Turbocharger Sub ECU Control via Predictive Valve Opening
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In engine systems with turbochargers, feedback control often results in delayed responses and complex gain adjustments, leading to potential deterioration of engine control performance due to differences between predicted and actual turbocharger operations by the main and sub ECUs.
Innovation Solution
An auxiliary-machine control device and system that includes a command-value acquisition unit, operation-amount calculation unit, and operation-amount determination unit to manage the operation of the turbocharger within predetermined allowable ranges, adjusting these ranges based on change rates and deviations to ensure effective control without impairing engine performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If feedback control is used to control the turbocharger, then the sub ECU can achieve target boost pressure, but the response is delayed and control gain adjustment becomes difficult or complicated
Solution Approach 1:
The main ECU performs preliminary calculation of the turbine valve opening degree based on the boost pressure command value and outputs it to the sub ECU in advance. This predictive approach allows the sub ECU to prepare control actions before they are needed, reducing the response delay inherent in traditional feedback control while maintaining precise boost pressure control.
2Speed
If model predictive control is used where main ECU and sub ECU independently predict behavior, then control response is improved, but engine control performance may deteriorate due to differences between predicted and actual turbocharger operations
Solution Approach 1:
The sub ECU receives feedback from the main ECU in the form of a calculated turbine valve opening degree and compares it with its own predictions. The sub ECU adjusts its control strategy based on this feedback, ensuring that its independent predictive control actions remain consistent with the main ECU's overall engine control objectives, thus maintaining both fast response and reliable engine control.
Solution Approach 2:
The turbine valve opening degree calculated by the main ECU acts as an intermediary between the main ECU's engine control objectives and the sub ECU's turbocharger control actions. This intermediary value serves as a reference that guides the sub ECU's independent predictive control, ensuring coordination between the two control units without requiring constant direct communication or sacrificing response speed.
3Productivity
If the sub ECU independently controls the turbocharger, then turbocharger performance is utilized effectively, but abnormal operations may occur that impair engine control
Solution Approach 1:
The sub ECU dynamically adjusts its control strategy based on the turbine valve opening degree feedback from the main ECU. When the calculated opening degree indicates safe operating conditions, the sub ECU can independently optimize turbocharger performance. When the feedback suggests potential abnormal operations, the sub ECU automatically adjusts its control parameters to maintain engine control stability, creating a dynamic balance between performance and reliability.
Data Source
Figure 1
Figure 2A~3
Figure 4
AI summary
An auxiliary-machine control device equipped with: a command-value acquisition unit for acquiring an operation command value for a device to be controlled and an allowable range for the operation amount of control means for controlling the operating state of the device to be controlled; an operation-amount calculation unit for calculating the operation amount for the control means on the basis of the acquired operation command value; and an operation-amount determination unit for outputting the calculated operation-amount signal to the device to be controlled if the operation amount calculated by the operation-amount calculation unit falls within the allowable range, and outputting an upper-limit value or a lower-limit value for the operation-amount allowable range if the calculated operation amount falls outside of the allowable range.