Internal Combustion Engine Knock Detection via Dynamic Reference Level
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Solution Overview
Problem
Existing methods for controlling internal combustion engine combustion, such as those using structure-borne noise sensors, struggle to quickly adapt to changes in operating conditions, leading to delayed detection of irregular combustions like engine knock, premature ignition, or surface ignition, which can result in engine damage.
Innovation Solution
Implementing an accelerated averaging method for updating the reference level by increasing the weighting factor F after an irregular combustion event, allowing for quicker adaptation to new operating conditions and improved detection of irregularities through a weighted sum of previous and current intensity measurements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a moving average calculation is used to produce the reference value from measured values of preceding combustion processes, then the detection system is stable and reliable, but the reference level adapts slowly to changes in operating conditions, delaying detection of irregular combustions
Solution Approach 1:
The patent applies dynamics by making the averaging factor F variable rather than constant. The factor F is adapted dynamically based on operating conditions and detection states, allowing the system to switch between stable reference level maintenance (small F) and rapid adaptation (large F) modes, thus resolving the contradiction between reliability and adaptation speed
Solution Approach 2:
The patent changes the parameter F (averaging factor) based on different operating conditions and detection states. By adjusting F within the range (0, 1), the system can control the weight given to new measurements versus historical data, enabling rapid adaptation when needed while maintaining stability during normal operation
2Speed
If the averaging factor F is increased to accelerate adaptation to new operating conditions, then the reference level updates faster, but the system becomes more sensitive to transient fluctuations and may produce false detections
Solution Approach 1:
The system dynamically adjusts the averaging factor F based on the detection state and operating conditions. When irregular combustions are detected, F is increased to accelerate reference level adaptation. When no irregularities are present, F returns to normal values to maintain detection accuracy and avoid false positives, thus resolving the contradiction between update speed and reliability
3Measurement precision
If the reference level is updated slowly to avoid false detections during normal operation, then detection accuracy is maintained, but the system cannot quickly detect irregular combustions after operating condition changes
Solution Approach 1:
The system prepares for rapid detection by monitoring detection states and operating conditions continuously. When an irregular combustion is detected or operating conditions change significantly, the system preemptively increases the averaging factor F to accelerate reference level adaptation, reducing detection delay while maintaining precision through conditional adjustment rather than continuous high sensitivity
Data Source
AI summary
A method and a device for controlling a combustion of an internal combustion engine are provided, including an arrangement, which generates a signal for the intensity of the combustion in a combustion chamber of the internal combustion engine from a sensor signal of the internal combustion engine. The intensity is compared to a reference level, which was formed from intensities of preceding combustions in the combustion chamber by moving average calculation. An irregular combustion is detected if the intensity exceeds the reference level in a predetermined manner, and then at least one operating parameter of the internal combustion engine is shifted in the direction of an avoidance of the irregular combustion. Following an irregular combustion, the averaging for forming the reference level is accelerated for a specified duration.