Unified Engine Control Device for Catalyst Temperature Estimation
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Solution Overview
Problem
Existing exhaust gas purification systems require different control devices based on the presence or absence of an oxidation catalyst, complicating catalyst temperature estimation and increasing manufacturing costs.
Innovation Solution
A control device that includes means for estimating catalyst temperatures in both NOx-occlusion-reduction-type and oxidation catalysts, using stored emission data to estimate heat generation and temperature, and switching between estimation processes based on the presence of an oxidation catalyst, allowing for unified application across systems with or without the oxidation catalyst.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If different control devices are manufactured for systems with and without oxidation catalyst, then catalyst temperature estimation can be tailored to each configuration, but manufacturing cost increases and device complexity increases
Solution Approach 1:
The control device is designed with a unified structure that can function for both systems with and without oxidation catalyst. The ECU includes a determination unit that identifies whether an oxidation catalyst is present, and based on this determination, selectively executes different temperature estimation processes (first process for NOx catalyst only, or second process for both catalysts), allowing a single device to adapt to multiple configurations without requiring separate manufacturing variants.
2Device complexity
If a unified control device is used for both systems with and without oxidation catalyst, then manufacturing cost decreases and device complexity decreases, but catalyst temperature estimation accuracy may be compromised
Solution Approach 1:
The control device employs dynamic adaptation by determining the actual catalyst configuration at runtime and switching between different temperature estimation processes accordingly. The ECU includes a determination unit that identifies whether an oxidation catalyst is present, and based on this determination, selectively executes the first temperature estimation process (for systems without oxidation catalyst) or the second temperature estimation process (for systems with oxidation catalyst), ensuring accurate temperature estimation adapted to the specific system configuration.
Solution Approach 2:
The control device changes operational parameters based on the detected catalyst configuration. When an oxidation catalyst is detected, the system switches to a different temperature estimation algorithm that accounts for the additional heat generation from the oxidation catalyst. This parameter change in the estimation process maintains accuracy across different hardware configurations without requiring different physical devices.
3Reliability
If temperature estimation is performed for both catalysts simultaneously, then comprehensive temperature monitoring is achieved, but calculation complexity and processing time increase
Solution Approach 1:
The control device performs temperature estimation for only the necessary catalysts based on the determined configuration. If no oxidation catalyst is present, the system performs temperature estimation solely for the NOx catalyst using the first process, avoiding unnecessary calculations. If an oxidation catalyst is present, the second process estimates temperatures for both catalysts. This selective approach ensures comprehensive monitoring of relevant components while minimizing processing time by avoiding excessive calculations.
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
Improves catalyst temperature estimation accuracy and reduces manufacturing costs by enabling a single control device to handle both configurations effectively.
Implementation Method 1
the NOx-occlusion-reduction-type catalyst reduces and purifies NOx (nitrogen compound) in the exhaust gas emitted from the internal combustion engine
Implementation Method 2
The oxidation catalyst is arranged at an upstream-side of the NOx-occlusion-reduction-type catalyst and is supplied with unburnt fuel by post injection of an exhaust gas injector or an in-cylinder injector, thereby increasing an exhaust gas temperature
Implementation Method 3
When the exhaust gas is in a lean atmosphere, the NOx-occlusion-reduction-type catalyst occludes NOx contained in the exhaust gas
Implementation Method 4
when the exhaust gas is in a rich atmosphere, the NOx-occlusion-reduction-type catalyst detoxifies and releases the occluded NOx with hydrocarbon contained in the exhaust gas
Implementation Method 5
it is necessary to periodically perform SOx purge of supplying unburnt fuel to the upstream oxidation catalyst to increase an exhaust gas temperature to a SOx separation temperature by post injection or exhaust gas pipe injection so as to separate SOx from the NOx-occlusion-reduction-type catalyst
Data Source
AI summary
An internal combustion engine control device including an oxidation catalyst heating value estimation unit 88A, a NOx catalyst heating value estimation unit 88B, an oxidation catalyst temperature estimation unit 88C, a NOx catalyst temperature estimation unit 88D, and switches 801, 802, 803 that switch between an enabled state in which processing performed by the oxidation catalyst heating value estimation unit 88A and the oxidation catalyst temperature estimation unit 88C is executed and a disabled state in which the processing performed by the oxidation catalyst heating value estimation unit 88A and the oxidation catalyst temperature estimation unit 88C is not executed, wherein the control device is configured to be applied to both an exhaust gas purification system including an NOx-occlusion-reduction-type catalyst and an oxidation catalyst and an exhaust gas purification system including the NOx-occlusion-reduction-type catalyst and not including the oxidation catalyst.