Engine Control Device Oxygen Storage Ratio Prediction
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Solution Overview
Problem
The increasing frequency of idling stop and fuel cut in internal combustion engines leads to inaccurate grasping of oxygen storage state and temperature in three-way catalysts, deteriorating catalyst purification efficiency and emission performance.
Innovation Solution
An internal combustion engine control device that includes a catalyst in the exhaust pipe, upstream and downstream exhaust gas sensors, an oxygen storage ratio calculation unit based on a catalytic reaction model, and a statistical model for predicting downstream exhaust gas concentration to calculate air-fuel ratio corrections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If idling stop and fuel cut operations are increased to reduce fuel consumption, then fuel economy is improved, but the oxygen storage state and temperature in the three-way catalyst cannot be accurately grasped, causing catalyst purification efficiency to deteriorate
Solution Approach 1:
The control device performs preliminary rich correction of the air-fuel ratio before the catalyst oxygen storage state reaches problematic levels. By detecting oxygen release from the catalyst and proactively adjusting the air-fuel ratio to rich, the system maintains optimal catalyst conditions during and after idling stop operations, preventing purification efficiency deterioration while enabling frequent fuel-cut operations
Solution Approach 2:
The system uses feedback from oxygen sensors (both upstream and downstream of the catalyst) to continuously monitor catalyst oxygen storage state and adjust air-fuel ratio control accordingly. This closed-loop control enables accurate grasping of catalyst state during idling stop operations and maintains optimal purification efficiency by dynamically correcting air-fuel ratio based on real-time catalyst conditions
2Measurement precision
If feedback correction is performed by detecting oxygen released on the downstream side of the three-way catalyst, then air-fuel ratio control is adjusted, but the oxygen storage state reaches the lower limit or upper limit value at the detection timing, causing catalyst purification efficiency to deteriorate
Solution Approach 1:
Instead of waiting for oxygen release detection to trigger correction, the system performs preliminary rich correction based on predicted catalyst state and operational conditions. The control device calculates appropriate rich correction amounts in advance and applies them before the catalyst oxygen storage state reaches extreme values, ensuring purification efficiency is maintained throughout the correction process
Solution Approach 2:
The system dynamically adjusts the timing and magnitude of air-fuel ratio correction based on real-time catalyst conditions, engine operating parameters, and predicted future states. Rather than using fixed threshold-based correction, the control continuously adapts correction strategies to maintain optimal catalyst oxygen storage state within the target range
3Productivity
If rich correction is performed based on fuel increase period according to estimated oxygen storage amount, then air-fuel ratio is adjusted, but catalyst temperature state and transient exhaust gas flow rate changes are not considered, causing inappropriate correction and emission performance deterioration
Solution Approach 1:
The control device incorporates multiple dynamic parameters including catalyst temperature estimates, exhaust gas flow rate changes, and engine operating conditions into the rich correction calculation. By considering these varying parameters, the system determines appropriate correction amounts that account for transient conditions, ensuring both rapid response and maintained emission performance during dynamic operation
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 solution maintains high catalyst purification efficiency and prevents emission performance deterioration by accurately managing oxygen storage and air-fuel ratios, considering catalyst temperature and transient exhaust gas flow changes.
Implementation Method 1
a catalytic reaction model having at least a detection value of the first exhaust gas sensor as an input... defined by a reaction rate between at least oxygen on the upstream side of the catalyst, carbon monoxide on the upstream side of the catalyst, and a metal carried in the catalyst
Data Source
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AI summary
To keep catalyst purification efficiency high and prevent deterioration of emission performance. Therefore, an internal combustion engine control device according to an aspect of the present invention includes: an oxygen storage ratio calculation unit that calculates an oxygen storage ratio of a catalyst based on a catalytic reaction model having at least a detection value of a first exhaust gas sensor disposed on an upstream side of the catalyst as an input; a statistical model calculation unit that predicts a catalyst downstream exhaust gas concentration using a statistical model having an oxygen storage ratio as an input and a catalyst downstream exhaust gas concentration as an output; and an air-fuel ratio correction amount calculation unit that calculates an air-fuel ratio correction amount of an air-fuel mixture of an internal combustion engine based on a future catalyst downstream exhaust gas concentration calculated by the statistical model calculation unit.