Article
Acoustics
Xuefeng Zhang, Jie Ai
Summary: This paper investigates novel criteria of the bounded real lemma corresponding to the H (infinity) norm of descriptor fractional order systems with 0 < alpha < 1. The conditions are presented in terms of strict linear matrix inequalities, which replace complex decision variables with real decision variables. Based on this new bounded real lemma, output feedback robust H (infinity) control for uncertain DFOS with bounded norm is studied for the first time. Unlike existing results, the presented results are more convenient for controller design and can be directly solved using any linear matrix inequality toolbox.
JOURNAL OF VIBRATION AND CONTROL
(2023)
Article
Automation & Control Systems
Ankit Gupta, Hakan Koroglu, Paolo Falcone
Summary: This paper presents an algorithm for computing polytopic robust control-invariant sets for rationally parameter-dependent systems with additive disturbances. The algorithm utilizes novel linear matrix inequalities feasibility conditions and a newly developed method for volume maximization to compute RCI sets with maximized volumes, which are symmetric around the origin and have a user-defined level of complexity. Unlike many similar approaches, the algorithm directly computes RCI sets without requiring control inputs to be in a specific feedback form.
INTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL
(2021)
Article
Mathematics
Tawfik Guesmi, Badr M. Alshammari, Yosra Welhazi, Hsan Hadj Abdallah, Ahmed Toumi
Summary: This paper presents a new control technique based on uncertain fuzzy models for handling uncertainties in nonlinear dynamic systems. The proposed strategy is tested on a multimachine power system subject to disturbances, and the effectiveness of the suggested fuzzy controller is compared with conventional regulators.
Article
Computer Science, Artificial Intelligence
Wei Zheng, Hak-Keung Lam, Fuchun Sun, Shuhuan Wen
Summary: This article discusses delay-dependent Takagi-Sugeno (T-S) fuzzy state feedback control and exponential admissibility analysis for a class of T-S fuzzy singular uncertain systems. A T-S fuzzy model is used to approximate the singular uncertain system with time-varying delay, saturation input, and unmatched disturbance. The delay-dependent T-S fuzzy state feedback controller is designed using the T-S fuzzy model, and delay-dependent exponential admissibility conditions are derived using free-weighting matrices and delay-dependent Lyapunov-Krasovskii functional. The convex hull lemma is used to enhance controller design flexibility, and the Schur complement lemma and Gronwall Bellman lemma are employed to derive less conservative delay-dependent stability conditions. The controller design problem is converted into linear matrix inequalities (LMIs) optimization constraints using the exact invariant set with less conservativeness. Simulation examples are presented to demonstrate the effectiveness of the proposed methods.
IEEE TRANSACTIONS ON FUZZY SYSTEMS
(2022)
Article
Mathematics, Interdisciplinary Applications
Bingxin Li, Yaowei Liu, Xin Zhao
Summary: This paper studies H infinity and robust H infinity control for fractional order systems (FOS) with order 0<<1. Necessary and sufficient conditions for H infinity control and state feedback controller design are proposed. Robust H infinity control for FOS with uncertainty is also studied, and a state feedback controller is designed. These conditions are based on linear matrix inequalities (LMI) and can be easily solved using the LMI toolbox. The effectiveness of these conditions is verified through two numerical examples.
FRACTAL AND FRACTIONAL
(2022)
Article
Mathematics, Applied
Serdar Coskun
Summary: This work focuses on addressing the robust output-feedback Script capital H-infinity control problem for a class of uncertain Takagi-Sugeno (T-S) fuzzy systems with state time-varying delays. A robust control strategy based on Lyapunov-Krasovskii functionals is derived, and a full-order robust dynamic output-feedback Script capital H-infinity controller is designed using convex programming toolbox. The effectiveness and merits of the proposed approaches are demonstrated through three examples.
MATHEMATICAL METHODS IN THE APPLIED SCIENCES
(2022)
Article
Mathematics, Interdisciplinary Applications
Bingxin Li, Xiangfei Zhao, Yaowei Liu, Xin Zhao
Summary: This paper studies the robust H-infinity control for fractional-order switched systems (FOSSs) with uncertainty. The fractional-order switching law for FOSSs is proposed and the control is proven based on the switching law and linear matrix inequalities (LMIs). The control method for FOSSs with a state feedback controller is extended, and the LMI-based condition of robust H-infinity control for FOSSs with uncertainty is proven. The effectiveness of the proposed methods is verified through simulation examples.
FRACTAL AND FRACTIONAL
(2022)
Article
Automation & Control Systems
Ariadne L. J. Bertolin, Ricardo C. L. F. Oliveira, Giorgio Valmorbida, Pedro L. D. Peres
Summary: This article addresses the problem of static output-feedback control design for uncertain discrete-time Lur'e systems with bounded nonlinearities, proposing new synthesis conditions based on linear matrix inequalities and an iterative algorithm to search for stabilizing gains. The approach can handle different types of constraints without introducing additional conservatism.
INTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL
(2022)
Article
Mathematics, Interdisciplinary Applications
Ri Liu, Zhe Wang, Xuefeng Zhang, Jianxu Ren, Qinglong Gui
Summary: This paper investigates a class of variable-order fractional interval systems in which the system matrices are affected by the fractional order. Sufficient conditions for robust stability and stabilization conditions subject to actuator saturation are proposed. The stability region is estimated using an optimization problem, and three numerical examples are provided to verify the effectiveness of the results.
FRACTAL AND FRACTIONAL
(2022)
Article
Automation & Control Systems
Jun Ma, Haiyue Zhu, Masayoshi Tomizuka, Tong Heng Lee
Summary: This article introduces a method for designing a fixed-order controller that ensures robust stability and performance in the presence of bounded parametric uncertainties. Utilizing Hurwitz polynomials and the notion of positive realness, the robust stability condition is successfully constructed, along with robust performance criteria based on bounded realness analysis. The conditions for robust stability and performance are expressed in the framework of linear matrix inequality (LMI) constraints, allowing for efficient resolution.
IEEE TRANSACTIONS ON SYSTEMS MAN CYBERNETICS-SYSTEMS
(2022)
Article
Automation & Control Systems
Jun Ma, Haiyue Zhu, Xiaocong Li, Wenxin Wang, Clarence W. de Silva, Tong Heng Lee
Summary: This article investigates the design of a robust fixed-order controller for single-input-single-output (SISO) polytopic systems with interval uncertainties. It establishes the equivalence between strictly positive realness (SPRness) and strictly bounded realness (SBRness) and transforms the specifications on robust stability and performance into the SPRness of newly constructed systems. The proposed methodology significantly reduces the computational burden and provides less conservative requirements for system performance.
IEEE TRANSACTIONS ON SYSTEMS MAN CYBERNETICS-SYSTEMS
(2023)
Article
Automation & Control Systems
Payam Haghighi, Babak Tavassoli
Summary: This article addresses the problem of robust static output feedback H-infinity control for networked control systems with uncertainties in both controlled-plant and communication subsystems. It employs Markov chains to model the network-induced delays and derives a new sufficient condition expressed in terms of linear matrix inequalities for the robust H-infinity control problem without constraints on matrix variables.
INTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL
(2021)
Article
Automation & Control Systems
Yahui Xu, Zhengchao Xie, Jing Zhao, Wenfeng Li, Panshuo Li, Pak Kin Wong
Summary: This paper investigates the problem of non-fragile H-infinity control for uncertain active suspension systems with time-delay using a fuzzy control approach in the finite frequency domain. A T-S fuzzy model is constructed, and a sufficient condition is presented to ensure stability and desired performance simultaneously, which is further transformed into a convex optimization problem. Numerical simulations demonstrate the effectiveness and performance advantages of the proposed control approach.
JOURNAL OF THE FRANKLIN INSTITUTE-ENGINEERING AND APPLIED MATHEMATICS
(2021)
Article
Computer Science, Information Systems
Bruno Sereni, Roberto Kawakami Harrop Galvao, Edvaldo Assuncao, Marcelo Carvalho Minhoto Teixeira
Summary: In this paper, a control approach for robust stabilization of LTI systems with non-negligible sensor and actuator dynamics subject to time-delayed signals is proposed. An augmented model is obtained to incorporate the plant, sensor, and actuator dynamics as well as the time-delay effect. Pade Approximation is used to model the time-delay impact on the feedback loop. A static output-feedback control law is composed using the sensor outputs as the actual plant state variables are not available for feedback. Robust controller gains are computed using a two-stage strategy based on LMI for less conservative conditions. Homogeneous-polynomial Lyapunov functions and other decision variables of arbitrary degree are considered for improving transient response and disturbance rejection. The effectiveness of the proposed strategy is demonstrated through the design of a controller for the lateral axis dynamics of an aircraft and other academic examples.
Article
Automation & Control Systems
Renan L. Pereira, Matheus S. de Oliveira
Summary: This technical article proposes new robust stabilization conditions for discrete-time linear parameter-varying (LPV) systems with linear fractional representation (LFR). The proposed conditions rely on the use of slack variables and decision matrices associated with the LFR approach to provide new controller designs. The article also addresses parameter-dependent Lyapunov functions and full-block multipliers to obtain less conservative synthesis conditions for discrete-time LPV/LFR systems. Design conditions are formulated as linear matrix inequalities to generate robust state-feedback and output-feedback controllers. Numerical examples demonstrate the effectiveness of the proposed method.
IEEE TRANSACTIONS ON AUTOMATIC CONTROL
(2023)
