Engine Phase Difference Identification via Pressure Oscillation Analysis
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Solution Overview
Problem
Current methods for determining phase differences between piston strokes and valve lifts in internal combustion engines are limited in precision and accuracy, leading to suboptimal fuel charge and control parameters, affecting emissions, consumption, and performance due to manufacturing and assembly tolerances, as well as mechanical stress.
Innovation Solution
A method involving the measurement of dynamic pressure fluctuations in the intake air and exhaust gas tracts, using discrete Fourier transformation to determine phase angles and calculate phase differences between piston and valve lifts without additional sensors, allowing for precise identification of piston stroke, intake valve lift, and exhaust valve lift phase differences.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional methods are used to determine phase differences between piston strokes and valve lifts, then the system is simple to operate, but the measurement precision is insufficient leading to suboptimal fuel charge and control parameters
Solution Approach 1:
The system uses existing pressure sensors and crankshaft position sensors already present in the engine to measure phase differences. The control unit processes the signals from these existing sensors through Fourier transformation to extract phase information, eliminating the need for additional dedicated measurement sensors while achieving precise phase difference determination
Solution Approach 2:
The patent replaces complex mechanical measurement systems with signal processing methods. By using Fourier transformation on pressure signals and crankshaft position signals, the system converts mechanical/physical measurements into mathematical analysis, achieving high precision phase difference measurement through computational methods rather than additional mechanical sensors
2Ease of manufacture
If manufacturing and assembly tolerances are present, then the device is easier to manufacture, but the reliability of phase position determination deteriorates
Solution Approach 1:
The system continuously measures actual phase positions during engine operation using pressure sensors and crankshaft position sensors. The control unit processes these signals to determine actual phase differences between piston strokes and valve lifts, providing real-time feedback that compensates for manufacturing and assembly tolerances, ensuring reliable operation despite variations in component dimensions and assembly precision
Solution Approach 2:
The patent changes the approach from fixed predetermined phase positions to dynamically determined phase positions based on actual pressure fluctuations and crankshaft position. By using Fourier transformation to extract phase information from operational signals, the system adapts to actual engine conditions and compensates for parameter variations caused by manufacturing tolerances
3Power
If mechanical stress is present during operation, then the engine can operate under load, but the accuracy of phase difference determination deteriorates due to deformation
Solution Approach 1:
The system continuously monitors phase differences during engine operation under various load conditions using pressure sensors and crankshaft position sensors. The control unit processes these signals in real-time to determine actual phase positions, providing continuous feedback that compensates for deformations caused by mechanical stress, ensuring accurate phase difference determination throughout the entire operating range from idle to full power
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 phase positions and differences, optimizing gas exchange and control parameters, thereby improving engine performance, reducing emissions, and enhancing operational efficiency.
Implementation Method 1
a phase angle of more than two selected signal frequencies of the measured pressure oscillations in relation to a crankshaft phase angle signal is determined from the pressure oscillation signal with the aid of discrete Fourier transformation
Data Source
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AI summary
A method for the combined identification of a piston stroke phase difference, an inlet valve phase difference and an outlet valve phase difference of a cylinder of an internal combustion engine, wherein dynamic pressure oscillations, 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 the phase position of selected signal frequencies of the measured pressure oscillations, lines of equal phase positions are determined and, by projection and phase shifting, are brought to a common point of intersection, from which the inlet valve stroke phase difference and the outlet valve stroke phase difference and the piston stroke phase difference are determined. In this way, it is possible to realize particularly accurate identification of the control timings in a simple and inexpensive manner, whereby advantages can be achieved with regard to emissions, consumption, running smoothness and power, and an improvement in regulability and control of the engine can be achieved.