Combustion Noise Parameter Determination via Cylinder Force Segmentation
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Solution Overview
Problem
Current methods for representing combustion noise in automobile engine cylinders are inaccurate and incomplete as they only relate to the combustion process of combustible gas itself and do not consider the excitation of the cylinder over time.
Innovation Solution
A method and device that determine combustion noise parameters by acquiring a cylinder pressure sequence and calculating additional parameters such as top and side surface cylinder forces and their rise rates, which are then converted into frequency domain sequences for more accurate representation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional representation parameters (cylinder pressure, pressure rise rate) are used, then the measurement is simple, but the representation accuracy of combustion noise is insufficient
Solution Approach 1:
The patent segments the cylinder surface into multiple areas (top surface, side surfaces, bottom surface) and calculates force parameters for each segment separately. This segmentation allows the system to capture spatial distribution of combustion forces, improving noise representation accuracy while maintaining manageable calculation complexity through modular processing of each surface segment.
Solution Approach 2:
The patent transitions from traditional scalar pressure parameters to vector force parameters by introducing surface area dimensions. By calculating forces as F = P × S (pressure × surface area) for different cylinder surfaces, the method adds spatial dimensionality to the representation, enabling more accurate characterization of combustion noise excitation while systematically managing the increased computational requirements.
2Loss of information
If only combustion process parameters are considered, then the analysis is straightforward, but the excitation characteristics of cylinder are not captured
Solution Approach 1:
The patent merges combustion process parameters (pressure, temperature) with geometric parameters (surface areas of cylinder top, sides, bottom) to compute force parameters. This combination integrates the combustion process information with the cylinder structure information, capturing both the combustion characteristics and the resulting cylinder excitation without creating an overly complex separate measurement system.
Solution Approach 2:
The patent introduces force parameters as an intermediary between combustion pressure and cylinder excitation. Instead of directly measuring cylinder vibration or noise, the method uses force (F = P × S) as a intermediate physical quantity that bridges the combustion process and the resulting mechanical excitation, providing a computationally efficient way to represent noise characteristics.
Data Source
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AI summary
A method and a device for determining combustion noise parameters, comprising acquiring a cylinder pressure sequence which comprises cylinder pressures corresponding to different crank angles ϕ and corresponding moments tϕ; calculating a first parameter sequence according to the cylinder pressure sequence, wherein the first parameter sequence is a parameter sequence in a time domain, and the first parameter sequence comprises one or more of a top surface cylinder force sequence, a top surface cylinder force rise rate sequence, a side surface cylinder force sequence and a side surface cylinder force rise rate sequence; and determining a target parameter for representing combustion noise in the cylinder according to the first parameter sequence.