Engine Emission Control via Dual Sliding Window
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Solution Overview
Problem
Current emission control strategies for internal combustion engines face challenges in maintaining pollutant limits across varying operating conditions, particularly during sudden accelerations and when the exhaust gas after-treatment system (ATS) is not efficiently heated, leading to potential exceedance of emission limits.
Innovation Solution
Implementing a dual sliding window approach where a first window measures past emissions and a second window estimates future emissions based on current engine and ATS conditions, allowing for adjustment of combustion parameters and ATS heating strategies to maintain compliance with emission limits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the vehicle accelerates suddenly or the ATS is not efficiently heated, then emission limits are exceeded, but engine performance and responsiveness are compromised if restrictive control parameters are applied continuously
Solution Approach 1:
The system performs preliminary actions by heating the ATS in advance during low-load conditions and building up a buffer of compliant emissions before high-load periods. This allows the ATS to be ready for sudden accelerations without compromising emission limits, while engine performance is maintained during the buffer-building phase.
Solution Approach 2:
The control system dynamically adjusts combustion parameters and ATS heating strategies based on real-time operating conditions. During sudden accelerations, the system responds by adjusting EGR rates, injection timing, and ATS temperature control to maintain compliance without continuously restricting engine performance during normal operation.
2Object-generated harmful factors
If combustion parameters are restricted to minimize primary emissions, then emission limits are met, but engine performance and efficiency are reduced
Solution Approach 1:
The system uses feedback from emissions measurements and ATS temperature sensors to dynamically adjust combustion parameters. Instead of continuously restricting parameters, the system monitors actual emissions and ATS state, then adjusts EGR rates, injection timing, and valve timing to minimize primary emissions only when necessary while maintaining performance during conditions where emissions are already compliant.
Solution Approach 2:
The system changes operating parameters such as EGR rate, injection timing, compression ratio, and valve timing based on real-time conditions. These parameter changes allow the system to minimize primary emissions when needed while restoring performance-oriented parameters when emission risks are low, avoiding continuous performance restriction.
3Object-generated harmful factors
If the ATS is heated to improve NOx neutralization efficiency, then secondary emissions are reduced, but fuel consumption increases
Solution Approach 1:
The system applies periodic or pulsed heating to the ATS rather than continuous heating. Heating is activated during low-load conditions or when emissions buffering is favorable, and deactivated during high-load conditions where primary emissions are already high. This periodic action reduces fuel consumption while maintaining ATS efficiency when it provides the greatest benefit.
Solution Approach 2:
The system performs preliminary heating of the ATS during low-load conditions before high-emission events occur. This advance heating ensures the ATS is ready to efficiently neutralize secondary emissions during subsequent high-load operation without requiring continuous fuel-intensive heating, thereby reducing overall fuel consumption.
4Reliability
If emission control measures are continuously applied, then emission limits are consistently met, but engine responsiveness and drivability are degraded
Solution Approach 1:
The system dynamically switches between emission-oriented and performance-oriented control strategies based on real-time operating conditions. During sudden accelerations or when ATS temperature is insufficient, emission control measures are applied. During steady-state low-emission conditions, the system relaxes control parameters to improve responsiveness and drivability, maintaining compliance through adaptive rather than continuous restriction.
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 effectively manages emissions by minimizing primary emissions and activating ATS heating strategies as needed, ensuring compliance with emission limits while optimizing engine performance.
Implementation Method 1
the addition of a urea-based reducing agent upstream of an SCR catalytic converter
Implementation Method 2
the valve that controls the flow of exhaust gases recirculated through the cylinders of the internal combustion engine
Implementation Method 3
the SCR catalytic converter, which is part of the ATS, needs to reach at least 250°C in order to be efficient
Data Source
Figure 1~3
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AI summary
A method for controlling an assembly comprising an internal combustion engine and an exhaust gas after treatment device (ATS) of a terrestrial vehicle comprising a procedure for measuring (L1) an emission of at least a pollutant within a legal sliding window (Lw), having a first amplitude such as to represent a predetermined work generated, or a distance travelled, by the vehicle and a procedure for verifying (L2) whether an average emission value in said sliding window (Lw) is less than an emission limit value (Lim), the method further comprising the steps of adjusting operating parameters of the assembly, based on an average emission calculated over a sub-window (Pw) of said sliding window and an estimate of the emission in a second future window contiguous with said sub-window.