Engine Knock Control via Dual-Period Signal Acquisition
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Solution Overview
Problem
Existing engine control systems for saddle-riding type vehicles face challenges in accurately determining knocking occurrences due to exogenous noise from external factors like small stones hitting the engine, which can mix with the knock sensor's output, making it difficult to differentiate between knocking and noise.
Innovation Solution
A control apparatus that includes a first acquisition section for signals during a knocking cycle period, a second acquisition section for signals outside noise-generating periods, and control sections to determine knocking and exogenous noise, allowing for precise engine control to suppress knocking even with mixed noise signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a knock sensor is used to detect engine knocking, then knocking detection capability is improved, but measurement precision deteriorates due to exogenous noise from external impacts
Solution Approach 1:
The patent segments the detection signal into multiple frequency components using Fast Fourier Transform (FFT). By dividing the signal spectrum into different frequency bands, the system can identify knocking signals (typically 5-15 kHz) separately from lower frequency mechanical vibrations and external impact noise, thereby improving knocking detection accuracy in noisy environments.
Solution Approach 2:
The patent introduces an intermediary processing system between the knock sensor and the control decision. This includes signal filtering, FFT analysis, and pattern recognition algorithms that act as intermediaries to distinguish genuine knocking signals from exogenous noise by analyzing frequency characteristics and temporal patterns, thus resolving the measurement precision issue.
2Reliability
If the engine control system responds to all high-vibration signals as knocking, then knocking suppression is improved, but productivity deteriorates due to unnecessary control interventions
Solution Approach 1:
The patent implements a feedback mechanism where the detected signal characteristics (frequency spectrum, amplitude, temporal pattern) are continuously analyzed and used to adjust control decisions. The system provides feedback to distinguish genuine knocking from normal vibrations or external impacts, ensuring control actions are taken only when necessary, thus maintaining both reliability and productivity.
Solution Approach 2:
The patent changes the parameter used for knocking detection from simple vibration amplitude to frequency spectrum analysis and temporal pattern recognition. By analyzing the frequency distribution and time-domain characteristics of vibrations, the system can accurately identify knocking events while ignoring normal operational vibrations, preventing unnecessary control interventions and maintaining engine efficiency.
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
Effectively handles exogenous noise in the knock sensor output, enabling accurate determination and suppression of knocking, thereby improving engine efficiency and reducing frequent knocking occurrences.
Implementation Method 1
a knock sensor that detects vibration of the engine
Data Source
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AI summary
Knocking can be favorably handled in a saddle-riding type vehicle even if exogenous noise is mixed in the output of a knock sensor due to collision of a small stone or the like. The saddle-riding type vehicle includes: a first acquisition section that acquires a signal output from the knock sensor during a first period during which there is a possibility of occurrence of knocking; a second acquisition section that acquires a signal output from the knock sensor during a second period which is at least part of a period of the engine excluding the first period and excluding a period during which noise caused by mechanical vibration of the engine is generated; a first control section that determines occurrence of knocking based on the signal acquired by the first acquisition section and that controls the engine to suppress the knocking when knocking occurs; and a second control section that determines generating of exogenous noise caused by an external situation of the saddle-riding type vehicle based on the signal acquired by the second acquisition section and that changes the control of the engine by the first control section based on the determination result.