Exhaust Device Temperature Control via Pre-calculated Delay Data
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Internal combustion engines with variable valves, exhaust turbo superchargers, and idle stop mechanisms face challenges in precisely forecasting and controlling exhaust device temperatures due to numerous affecting factors, leading to inefficiencies and increased man-hours for setting delay times in fuel injection systems.
Innovation Solution
A control method that computes exhaust gas temperature based on rotating speed, charging efficiency, ignition timing, equivalent ratio, external EGR rate, and supercharging pressure, and estimates exhaust device temperature using intake air amount, fluid temperature, and flow rate, allowing for transient corrections in ignition timing, equivalent ratio, and exhaust valve opening timing to maintain optimal temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If statistical models with constants corresponding to heat capacity or heat resistance are used to forecast exhaust device temperature, then temperature forecasting capability is improved, but device complexity and man-hours for matching increase significantly
Solution Approach 1:
The patent replaces complex statistical models with disposable, pre-calculated temperature rise delay time data that is stored in memory. Instead of using expensive and complex constant identification through parameter matching, the system uses simple lookup tables that can be easily stored and retrieved, achieving the same forecasting function with minimal complexity.
Solution Approach 2:
The patent substitutes the mechanical process of parameter identification and constant matching with an electronic data storage and retrieval system. The complex process of identifying heat capacity and heat resistance constants through experimental matching is replaced by storing pre-calculated delay time data in memory and simply retrieving it based on operating conditions.
2Measurement precision
If delay time is previously set in accordance with matching for systems with increased degree of freedom, then temperature control accuracy is improved, but man-hours for matching increase significantly
Solution Approach 1:
The patent performs the time-consuming matching process in advance during system design or initialization, storing the results as pre-calculated temperature rise delay time data. During actual operation, the system simply retrieves this pre-computed data based on current operating conditions, eliminating the need for repeated matching operations and significantly reducing operational man-hours.
3Temperature
If fuel supply amount is increased without considering exhaust device temperature, then fuel consumption increases, but exhaust device temperature control is achieved
Solution Approach 1:
The patent implements a feedback control system that continuously monitors exhaust device temperature and adjusts fuel supply accordingly. By using the estimated exhaust device temperature (retrieved from stored delay time data and current operating conditions), the system determines the appropriate fuel increase amount, ensuring temperature control while minimizing unnecessary fuel consumption.
Solution Approach 2:
The patent dynamically adjusts the fuel supply parameter based on the estimated exhaust device temperature and operating conditions. Instead of using a fixed fuel increase amount, the system varies the fuel supply parameter according to the retrieved temperature rise delay time and current temperature, achieving optimal balance between temperature control and fuel efficiency.
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 enables precise control of exhaust device temperatures, prevents excessive temperature rises, reduces fuel consumption, and minimizes damage by allowing for real-time adjustments based on estimated temperatures, improving engine efficiency and reducing operational complexity.
Implementation Method 1
the exhaust gas temperature can be indirectly detected on the basis of an internal resistance of an air fuel ratio sensor element
Implementation Method 2
a forecasting of a delay behavior of the exhaust device temperature from a change of the exhaust gas temperature is described by a statistical model having the exhaust gas temperature forecasting value as an input
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The invention provides a method for preferably controlling an internal combustion engine by precisely estimating a current value of a temperature of an exhaust device of an internal combustion engine provided with a variable valve, an exhaust turbo supercharger and the like, and controlling an affector of a temperature of an exhaust gas on the basis of a difference between a reference value of the exhaust device temperature and the current value of the exhaust device temperature. The method computes a temperature of an exhaust gas on the basis of a rotating speed, a charging efficiency, an ignition timing, an equivalent ratio, an external EGR rate, an exhaust valve opening timing, and a supercharging pressure, estimates a temperature of an exhaust device on the basis of the exhaust gas temperature, an amount of an intake air, a temperature of a fluid around the exhaust device and a flow rate around the exhaust device, and transiently corrects at least one of the ignition timing, the equivalent ratio, the external EGR rate, and the exhaust valve opening timing, on the basis of the estimation value and the reference value.