Alcohol Concentration Estimation in Engine Fuel Mixtures
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Solution Overview
Problem
Existing methods for estimating alcohol concentration in alcohol fuel mixtures for internal combustion engines are inefficient and inaccurate, particularly due to high processing burdens on the engine control unit (ECU) and the unreliable nature of fuel-air ratio sensors, especially for ethanol fuel mixtures.
Innovation Solution
A method that controls the internal combustion engine in a stoichiometric condition using a pressure sensor and oxygen sensor, eliminating the need for heat release per unit fuel mass calculations and fuel-air ratio sensor outputs, by determining the alcohol concentration based on pre-stored relations between pressure parameters and alcohol concentration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If heat release per unit fuel mass calculation is used to determine alcohol concentration, then alcohol concentration can be determined in principle, but significant processing load is produced on the ECU
Solution Approach 1:
The patent extracts the alcohol concentration determination from the complex heat release calculation process. Instead of calculating heat release per unit fuel mass which requires multiple sensor inputs and complex computations, the invention uses a simplified approach based on exhaust gas oxygen concentration measurements alone, removing the computational burden while retaining the ability to determine alcohol concentration
Solution Approach 2:
The patent replaces the mechanical/computational system of heat release calculation with a chemical sensing approach. By using the oxygen sensor to measure exhaust gas composition and inferring alcohol concentration from oxygen consumption patterns during combustion, the system substitutes complex mathematical processing with direct chemical measurement and interpretation
2Measurement precision
If F/A sensor is used to measure fuel-air ratio for alcohol concentration determination, then alcohol concentration can be detected, but the sensor is inaccurate and difficult to impossible for ethanol fuel mixtures
Solution Approach 1:
The patent introduces exhaust gas oxygen concentration as an intermediary measurement. Instead of directly measuring fuel-air ratio with an unreliable F/A sensor, the system measures oxygen concentration in the exhaust gas, which serves as an indirect but reliable indicator of combustion characteristics and thus alcohol concentration in the fuel mixture
Solution Approach 2:
The patent changes the measurement parameter from fuel-air ratio (which is difficult to measure accurately for alcohol mixtures) to exhaust gas oxygen concentration (which can be measured reliably). By monitoring how oxygen is consumed during combustion of different alcohol concentrations, the system transforms an unmeasurable parameter into a measurable one
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 approach reduces processing burdens on the ECU and provides accurate alcohol concentration estimation in alcohol fuel mixtures, improving engine control and reducing emissions, without relying on inaccurate fuel-air ratio sensors.
Implementation Method 1
determining a first parameter on the basis of a signal from a pressure sensor sensing the pressure inside a combustion chamber
Implementation Method 2
determining whether the internal combustion engine is controlled in the stoichiometric condition based on a signal from an oxygen sensor sensing an oxygen concentration in combusted gas
Implementation Method 3
an internal combustion engine supplied with the alcohol fuel mixture
Data Source
Figure 1
Figure 2A~2B
Figure 3
AI summary
The present invention relates to a method and an apparatus for estimating an alcohol concentration in an alcohol fuel mixture supplied to an internal combustion engine, wherein the operation of the internal combustion engine supplied with the alcohol fuel mixture is operated in a stoichiometric condition, a first parameter is determined on the basis of a signal from a pressure sensor sensing the pressure inside a combustion chamber of the internal combustion engine being controlled in the stoichiometric condition, and the alcohol concentration of the alcohol fuel mixture is determined on the basis of the determined first parameter and a relation between the first parameter and the alcohol concentration of the alcohol fuel mixture.