Dynamic Mass Flow Filter Adaptation in Internal Combustion Engines
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current mass flow measurement techniques in internal combustion engines face challenges due to high pressure and flow fluctuations, rapid temperature changes, and composition variations, particularly at low speeds and high loads, leading to poor signal quality and accuracy in exhaust gas recirculation measurements.
Innovation Solution
A method that dynamically adapts filter parameters based on real-time engine status data transmitted by the engine control system, using a combination of sensors for differential pressure, absolute pressure, temperature, humidity, and gas composition, and optionally calculating gas composition from a model, to optimize filtering and ensure high accuracy and stability of mass flow signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If fixed filter parameters are used for mass flow measurement, then device complexity is reduced, but measurement precision deteriorates under varying engine conditions
Solution Approach 1:
The filter parameters are made dynamic rather than fixed. The evaluation unit continuously adapts filter parameters based on current engine operating conditions (load, speed, temperature) to maintain optimal measurement precision across varying operational states. This resolves the contradiction by allowing the system to switch from simple fixed filtering to adaptive dynamic filtering only when measurement precision requirements demand it.
Solution Approach 2:
The system changes filter parameters (cutoff frequencies, filter orders) based on measured operating conditions. When engine load or speed changes significantly, the evaluation unit adjusts filter parameters to match current pulsation characteristics, thereby maintaining measurement accuracy without requiring permanently complex filtering infrastructure.
2Measurement precision
If self-adaptive filtering is implemented to improve measurement accuracy, then measurement precision improves, but response time deteriorates due to parameter analysis delays
Solution Approach 1:
The evaluation unit continuously monitors engine operating parameters (load, speed, temperature) and prepares filter parameter adjustments in advance. When significant changes in engine operation are detected, the filter parameters are pre-adapted to anticipated pulsation conditions, reducing the actual response delay when measurement precision becomes critical.
Solution Approach 2:
The system implements continuous feedback loops where measured mass flow signals and engine operating conditions are constantly analyzed. The evaluation unit uses this feedback to dynamically adjust filter parameters in real-time, ensuring that adaptation delays are minimized by responding to actual measured conditions rather than waiting for predetermined intervals.
3Stability of the object's composition
If heavy filtering is applied to reduce pulsations, then stability improves, but signal dynamics deteriorate
Solution Approach 1:
Different filtering strengths are applied to different components of the measurement signal based on local signal characteristics. The evaluation unit analyzes the mass flow signal to identify pulsation components and applies targeted filtering only to specific frequency ranges or signal portions, preserving important dynamic information while removing harmful noise and pulsations.
Solution Approach 2:
The filter characteristics (cutoff frequencies, filter orders) are dynamically adjusted based on current engine operating conditions and signal characteristics. During transient operations where signal dynamics are critical, filtering is reduced to preserve response speed. During steady-state operations where stability is more important, stronger filtering is applied to suppress pulsations.
Data Source
AI summary
The invention relates to a method for determining the mass flow in an internal combustion engine by the pressure differential method, wherein, to calculate a mass flow signal, a mass flow meter measures a differential pressure (dp), an absolute pressure (pabs) and the temperature (temp) of the mass flow by means of sensors, the mass flow signal is filtered by an evaluation unit of the mass flow meter, and the filtered mass flow signal is sent to the engine control unit. The filter parameters are adapted by the evaluation unit according to the measurement situation: in a first measurement situation the filter parameters are set on the basis of an analysis of pulsations of the current measured values, and in a second measurement situation the filter parameters are set on the basis of state data of the internal combustion engine transmitted from the engine control unit.