Valve Phase Identification via Intake Pressure Fourier Analysis
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Solution Overview
Problem
Current methods for determining phase differences in the lift of intake and exhaust valves in internal combustion engines are limited in precision and accuracy, leading to suboptimal fuel charge and control parameters, affecting emissions, consumption, performance, and smooth running due to manufacturing tolerances and mechanical deviations.
Innovation Solution
A method involving the measurement of dynamic pressure fluctuations in the air intake tract using discrete Fourier transformation to determine the phase positions and amplitudes of selected signal frequencies, allowing for precise identification of intake and exhaust valve lift phase differences without additional sensors, and using algebraic model functions to adjust control parameters for optimal engine operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If current methods for determining phase differences are used, then device complexity is reduced, but measurement precision deteriorates
Solution Approach 1:
The system uses existing pressure sensors in the air intake tract to measure dynamic pressure fluctuations, and the engine control unit itself performs the Fourier transformation and phase difference calculation. No additional external measurement devices are required, as the existing system components serve the dual purpose of their original function plus phase difference measurement.
Solution Approach 2:
The patent replaces complex mechanical measurement systems with signal processing methods. By using discrete Fourier transformation on pressure signals already present in the system, the phase differences are determined through mathematical analysis rather than additional mechanical sensors or measurement apparatus.
2Reliability
If manufacturing tolerances and mechanical deviations are not compensated, then device complexity is reduced, but reliability deteriorates
Solution Approach 1:
The system continuously measures the actual phase differences during engine operation using pressure signal analysis and feeds this information back to the control unit. The control parameters are then adjusted based on the measured deviations from ideal phase relationships, creating a closed-loop control system that compensates for manufacturing tolerances and mechanical wear.
Solution Approach 2:
The patent dynamically adjusts control parameters such as fuel injection timing and amount based on the measured phase differences. By changing these operational parameters in response to actual measured conditions, the system compensates for fixed manufacturing tolerances and mechanical deviations, maintaining optimal engine performance and reliability.
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 high-accuracy determination of valve lift positions relative to the crankshaft phase angle, improving gas exchange processes and allowing for precise adjustment of control parameters, thereby reducing fuel consumption and emissions.
Implementation Method 1
the phase position and the amplitude of at least one selected signal frequency of the measured pressure oscillations in relation to the crankshaft phase angle signal are determined from the pressure oscillation signal with the aid of discrete Fourier transformation
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, said method being based on the determination of the phase position and the amplitude of a selected signal frequency of the pressure oscillations with regard to a phase angle signal of the crankshaft resulting from dynamic pressure oscillations of the intake air in the air intake tract, which are assignable to the respective cylinder. The inlet valve stroke phase difference and the outlet valve stroke phase difference are then determined on the basis of these phase positions and amplitudes with the aid of lines of equal phase position and lines of equal amplitude. In this way, it is possible to carry out a particularly accurate identification of the 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.