Fuel Injection Control Adaptive Reflection Speed
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In partial lift injection, the estimation accuracy of actual injection quantity is poor due to destabilized valve body behavior, and sudden changes in injection characteristics, such as those caused by fuel injection valve exchange, lead to delayed reflection of correction quantities, affecting accurate control of injection quantity.
Innovation Solution
A fuel injection control device with a conduction time calculation unit, detection unit, estimation unit, correction unit, sudden change determination unit, and reflection speed setting unit to gradually reflect correction quantities, increasing reflection speed during sudden changes and maintaining gradual reflection during aging-related changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If correction quantity is immediately reflected on requested injection quantity, then response speed to injection characteristic changes is improved, but poor estimation accuracy in partial lift injection causes inaccurate correction
Solution Approach 1:
The patent applies dynamics by making the reflection speed adaptive rather than fixed. The control device dynamically adjusts the reflection speed based on whether a sudden change in injection characteristic is detected. When sudden change is detected, reflection speed is set to first speed (faster); when not detected, reflection speed is set to second speed (slower). This dynamic adjustment resolves the contradiction between response speed and estimation accuracy.
Solution Approach 2:
The patent changes the parameter of reflection speed based on the detection result. The reflection speed parameter is switched between two values (first speed and second speed) depending on the state of injection characteristic change. This parameter change allows the system to optimize between fast response and accurate correction by selecting appropriate reflection speeds for different operational conditions.
2Measurement precision
If correction quantity is reflected gradually, then poor estimation accuracy is suppressed, but response to sudden changes in injection characteristic is delayed
Solution Approach 1:
The system dynamically adjusts the reflection speed based on the operational state. When sudden change in injection characteristic is detected, the reflection speed increases to first speed, reducing response delay. When sudden change is not detected, reflection speed is maintained at second speed to suppress inaccurate corrections. This dynamic behavior resolves the contradiction between correction accuracy and response delay.
Solution Approach 2:
The reflection speed parameter is changed based on the detection of sudden changes. The control device switches between two discrete parameter values (first speed and second speed) to optimize the trade-off between response time and correction accuracy for different operational conditions.
3Speed
If high reflection speed is used, then response to valve exchange is improved, but poor estimation accuracy in partial lift injection causes control instability
Solution Approach 1:
The patent applies dynamics by conditionally adjusting reflection speed based on the detection of sudden changes. High reflection speed (first speed) is applied only when sudden change is detected, and low reflection speed (second speed) is applied when sudden change is not detected. This conditional dynamic adjustment ensures control stability while maintaining fast response when needed.
Solution Approach 2:
The reflection speed parameter is changed based on the operational state detected by the sudden change determination unit. The parameter switches between first speed and second speed to maintain control stability while enabling fast response to genuine sudden changes in injection characteristic.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A fuel injection control device includes a conduction time calculation unit (S14), a detection unit (54), an estimation unit (55), a correction unit (S13), a sudden change determination unit (S41, S41a), and a reflection speed setting unit (S12). The conduction time calculation unit calculates a conduction time of an electric actuator corresponding to a requested injection quantity during partial lift injection. The detection unit detects a physical quantity having a correlation with an actual injection quantity during the partial lift injection. The estimation unit estimates the actual injection quantity on the basis of a detection result of the detection unit. The correction unit corrects the requested injection quantity by a correction quantity corresponding to a deviation between the actual injection quantity and the requested injection quantity. The sudden change determination unit determines whether or not the correction quantity is in a sudden change state on the basis of whether or not the correction quantity has changed from a previous value by a prescribed quantity or more. The reflection speed setting unit, in setting a reflection speed at which the correction unit reflects the correction quantity on the requested injection quantity gradually for a prescribed period of time, sets the reflection speed when the sudden change determination unit determines the correction quantity to have changed suddenly at a speed higher than the reflection speed when the sudden change determination unit determines the correction quantity not to have changed suddenly.