Valve Phase Identification via Intake Pressure Oscillations
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Solution Overview
Problem
Current methods for determining phase differences in intake and exhaust valve lifts in internal combustion engines are limited in precision and can't account for all manufacturing and assembly tolerances, leading to suboptimal fuel charge and control parameters, affecting emissions, consumption, and performance.
Innovation Solution
A method using dynamic pressure fluctuations in the intake air and exhaust gas to generate pressure oscillation signals, which are analyzed via discrete Fourier transformation to determine the intake and exhaust valve lift phase differences without additional sensors, allowing for precise calculation of gas exchange and adjustment of control parameters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If current methods for determining phase differences are used, then the measurement can be performed with existing hardware, but the measurement precision is insufficient due to manufacturing and assembly tolerances
Solution Approach 1:
The patent replaces mechanical measurement methods (direct physical measurement of valve positions) with an acoustic field-based method. Pressure oscillations in the intake air are measured and analyzed to determine valve lift phase differences, substituting mechanical sensing with acoustic sensing and signal processing.
Solution Approach 2:
The patent introduces pressure oscillations in the intake air as an intermediary medium to indirectly measure valve lift phase differences. Instead of directly measuring valve positions, the method uses the acoustic signature of the intake air pressure oscillations, which are influenced by valve timing, as a mediator to infer the phase differences.
2Measurement precision
If additional sensors are added to improve measurement accuracy, then the measurement precision improves, but the hardware cost and device complexity increase
Solution Approach 1:
The patent makes the existing intake air pressure measurement system multi-functional. The same pressure sensor and measurement infrastructure used for other engine control purposes are also utilized to determine valve lift phase differences, eliminating the need for additional dedicated sensors while achieving precise measurement.
Solution Approach 2:
The patent enables the existing measurement system to serve itself by extracting additional information (valve lift phase differences) from the pressure oscillation data already being collected for other control functions. The system uses its own existing data infrastructure to achieve enhanced measurement capabilities without external additions.
3Manufacturing precision
If manufacturing and assembly tolerances are reduced to improve precision, then the measurement precision improves, but the manufacturing cost and complexity increase
Solution Approach 1:
The patent implements a feedback mechanism where the measured valve lift phase differences are used to adjust control parameters and compensate for manufacturing tolerances. The system continuously monitors pressure oscillations, determines actual valve timing deviations, and uses this information to optimize fuel charge and control parameters, closing the loop between measurement and control.
Solution Approach 2:
The patent changes the approach from fixing manufacturing precision to dynamically adjusting operational parameters. Instead of requiring tight manufacturing tolerances, the system measures the actual valve timing deviations and compensates by adjusting fuel injection timing, air charge calculations, and other control parameters to achieve optimal performance despite manufacturing variations.
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
This method enables accurate determination of valve lift phase differences, optimizing combustion processes, reducing fuel consumption, and lowering emissions by integrating the analysis into existing engine control units without additional hardware costs.
Implementation Method 1
dynamic pressure oscillations of the intake air in the air intake tract... are measured during operation, and from this, a corresponding pressure oscillation signal is generated
Implementation Method 2
From the pressure oscillation signal, the amplitudes of selected signal frequencies of the measured pressure oscillations are determined with respect to the crankshaft phase angle signal using discrete Fourier transforms
Data Source
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AI summary
The invention relates to a method for the combined identification of an inlet valve stroke phase difference and an outlet valve stroke phase difference of a cylinder of an internal combustion engine, wherein dynamic pressure oscillations, which are assignable to the cylinder, of the intake air in the air intake tract and/or of the exhaust gas in the exhaust gas outlet tract are measured during operation, and wherein, on the basis of amplitudes of selected signal frequencies of the measured pressure oscillations, lines of equal phase positions are determined and, by projection, are brought to a common point of intersection, from which the inlet valve stroke phase difference and the outlet valve stroke phase difference are determined. In this way, it is possible to carry out a particularly accurate identification of the valve control times in a simple and cost-effective manner, whereby advantages with regard to emissions, consumption, running smoothness and power as well as an improvement in controllability and control of the engine can be achieved.