Ambient Pressure Detection in Internal Combustion Engine Intake
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for determining ambient pressure in internal combustion engines, particularly in pressure-controlled systems, are imprecise due to manufacturing tolerances and fail to account for residual pressure differences during full-load operations, especially when the throttle flap is closed or in overrun modes.
Innovation Solution
A method that uses a pressure sensor in the intake pipe to determine ambient pressure by measuring air cleaner pressure and intake pipe pressure, with the throttle flap opened wide enough to minimize pressure drop, and adjusts the camshaft to maintain a constant engine state, allowing for precise ambient pressure calculation across various operating modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the throttle flap is opened wide to minimize pressure drop for accurate ambient pressure measurement, then measurement precision is improved, but the engine operating state changes undesirably (torque increases in part-load, braking effect reduces in overrun mode)
Solution Approach 1:
The camshaft is adjusted in advance to compensate for the expected operating state changes caused by dethrottling. By pre-adjusting the camshaft position before or during the dethrottling process, the system counteracts the undesired effects on torque and braking efficiency, allowing the throttle flap to be opened wide for accurate pressure measurement without significantly impacting engine performance
Solution Approach 2:
The system changes the camshaft position parameter to compensate for the dethrottling effect. By adjusting the camshaft to different positions depending on the operating mode (part-load, full-load, or overrun mode), the system maintains engine performance while enabling the throttle flap to be opened wide for accurate ambient pressure measurement
2Ease of operation
If the throttle flap is kept closed to maintain engine performance, then ease of operation is preserved, but measurement precision deteriorates due to residual pressure differences
Solution Approach 1:
The system performs a preliminary camshaft adjustment before attempting to measure ambient pressure. This preliminary action prepares the engine for the upcoming dethrottling by positioning the camshaft to minimize performance impact, enabling the subsequent wide opening of the throttle flap for accurate pressure measurement while maintaining operational stability
3Measurement precision
If dethrottling is performed to enable pressure measurement, then measurement precision is improved, but productivity decreases due to changes in engine torque and braking effect
Solution Approach 1:
The system uses feedback from the operating state detection to dynamically adjust the camshaft position. By continuously monitoring the engine mode (part-load, full-load, or overrun) and adjusting the camshaft accordingly, the system ensures that dethrottling for pressure measurement does not significantly impact torque production or braking efficiency, thereby maintaining productivity
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 provides a more accurate and precise determination of ambient pressure, minimizing the impact of dethrottling effects on engine operation, maintaining torque and braking efficiency, and enabling rapid detection without significant changes in engine state.
Implementation Method 1
detecting an intake pipe pressure through the pressure sensor in the intake pipe and determining the ambient pressure from the total of the air cleaner pressure and of the intake pipe pressure
Data Source
AI summary
There is described a method for detecting the ambient pressure by a pressure sensor in the intake pipe of an internal combustion engine. A throttle flap is opened so that the pressure drop via the throttle flap can be neglected. The dethrottling of the internal combustion engine is compensated by the appropriate adjustment of the cam shaft in accordance with the operating state of the internal combustion engine, so that the measuring method is not being felt by the driver.