Spark-Ignition Engine Ignition Timing Compensation for Knock Control
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Solution Overview
Problem
Existing control systems for internal combustion engines face excessive processing load due to frequent switching of ignition maps in response to crank striking sounds, which can lead to abnormal sound generation and inefficient fuel consumption.
Innovation Solution
A control apparatus that adjusts ignition timing based on detected engine rotation speed and load, using predetermined retard amounts to compensate ignition timing rather than switching maps, thereby suppressing abnormal sounds and reducing processing load.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If multiple ignition maps are switched in accordance with crank striking sound detection, then crank striking sound can be suppressed, but processing load becomes excessive
Solution Approach 1:
The patent extracts the essential control parameter (ignition timing) from the complex multi-map switching system. Instead of switching between multiple pre-defined ignition maps based on crank striking sound detection, the system calculates and adjusts only the ignition timing parameter directly, eliminating the need for multiple maps and reducing processing complexity while maintaining the ability to suppress crank striking sound
Solution Approach 2:
The patent changes the control approach from discrete map switching to continuous parameter adjustment. By calculating ignition timing based on detected crank striking sound characteristics and adjusting it accordingly, the system achieves adaptive control without the computational overhead of selecting from multiple pre-stored maps, thus reducing processing load while maintaining effectiveness in suppressing abnormal sounds
2Object-affected harmful factors
If ignition timing is controlled by switching multiple maps, then abnormal sound can be suppressed, but fuel consumption efficiency deteriorates
Solution Approach 1:
The patent implements continuous optimization of ignition timing parameters based on real-time engine operating conditions and detected abnormal sounds. By dynamically adjusting ignition timing rather than switching between fixed maps, the system maintains optimal combustion efficiency across varying load and speed conditions, thereby suppressing abnormal sounds while preventing fuel consumption deterioration
Solution Approach 2:
The patent transitions from static pre-defined ignition maps to dynamic real-time ignition timing control. The system continuously adapts ignition timing based on current engine state and detected crank striking sound characteristics, ensuring optimal performance across different operating conditions without the energy efficiency penalties associated with discrete map switching
Data Source
AI summary
Control apparatus for spark ignition type of internal combustion engine, includes: sensor detecting rotation speed and load of engine; and ECU controlling ignition timing of engine based on rotation speed and load and characteristic of reference ignition timing. ECU: calculates first retard amount by multiplying difference between octane number of fuel currently supplied to engine and reference octane number by predetermined retard amount; compensates knock ignition timing to be retarded by first retard amount; and calculates second retard amount based on predetermined retard amount and compensates reference ignition timing to be retarded by second retard amount when operation region of engine defined by rotation speed and load becomes either one of predetermined load region higher in load than optimum operation line in which net fuel consumption rate of engine is highest or maximum output region in which output of engine is maximized.