Engine Knock Control Filter Adjustment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing internal combustion engine control systems face erroneous knock determination due to filtering operation delays when the engine transitions from a non-combustion state to a combustion state or when fuel cutoff control is cancelled, leading to a narrowed operation range of the knock suppression function.
Innovation Solution
An internal combustion engine control apparatus that includes a knock sensor, crank angle sensor, and units for calculating characteristic values, background levels, and standard deviations, with a filter coefficient changing mechanism to adjust filtering effects based on the engine's operation status, ensuring accurate knock determination without narrowing the knock suppression function's operation range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a strong filtering operation is used to calculate background level and standard deviation, then measurement precision of knock detection is improved, but the operation range of knock suppression function is narrowed due to tracking delay during engine state transitions
Solution Approach 1:
The patent applies dynamics by making the filter coefficient adjustable rather than fixed. The control apparatus changes the filter coefficient based on engine operation status (e.g., during starting, fuel cutoff, or other transient states), allowing the system to adapt between strong filtering for precision and weak filtering for responsiveness during transitions.
Solution Approach 2:
The patent changes the parameter of filter coefficient dynamically. By modifying this key parameter according to engine state, the system resolves the contradiction between maintaining high measurement precision through strong filtering and ensuring broad operation range through responsive tracking during transient conditions.
2Productivity
If the knock suppression function is activated immediately during engine starting, then productivity is improved, but reliability deteriorates due to erroneous knock determination from tracking delay
Solution Approach 1:
The patent applies preliminary action by detecting engine starting conditions before activating knock suppression. The control apparatus identifies transient states (like starting, fuel cutoff, or other transient states) in advance and temporarily suspends knock determination during these periods, preventing erroneous decisions while maintaining readiness to respond immediately when conditions stabilize.
Solution Approach 2:
The patent uses dynamics by making the filter coefficient adjustable rather than fixed. The control apparatus changes the filter coefficient based on engine operation status (e.g., during starting, fuel cutoff, or other transient states), allowing the system to adapt between strong filtering for precision and weak filtering for responsiveness during transitions.
3Productivity
If fuel cutoff control is cancelled immediately, then productivity is improved, but reliability deteriorates due to erroneous knock determination from vibration level changes
Solution Approach 1:
The patent applies preliminary action by detecting engine starting conditions before activating knock suppression. The control apparatus identifies transient states (like starting, fuel cutoff, or other transient states) in advance and temporarily suspends knock determination during these periods, preventing erroneous decisions while maintaining readiness to respond immediately when conditions stabilize.
Solution Approach 2:
The patent uses feedback by continuously monitoring engine operation status to determine when to activate or suspend knock suppression. The system receives feedback about transient conditions (from sensors detecting engine state) and adjusts knock determination accordingly, ensuring reliability while maintaining productivity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The system effectively suppresses erroneous knock determination by adjusting filter coefficients to track changes in vibration levels, maintaining the operation range of the knock suppression function during engine state transitions and fuel cutoff control changes.
Implementation Method 1
a knock sensor that detects a vibration produced in an internal combustion engine
Implementation Method 2
a vibration of an internal combustion engine detected by a knock sensor is processed through a band-pass filter or the like so that only vibration components of specific frequencies are extracted
Data Source
AI summary
There are provided a combustion start determination unit that determines whether or not the inner-cylinder state of an internal combustion engine has changed from a non-combustion state to a combustion state; and a filter coefficient changing demand unit that outputs a filter coefficient changing demand until a predetermined filter coefficient changing period elapses from the time instant when the combustion start determination unit determines that the inner-cylinder state of the internal combustion engine has changed from the non-combustion state to the combustion state to the time instant. Based on the filter coefficient changing demand, at least one of a background level calculation unit and a standard deviation calculation unit changes the value of a filter coefficient utilized in a filtering operation to the one with which a filtering effect is weakened.