Supercharger Boost Pressure Control with Gradual Target Adjustment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing control apparatuses for internal combustion engines with superchargers face challenges in efficiently controlling boost pressure to prevent overshoot and ensure stable operation, particularly in maintaining torque within the capacity of the drive system, which can lead to system failure and reduced marketability.
Innovation Solution
A control apparatus that includes a boost-pressure acquiring unit, a target steady-state boost pressure calculating unit, a first and second boost pressure controller, and an inhibiting/allowing unit, which performs feedback control algorithms to adjust the target boost pressure gradually using different rates and thresholds to prevent overshoot and maintain the boost pressure within acceptable limits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the target boost pressure is set to the target steady-state boost pressure immediately, then the response speed of boost pressure control is improved, but the boost pressure overshoots the target value causing harmful effects
Solution Approach 1:
The control apparatus sets the target boost pressure to a preliminary value lower than the target steady-state boost pressure at the start of control. This preliminary action prevents immediate overshoot while the boost pressure is building up. As the actual boost pressure approaches the preliminary target value, the target boost pressure is gradually increased to the final target steady-state value, achieving both fast response and overshoot prevention.
Solution Approach 2:
The target boost pressure is not fixed but dynamically adjusted during the control process. The control apparatus transitions from a static preliminary target value to a dynamic gradual increase phase, and finally to the target steady-state value. This dynamic adjustment of the target pressure profile allows the system to adapt to the actual boost pressure buildup rate, preventing overshoot while maintaining fast response.
2Productivity
If the boost pressure is controlled to reach the target steady-state boost pressure quickly, then the productivity of the engine is improved, but the torque exceeds the upper limit of the drive system capacity causing system failure
Solution Approach 1:
The control apparatus continuously monitors the actual boost pressure and compares it with the target boost pressure. Based on this feedback, the control apparatus adjusts the target boost pressure dynamically. When the actual boost pressure approaches the preliminary target value, the system gradually increases the target to the final steady-state value, ensuring the torque remains within drive system capacity while maximizing engine productivity.
Solution Approach 2:
By setting a preliminary target boost pressure lower than the target steady-state value at the beginning of control, the system prepares for a controlled ascent. This preliminary action ensures that the boost pressure increases in a controlled manner, preventing torque from exceeding drive system capacity limits while still achieving high productivity through the subsequent gradual increase to the target steady-state value.
Data Source
AI summary
A control apparatus for an internal combustion engine with a supercharger includes a boost-pressure detector. When first boost pressure control to control the supercharger such that a boost pressure reaches a target pressure starts, starts, the target pressure is set to an initial target pressure, gradually at a first rate, and then gradually increased to a steady-state target boost pressure at a second rate smaller than the first rate if the boost pressure is equal to or higher than a threshold pressure. Second boost pressure control is performed such that the boost pressure reaches a steady-state target boost pressure. Inhibiting/allowing circuitry is configured to inhibit execution of the first boost pressure control and allow execution of the second boost pressure control if the boost pressure is lower than the steady-state target boost pressure and if the steady-state target boost pressure is lower than the threshold pressure.