Engine Control Predicting Accelerator Off to Stop Regeneration
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Solution Overview
Problem
Excessive unburned fuel entering the EGR system during exhaust gas purification system regeneration and accelerator off states leads to clogging and malfunction, as high concentrations of hydrocarbons condense and deposit in the EGR system components.
Innovation Solution
An internal combustion engine with a control method that monitors the purification situation and road situation to predict when the accelerator will be off, stopping regeneration fuel injection before the actual off state to prevent unburned fuel from entering the EGR system, and maintaining the exhaust gas purification system warm by opening the EGR valve during the off state.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If unburned fuel is supplied to the exhaust gas purification system during regeneration, then the purification situation is restored by oxidizing unburned fuel and increasing exhaust gas temperature, but excessive unburned fuel enters the EGR system causing hydrocarbon deposition and clogging
Solution Approach 1:
The control device predicts future accelerator off situations using road gradient information and stops regeneration fuel injection before the accelerator actually becomes off. This preliminary action prevents unburned fuel from entering the EGR system during periods when EGR valve opening would cause hydrocarbon deposition, while still allowing regeneration to proceed during safe periods.
Solution Approach 2:
The control device continuously monitors both the purification situation (differential pressure across DPF) and predicted road situations (accelerator off predictions based on gradient data). This feedback mechanism allows dynamic adjustment of regeneration fuel injection timing, stopping injection when prediction indicates upcoming accelerator off state to prevent EGR system contamination.
2Temperature
If a larger amount of unburned fuel is supplied to increase exhaust gas temperature during accelerator off state, then the exhaust gas purification system temperature is maintained, but excessive unburned fuel enters the EGR system
Solution Approach 1:
By predicting accelerator off situations in advance using road gradient data, the control device stops regeneration fuel injection before the accelerator actually becomes off. This timing prediction allows the system to avoid injecting fuel during periods when it would subsequently enter the EGR system, while still maintaining temperature through strategically timed injection during safe periods.
3Reliability
If regeneration control is executed during accelerator off state, then exhaust gas purification system is regenerated, but the temperature of exhaust gas decreases and excessive unburned fuel is required
Solution Approach 1:
The control device uses predicted road situation data to determine optimal timing for regeneration fuel injection. By stopping injection before predicted accelerator off events, the system concentrates fuel injection during periods when the accelerator is on, reducing total fuel quantity needed while still achieving effective regeneration.
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
Prevents excessive deposits in the EGR system, avoids clogging and malfunction, reduces fuel consumption by maintaining the exhaust gas purification system temperature, and minimizes the amount of unburned fuel required for regeneration.
Implementation Method 1
oxidizing the unburned fuel by the oxidation catalyst, and then increasing a temperature of the exhaust gas by an oxidation heat
Implementation Method 2
oxidizing the unburned fuel by the oxidation catalyst
Implementation Method 3
cool the EGR gas by an EGR cooler arranged in an EGR passage
Implementation Method 4
the hydrocarbon is condensed and deposited on a wall surface of the EGR passage or in the EGR valve and the EGR cooler
Data Source
AI summary
A control device (40) is connected to a differential pressure sensor (41), a navigation system (42), and a fuel injection valve (17). The control device (40) is configured to: execute a regeneration control of monitoring a purification situation (C1) and supplying unburned fuel (F2), which is injected from the fuel injection valve (17) and does not contribute to driving, to an exhaust gas purification system (20) in a case where the purification situation (C1) becomes a deteriorated situation (Ca); and execute a control of monitoring a road situation (C2) and stopping the regeneration control before the road situation (C2) actually becomes an accelerator off situation (Cb) in which an accelerator opening degree (θ1) of an accelerator pedal (43) becomes off.