Engine Boost Pressure Control Apparatus for Overshoot Suppression
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Solution Overview
Problem
Existing boost pressure control systems for internal combustion engines face challenges in suppressing overshoots when transitioning from open-loop to feedback control, particularly when considering changes in fuel supply and gas compression, which affect gas pressure control.
Innovation Solution
A control apparatus that selectively employs single control and composite control based on the absolute value of the controlled variable's change rate, switching to composite control when the change rate exceeds a predetermined threshold to account for disturbances in fuel supply and gas compression, thereby stabilizing the control and reducing overshoots.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If open-loop control is used to rapidly increase boost pressure, then the rate of rise in boost pressure is improved, but overshoot occurs when transitioning to feedback control
Solution Approach 1:
The system performs preliminary open-loop control to quickly bring boost pressure near the target value before switching to feedback control. This preliminary action reduces the error magnitude, allowing subsequent feedback control to operate with smaller adjustments and minimize overshoot.
Solution Approach 2:
The control system dynamically switches between open-loop and feedback control modes based on the current state. Open-loop control is used when large pressure increase is needed, while feedback control takes over when precision is required, creating a dynamic adaptation to different operational phases.
2Manufacturing precision
If feedback control is used to precisely maintain target boost pressure, then manufacturing precision is improved, but the response speed decreases compared to open-loop control
Solution Approach 1:
The control process is segmented into two phases: an initial phase using open-loop control for rapid response, and a subsequent phase using feedback control for precise maintenance. This segmentation allows each control mode to operate in its optimal performance range.
Solution Approach 2:
The system maintains continuous useful action by seamlessly transitioning from open-loop to feedback control without interruption. The boost pressure control remains active throughout, with the control strategy adapting to maintain both speed and precision across different operational stages.
3Reliability
If composite control considering fuel supply changes is implemented, then reliability under disturbance is improved, but device complexity increases
Solution Approach 1:
The composite control system incorporates feedback mechanisms that monitor fuel supply changes and adjust boost pressure control accordingly. This feedback loop detects disturbances caused by fuel supply variations and compensates for them, maintaining reliability without requiring complete redesign of the control architecture.
Solution Approach 2:
The system adapts control parameters based on fuel supply conditions. When fuel supply changes are detected, the control algorithm modifies its parameters to account for the disturbance, allowing the same hardware to handle varying operational conditions through software-based parameter adjustment.
Data Source
AI summary
The invention relates to a control apparatus for an internal combustion engine (10) including a control target (60V, 52) that controls controlled variable (Pim, Regr). The control apparatus according to the invention is capable of selectively performing single control that is control for controlling the controlled variable to a target value thereof (Pimt, Regrt) without considering a change in the controlled variable that acts as a disturbance on the control of the controlled variable, and composite control that is control for controlling the controlled variable to the target value thereof in consideration of the change in the controlled variable that acts as the disturbance on the control of the controlled variable. The controlled variable is controlled to the target value thereof through the single control when an absolute value of a controlled variable change rate (Rpim, Rregr) is equal to or smaller than a predetermined value (Rpimth, Rregrth). The controlled variable is controlled to the target value thereof through the composite control when the absolute value of the controlled variable change rate is larger than the predetermined value.