Engine Control Noise Filtering via Correlation Index
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Solution Overview
Problem
Noise superimposed on the output signal of an in-cylinder pressure sensor in internal combustion engines can lead to errors in calculating the specific ratio combustion point, affecting engine control accuracy, as existing technologies do not effectively detect and mitigate noise-induced errors in engine control systems.
Innovation Solution
A control device for internal combustion engines that includes an in-cylinder pressure sensor, a crank angle sensor, and an electronic control unit, which calculates the correlation index value between measured and reference data to detect noise and adjust engine control parameters, preventing noise-induced errors by reducing the reflection of noisy combustion cycle data.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If engine control is based on actually measured data of combustion mass ratio from in-cylinder pressure sensor, then combustion control accuracy is improved, but noise superimposition on sensor output signal introduces errors in specific ratio combustion point calculation
Solution Approach 1:
The patent introduces a correlation index as an intermediary parameter to assess the quality of combustion mass ratio data. This correlation index serves as a mediator between the raw sensor data and the control decisions, filtering out noise-induced errors before they affect engine control. The control unit uses this intermediary index to determine whether to trust and apply the measured combustion characteristics.
Solution Approach 2:
The patent implements a feedback mechanism where the control unit continuously monitors the correlation index of the combustion mass ratio data and adjusts engine control accordingly. When the correlation index indicates poor data quality (low correlation), the system feedbacks to prevent using erroneous combustion point data for control decisions, thereby maintaining control reliability despite noise in the sensor signal.
2Measurement precision
If noise detection and countermeasures are implemented, then engine control accuracy is maintained, but device complexity increases due to additional correlation index calculation and control logic
Solution Approach 1:
The system performs self-diagnosis through the correlation index calculation, automatically assessing the quality of its own measurement data without external intervention. The control unit uses the correlation index to self-regulate whether to apply combustion control based on the current data quality, eliminating the need for separate manual noise detection systems or complex external filtering hardware.
Data Source
AI summary
A control device for an internal combustion engine includes an in-cylinder pressure sensor, a crank angle sensor, and an electronic control unit. The electronic control unit is configured to calculate a correlation index value showing a degree of a correlation between a actually measured data of a combustion mass ratio and reference data of the combustion mass ratio based on an operating condition of the internal combustion engine. The electronic control unit is configured to, in a case where the correlation index value is lower than a determination value, prohibit the actually measured value of the specific ratio combustion point pertaining to a combustion cycle in which the correlation index value is calculated from being reflected in the engine control or reduce a degree of the reflection in the engine control compared to a case where the correlation index value is equal to or higher than the determination value.