition detection. The alternator's engine speed signal, already required for engine control, is now also utilized for detecting pre-ignition states, eliminating the need for separate detection hardware.
2Difficulty of detecting and measuring
If additional sensors or circuits are installed at the spark plug for pre-ignition detection, then detection capability is improved, but the device complexity and cost increase
Solution Approach 1:
The patent enables the existing engine speed sensing system to perform self-service by utilizing its own signal for both speed control and pre-ignition detection. The alternator's engine speed signal serves the dual function without requiring external assistance or additional components, achieving detection capability through the system's existing resources.
3Productivity
If engine speed curve analysis is used to determine pre-ignition state, then detection simplicity and speed are improved, but the evaluation method becomes more dependent on existing engine control systems
Solution Approach 1:
The patent performs preliminary analysis of the engine speed curve characteristics during normal engine operation, establishing baseline patterns before pre-ignition occurs. By pre-characterizing the engine speed curve under various operating conditions, the system can quickly identify deviations indicating pre-ignition without requiring complex real-time evaluation.
Data Source
AI summary
In a method for operating an internal combustion engine, wherein the internal combustion engine has a cylinder in which a combustion chamber is provided that is delimited by a reciprocating piston guided in the cylinder, wherein the piston is connected by a connecting rod to a crankshaft and wherein the internal combustion engine has a device for supplying fuel and a device for igniting the fuel/air mixture in the combustion chamber at least one engine speed value of the internal combustion engine is determined and evaluated. A pre-ignition state of the internal combustion engine is determined based on the result of the evaluation step.