Engine Control System Using Unified Formula for Exhaust Gas Recirculation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing control systems for internal combustion engines require extensive manpower to set up maps for calculating exhaust gas recirculation ratios, especially when considering both internal and external recirculation, and are prone to errors due to changes in atmospheric pressure and operating conditions.
Innovation Solution
A control system that calculates the exhaust gas recirculation ratio using a simplified method involving a throttle valve, evaporative fuel/air mixture, and sensors to detect engine rotational speed and intake pressure, reducing the need for multiple maps and allowing accurate calculation regardless of atmospheric changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the conventional method using multiple maps for calculating exhaust gas recirculation ratio is used, then the calculation accuracy under various operating conditions is improved, but the manpower required for setting up maps becomes excessively large
Solution Approach 1:
The patent creates a universal calculation method that works across all operating conditions using a single set of formulas and parameters, eliminating the need for multiple condition-specific maps. The exhaust gas recirculation ratio is calculated using the unified equation: REGRT = (GATH - GINGASCYL) / GATH, where GATH is the theoretical intake air amount and GINGASCYL is the actual intake gas amount, making the system multi-functional for all operating scenarios without requiring separate maps for different conditions.
Solution Approach 2:
The patent changes the approach from using multiple discrete maps to using continuous parameter-based calculations. Instead of relying on pre-set maps for different operating conditions, the system dynamically calculates the exhaust gas recirculation ratio by changing parameters such as intake pressure, engine rotational speed, and throttle valve opening in real-time, allowing accurate calculation across all operating points without manual map setup.
2Reliability
If the residual gas ratio calculation method with multiple parameters is used, then the calculation can account for internal exhaust gas recirculation, but the manpower for setting tables or maps becomes large
Solution Approach 1:
The patent merges the calculation of internal and external exhaust gas recirculation into a single unified formula. By combining the theoretical intake air amount (GATH) and actual intake gas amount (GINGASCYL) into one calculation, the system accurately represents total exhaust gas recirculation without requiring separate tables or maps for internal and external recirculation components, thereby reducing the overall complexity and manpower required for setup.
3Adaptability or versatility
If maps are set for various operating conditions to calculate exhaust gas recirculation ratio, then the calculation covers all operating conditions, but the manpower required for setting maps becomes excessively large
Solution Approach 1:
The patent extracts the essential calculation logic from the complex map-based system and formulates it as a standalone mathematical model. By taking out the core calculation principle and expressing it through fundamental parameters (intake pressure, engine rotational speed, throttle valve opening), the system achieves versatility across all operating conditions without requiring the extensive map data that would otherwise be needed to cover every possible operating scenario.
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 significantly reduces the manpower required for setting up maps and ensures accurate exhaust gas recirculation ratio calculations, improving engine control and preventing knocking during rapid acceleration by setting the recirculation ratio to zero when necessary.
Implementation Method 1
an evaporative fuel passage for supplying an evaporative fuel/air mixture to the intake passage (2). The evaporative fuel/air mixture is a mixture of air and evaporative fuel generated in a fuel tank for supplying fuel to the engine
Data Source
AI summary
A control system for an internal combustion engine having a throttle valve disposed in an intake passage of the engine is provided. A wide-open intake air amount, which is an intake air amount corresponding to a state where the throttle valve is fully opened, is calculated according to the engine rotational speed, and a theoretical intake air amount, which is an intake air amount corresponding to a state where no exhaust gas of the engine is recirculated to a combustion chamber of the engine, is calculated according to the wide-open intake air amount and the intake pressure. An intake air amount of the engine is detected or estimated, and an amount of the evaporative fuel/air mixture supplied through the evaporative fuel passage to the intake passage is calculated. An intake gas amount is calculated by correcting the intake air amount using the evaporative fuel/air mixture amount, and an exhaust gas recirculation ratio is calculated using the theoretical intake air amount and the intake gas amount. The engine is controlled using the calculated exhaust gas recirculation ratio.