Plant Control Device Reference Governor Constraint Optimization
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Solution Overview
Problem
Existing plant control devices face challenges in achieving favorable transient response characteristics while satisfying constraints, particularly in plants where response characteristics change with operation conditions, as they often fail to effectively manage constraints and maintain performance.
Innovation Solution
A plant control device incorporating a reference governor with an evaluation function that uses a penalty function to optimize the target value, allowing for online calculation and reducing calculation load, which includes a feedback controller and an observer to estimate the state of the closed loop system and correct the target value based on predicted values and constraints.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a reference governor is used to satisfy constraints by correcting target values, then constraint satisfiability is improved, but transient response characteristics deteriorate
Solution Approach 1:
The patent applies dynamics by making the evaluation function adaptive to changing operation conditions. The reference governor dynamically adjusts the evaluation function based on real-time operation conditions, allowing the system to maintain favorable transient response characteristics while satisfying constraints even when plant response characteristics vary with operating conditions.
Solution Approach 2:
The patent changes parameters by modifying the evaluation function parameters according to operation conditions. The reference governor adjusts parameters of the evaluation function based on detected operation conditions, enabling the system to optimize both constraint satisfaction and transient response characteristics under varying operating conditions.
2Reliability
If complex evaluation functions are used to optimize target values, then control performance is improved, but calculation load increases
Solution Approach 1:
The patent applies partial action by using a simplified evaluation function that focuses on essential optimization aspects. Rather than using overly complex evaluation functions, the reference governor employs a streamlined approach that achieves sufficient control performance while significantly reducing the calculation load on the control device.
Data Source
AI summary
A plant control device according to the present invention includes a feedback controller and a reference governor. The feedback controller is configured to determine a control input of a plant by feedback control so as to bring an output value of a control amount of the plant close to a target value. The reference governor is configured to calculate a future predicted value of a specific state quantity of the plant by using a model of a closed loop system including the plant and the feedback controller, and correct the target value that is given to the feedback controller based on the predicted value of the specific state quantity and a constraint that is imposed on the specific state quantity.