Robust Cascade Control inside a New Model-Matching Architecture
Abstract
:1. Introduction
- A new control structure with nested feedback loops from the states and feedforward loops from the set point will be proposed. A novel QFT solution will be given to compute the bounds and design the feedforward and the two feedback controllers for robust tracking, robust stability, and robust disturbance rejection.
- A method will be provided for determining the best distribution between the inner and outer loops of a predetermined amount of feedback over a fixed control bandwidth; a switching frequency will separate the working frequency bands of each loop. This will result in a pair of feedback controllers that minimize the amount of noise at the control input coming from the sensors. A sequential method will be detailed to design first the inner feedback controller, then the outer feedback controller, and finally the feedforward controller.
2. Architecture and Control Fundamentals
2.1. Control Structure
2.2. Robust Control under QFT Paradigm
3. Design Methodology
3.1. First Stage: Design of the Inner Feedback Controller
3.2. Second Stage: Design of the Outer Feedback Controller
3.3. Third Stage: Design of the Feedforward Controller
4. Design Example and Comparisons
4.1. Solution Achieved by the New Proposal
4.2. Comparatives with Other Structures and Strategies
4.3. Remarks on Disturbance Rejection and Integral Control
5. Validation on a Real System
6. Conclusions
Author Contributions
Funding
Data Availability Statement
Conflicts of Interest
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Design Strategy | Degrees of Freedom | |||||
---|---|---|---|---|---|---|
New architecture; | G (36) | (35) | (34) | 0.3429 | 0.001 | 0.1076 |
Model matching; outer feedback | (38) | (37) | —— | 78.0065 | 6085 | 0 |
Model matching; inner feedback | (40) | —- | (39) | 0.3780 | 0 | 0.1429 |
Double feedback; no feedforward | —– | (42) | (43) | 1.1882 | 0.0053 | 1.4065 |
New architecture; | (46) | (44) | (45) | 0.6929 | 0.3797 | 0.1004 |
New architecture; | (49) | (47) | (48) | 0.3586 | 0.00022 | 0.1284 |
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Rico-Azagra, J.; Gil-Martínez, M. Robust Cascade Control inside a New Model-Matching Architecture. Mathematics 2023, 11, 2523. https://doi.org/10.3390/math11112523
Rico-Azagra J, Gil-Martínez M. Robust Cascade Control inside a New Model-Matching Architecture. Mathematics. 2023; 11(11):2523. https://doi.org/10.3390/math11112523
Chicago/Turabian StyleRico-Azagra, Javier, and Montserrat Gil-Martínez. 2023. "Robust Cascade Control inside a New Model-Matching Architecture" Mathematics 11, no. 11: 2523. https://doi.org/10.3390/math11112523