Supercharged Engine Control Apparatus Scavenging Torque
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Solution Overview
Problem
Existing torque demand control methods for supercharged engines are inaccurate in realizing required torque due to scavenging effects, where intake pressure exceeds exhaust pressure, leading to a shortfall in in-cylinder air amount and resulting torque.
Innovation Solution
A control apparatus for supercharged engines determines the operation amount of the intake valve driving device based on the target in-cylinder air amount, with the exhaust valve overlap amount influencing scavenging, allowing for accurate torque realization by adjusting the intake and exhaust valve timings and using scavenging to enhance air flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If torque demand control is applied to supercharged engines using conventional NA engine methods, then the control system can be implemented with existing throttle and valve timing mechanisms, but the in-cylinder air amount becomes insufficient due to scavenging effects, resulting in torque shortfall
Solution Approach 1:
The patent changes the control parameters by introducing a correction value to the target in-cylinder air amount calculation. This correction value compensates for the air loss due to scavenging, where intake pressure exceeds exhaust pressure. By adjusting the target air amount parameter rather than the physical scavenging process itself, the system maintains torque demand control functionality while achieving accurate torque realization in supercharged conditions
Solution Approach 2:
The patent implements feedback control by calculating the difference between actual and target in-cylinder air amounts, then using this difference to adjust the operation amounts of air amount actuators. The correction value for target air amount is determined based on operating conditions and fed back into the control calculation, creating a closed-loop system that compensates for scavenging effects and achieves precise torque control
2Quantity of substance
If the throttle opening is increased to compensate for air amount shortfall, then more air can enter the cylinder, but the intake pressure reaches upper limit and further throttle adjustment becomes ineffective
Solution Approach 1:
The patent applies preliminary action by pre-calculating a correction value for the target in-cylinder air amount based on expected scavenging losses under different operating conditions. This correction is applied before the actual control execution, allowing the system to anticipate and compensate for air loss due to scavenging. By preparing the corrected target value in advance, the control system can achieve accurate torque control without needing to react to pressure limits or make complex real-time adjustments
Data Source
AI summary
It is an object of the invention to enhance the possibility of realizing a required torque in a supercharging region where scavenging occurs in a control apparatus for a supercharged engine. In order to achieve this object, the control apparatus for the supercharged engine according to the invention determines an operation amount of an intake valve driving device from a target in-cylinder air amount that is calculated from a required torque, and determines an operation amount of a throttle from a target intake valve passing air amount that is obtained by adding an amount of air blowing through an interior of a cylinder to the target in-cylinder air amount.