Letter
Automation & Control Systems
MirSaleh Bahavarnia
Summary: This paper points out errors in Lemma 4.1 and Theorem 4.2 of Mazo et al. (2010) and proposes a corrected result. The errors were then corrected accordingly in the statement of Theorem 4.2.
Letter
Automation & Control Systems
Yuxin Su
Summary: A flaw is identified in the proof of Theorem 3 in Chiu (2012), casting doubt on the validity of the theorem and the claimed singularity avoidance by the proposed control given in equation (38) of Chiu (2012).
Letter
Automation & Control Systems
Bernard Brogliato
Summary: Interestingly, some controllers and stability results in Haddad and Lee (2020) can be shown to be equivalent to algorithms obtained from the implicit Euler discretization of a set-valued system, which is known to preserve many nice properties of the continuous-time dynamics after discretization, like the convergence towards the (discrete) sliding surface in a finite number of steps.
Letter
Automation & Control Systems
Arvo Kaldmae
Summary: It is concluded that claim (i) of Theorem 13 in the commented article is not true, indicating that a (s+1)th order retarded type input-output equation does not always exist for a nonlinear time-delay system with observability index s. However, the existence of a retarded type input-output equation is described for certain special cases.
Article
Engineering, Mechanical
Cong Wu
Summary: This note points out that the proof for a widely used asymptotic stability theorem for Caputo fractional-order systems is incorrect.
NONLINEAR DYNAMICS
(2021)
Article
Mathematics, Interdisciplinary Applications
Meng Zhang, Quanxin Zhu
Summary: This article extends the finite-time input-to-state stability (FTISS) to switched stochastic time-varying nonlinear systems with time delays, and analyzes the conditions for obtaining input-state stability of nonlinear switched stochastic delayed systems in the framework of finite time using the methods of comparison principle and average dwell-time approach.
CHAOS SOLITONS & FRACTALS
(2022)
Article
Multidisciplinary Sciences
Wei Hu
Summary: Novel stochastic finite-time stability criteria for stochastic nonlinear systems with stochastic impulse effects are established in this paper. The significance and usefulness of the results are demonstrated through an example.
Article
Automation & Control Systems
Gui-Hua Zhao, Xue Zhang
Summary: In this paper, the finite-time stabilization of a class of nonlocal Lipschitzian stochastic nonlinear systems with Markovian switching and stochastic inverse dynamics is investigated. The finite-time stability theory for stochastic nonlinear systems with Markovian switching under the framework of weak solutions is presented. Furthermore, a finite-time controller with state feedback is constructed for a class of stochastic high-order nonlinear systems with Markovian switching and stochastic inverse dynamics. It is proved that the trivial weak solution of the closed-loop system is globally finite-time stable in probability. Finally, the effectiveness of the proposed design method is verified through a simulation example.
INTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL
(2023)
Article
Automation & Control Systems
Haiqi Peng, Quanxin Zhu
Summary: This article focuses on the stochastic finite time stability (SFTS) and stochastic fixed time stability (SFIXTS) of switched stochastic nonlinear functional systems. It establishes several novel theorems on SFTS and SFIXTS using the Lyapunov-Razumikhin approach, stochastic analysis techniques, and stochastic process theory. The article also provides estimations of stochastic settling time, considering the effects of noise, time-delays, and switches.
INTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL
(2023)
Article
Engineering, Multidisciplinary
Yanis Ammouche, Antoine Jerusalem
Summary: The Monte Carlo method is commonly used for uncertainty estimation in mechanical engineering design. However, it has limitations in terms of computational time and scalability. To overcome these limitations, more efficient approaches like the Galerkin stochastic finite element method (GSFEM) and the collocation method have been proposed. GSFEM provides accurate output statistics, is sampling independent, and allows for modular operations. However, its application to nonlinear mechanical behavior is relatively unexplored.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2022)
Article
Automation & Control Systems
Rong-Heng Cui, Xue-Jun Xie
Summary: This paper focuses on the problem of output feedback stabilization of stochastic planar nonlinear systems with output constraint. By introducing new nonlinear mappings, adding a power integrator and homogeneous domination techniques, two new design and analysis frameworks are established in this paper to achieve stochastic asymptotic stability and stochastic finite-time stability of the trivial solution of the closed-loop system, while ensuring the requirements of almost sure boundedness of the closed-loop signals and the symmetric output constraint.
Article
Computer Science, Information Systems
Gui-Hua Zhao, Shu-Jun Liu
Summary: This study investigates the stochastic finite-time stability theory and finite-time stabilization of stochastic time-varying nonlinear systems with Markovian switching in the sense of weak solutions. A finite-time stabilization controller is constructively designed for a class of high-order stochastic nonlinear systems with Markovian switching, proving the global finite-time stability of the system's trivial weak solution. The proposed finite-time control method's effectiveness is illustrated through a numerical example.
SCIENCE CHINA-INFORMATION SCIENCES
(2022)
Article
Automation & Control Systems
Huifang Min, Shengyuan Xu, Baoyong Zhang, Qian Ma, Deming Yuan
Summary: This paper investigates the fixed-time stability theorem and state-feedback controller design for stochastic nonlinear systems. An improved fixed-time Lyapunov theorem is proposed with a more rigorous and reasonable proof procedure. A state-feedback controller is skillfully designed based on the backstepping technique and the addition of a power integrator method. It is proved that the proposed controller can render the closed-loop system fixed-time stable in probability.
IEEE-CAA JOURNAL OF AUTOMATICA SINICA
(2022)
Article
Automation & Control Systems
Jiaju Yu, Shuanghe Yu, Yan Yan
Summary: This paper studies the fixed-time stability of stochastic nonlinear systems and the fixed-time consensus of stochastic multi-agent systems. A new stability theorem and consensus protocol are proposed, and numerical examples are provided to illustrate the correctness of the theoretical results.
IET CONTROL THEORY AND APPLICATIONS
(2021)
Article
Automation & Control Systems
Wei Hu, Quanxin Zhu
Summary: This paper establishes the criteria for stochastic finite-time stability (SFTS) of switched stochastic nonlinear systems with nonlocal Lipschitz coefficients. The main tools used are mode-dependent limiting average dwell time, stopping time technology, and stochastic analysis theory. The criteria show the crucial roles of the diffusion coefficient, drift coefficient, and switching law in obtaining SFTS. Additionally, the criteria provide approaches for designing the switching law to achieve SFTS in switched stochastic systems containing both SFTS subsystems and stochastic finite-time unstable (SFTI) subsystems. An example is given to illustrate the importance and usefulness of the theoretical results.
INTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL
(2023)
Article
Instruments & Instrumentation
Ali Zolfagharian, Abbas Kouzani, Amir Ali Amiri Moghadam, Sui Yang Khoo, Saeid Nahavandi, Akif Kaynak
SMART MATERIALS AND STRUCTURES
(2019)
Article
Engineering, Mechanical
Ahmad Abu Alqumsan, Suiyang Khoo, Michael Norton
MECHANISM AND MACHINE THEORY
(2019)
Article
Engineering, Multidisciplinary
Ali M. Ay, Suiyang Khoo, Ying Wang
STRUCTURAL HEALTH MONITORING-AN INTERNATIONAL JOURNAL
(2019)
Article
Chemistry, Physical
Ali Zolfagharian, Akif Kaynak, Sui Yang Khoo, Jun Zhang, Saeid Nahavandi, Abbas Kouzani
Article
Automation & Control Systems
Xin Yu, Juliang Yin, Suiyang Khoo
Article
Automation & Control Systems
Xin Yu, Juliang Yin, Suiyang Khoo
Summary: This paper discusses the stochastic finite-time stability and instability of nonlinear stochastic differential equations with time-varying drift and diffusion terms. New conditions and theorems are proposed, and examples are provided to illustrate the application of the results.
INTERNATIONAL JOURNAL OF CONTROL
(2021)
Article
Mechanics
Ahmad Abu Alqumsan, Suiyang Khoo, Michael Norton
Article
Automation & Control Systems
Juliang Yin, Deng Ding, Suiyang Khoo
INTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL
(2020)
Review
Materials Science, Multidisciplinary
Muhammad Wajahat, Abbas Z. Kouzani, Sui Yang Khoo, M. A. Parvez Mahmud
Summary: Energy harvesting technologies are crucial for self-powered electronic devices, and triboelectric nanogenerators (TENGs) fabricated with nanomaterials are efficient in harvesting mechanical energy. Extrusion-based 3D printing is a reliable approach for developing TENG devices. This article analyzes the material combinations, design, structure formation, and output performance of extrusion-based 3D-printed TENGs, and discusses their applications and challenges.
JOURNAL OF MATERIALS SCIENCE
(2022)
Article
Automation & Control Systems
Mohammad Reza Chalak Qazani, Houshyar Asadi, Suiyang Khoo, Saeid Nahavandi
Summary: The hexapod manipulator is a commonly used motion platform, but its limited workspace poses challenges. Current MPC-based motion cueing algorithm methods are unable to fully consider the design parameters of hexapod mechanisms, resulting in users not experiencing realistic motion sensations.
IEEE TRANSACTIONS ON SYSTEMS MAN CYBERNETICS-SYSTEMS
(2021)
Article
Computer Science, Information Systems
Muhammad Nouman, Sui Yang Khoo, M. A. Parvez Mahmud, Abbas Z. Kouzani
Summary: This article provides a comprehensive review of contactless sensing methods for monitoring mental health. These methods allow objective collection of real-time data, which can be used to assess mental health conditions. The article investigates published research and categorizes the applications of contactless sensing methods. It also compares recent studies to show the effectiveness and reliability of these methods. Furthermore, the article highlights the existing challenges and suggests future research directions.
IEEE INTERNET OF THINGS JOURNAL
(2022)
Review
Construction & Building Technology
Muhammad Adil, M. A. Parvez Mahmud, Abbas Z. Kouzani, SuiYang Khoo
Summary: The integration of renewable and other distributed energy resources has imposed challenges on the traditional power grid. The increasing demand for green energy and energy trading is driving the need for innovative solutions in the energy market, especially with the rise of electric vehicles. The use of Stackelberg game in modeling energy trading interactions and strategies shows promise in optimizing payoffs and addressing challenges in the current energy trading framework.
SUSTAINABLE CITIES AND SOCIETY
(2021)
Article
Energy & Fuels
Hassan Ranjbarzadeh, Seyed Masoud Moghaddas Tafreshi, Mohd Hasan Ali, Abbas Z. Kouzani, Suiyang Khoo
Summary: This paper proposes a probabilistic model to reduce the cost and CO2 emissions of a multi-carrier microgrid. The proposed model optimizes the operation of the microgrid by managing energy producers, storage equipment, and energy trading using a multi-objective optimization model and fuzzy satisfying approach. Simulation results demonstrate the performance of the proposed model and the impact of electrifying heating and cooling on greenhouse gas emissions.
Proceedings Paper
Computer Science, Cybernetics
Ahmad Abu Alqumsan, Suiyang Khoo, Adetokunbo Arogbonlo, Saeid Nahavand
Summary: Continuum robots require a robust control design to achieve high accuracy and delicacy, facing challenges due to their nonlinearity and elasticity. The assumption of uncertainty matching condition is difficult to justify in practical applications, leading to the need for alternative control techniques.
2021 IEEE INTERNATIONAL CONFERENCE ON SYSTEMS, MAN, AND CYBERNETICS (SMC)
(2021)
Article
Geosciences, Multidisciplinary
Ahmed Abed Gatea Alshammary, Abbas Z. Kouzani, Akif Kaynak, Sui Yang Khoo, Michael Norton, Will P. Gates, Mustafa AL-Maliki, Jesus Rodrigo-Comino
Article
Automation & Control Systems
Xiaoyu Luo, Chengcheng Zhao, Chongrong Fang, Jianping He
Summary: This paper investigates the problem of false data injection attacks in multi-agent dynamical systems and proposes FDI attack set selection algorithms to maximize the convergence error by finding the optimal subset of compromised agents.
Article
Automation & Control Systems
Nitin K. Singh, Abhisek K. Behera
Summary: In this paper, a twisting observer is proposed for robustly estimating the states of a second-order uncertain system. The observer approximates the unknown sign term for the non-measurable state with a delayed output-based switching function, and achieves the desired steady-state accuracy by controlling the delay parameter. The application of the observer to output feedback stabilization is also discussed.
Article
Automation & Control Systems
Alexander Aleksandrov
Summary: This paper investigates the absolute stability problem for positive Persidskii systems with delay, proposes a special construction method for diagonal Lyapunov-Krasovskii functionals, and derives a criterion for the existence of such functionals guaranteeing the absolute stability, as well as obtaining sufficient conditions for a family of time-delay Persidskii systems to construct a common diagonal Lyapunov-Krasovskii functional. The efficiency of the developed approaches is demonstrated through four examples.
Article
Automation & Control Systems
Noureddine Toumi, Roland Malhame, Jerome Le Ny
Summary: This paper addresses large multi-agent dynamic discrete choice problems using a linear quadratic mean field games framework. The model incorporates the features where agents have to reach a predefined set of possible destinations within a fixed time frame and running costs can become negative to simulate crowd avoidance. An upper bound on the time horizon is derived to prevent agents from escaping to infinity in finite time. The existence of a Nash equilibrium for infinite population and its epsilon-Nash property for a large but finite population are established. Simulations are conducted to explore the model behavior in various scenarios.
Article
Automation & Control Systems
Philippe Schuchert, Vaibhav Gupta, Alireza Karimi
Summary: This paper presents the design of fixed-structure controllers for the As2 and Asw synthesis problem using frequency response data. The minimization of the norm of the transfer function between the exogenous inputs and performance outputs is approximated through a convex optimization problem involving Linear Matrix Inequalities (LMIs). A general controller parametrization is used for continuous and discrete-time controllers with matrix transfer function or state-space representation. Numerical results show that the proposed data-driven method achieves performance equivalent to model-based approaches when a parametric model is available.
Correction
Automation & Control Systems
Zhijun Guo, Gang Chen
Article
Automation & Control Systems
Matteo Della Rossa, Thiago Alves Lima, Marc Jungers, Raphael M. Jungers
Summary: This paper presents new stabilizability conditions for switched linear systems with arbitrary and uncontrollable underlying switching signals. The study focuses on two specific settings: the robust case with completely unknown and unobservable active mode, and the mode-dependent case with controller depending on the current active switching mode. The technical developments are based on graph-theory tools and path-complete Lyapunov functions framework, enabling the design of robust and mode-dependent piecewise linear state-feedback controllers using directed and labeled graphs.
Article
Automation & Control Systems
Elena Petri, Romain Postoyan, Daniele Astolfi, Dragan Nesic, W. P. M. H. (Maurice) Heemels
Summary: This study investigates a scenario where a perturbed nonlinear system transmits its output measurements to a remote observer via a packet-based communication network. By designing both the observer and the local transmission policies, accurate state estimates can be obtained while only sporadically using the communication network.
Article
Automation & Control Systems
Jonas Krook, Robi Malik, Sahar Mohajerani, Martin Fabian
Summary: This paper proposes a method to synthesise controllers for cyber-physical systems subjected to disturbances, such that the controlled system satisfies specifications given as linear temporal logic formulas. The approach constructs a finite-state abstraction of the original system and synthesises a controller for the abstraction. It introduces the robust stutter bisimulation relation to account for disturbances and uncertainty, ensuring that related states have similar effects under the same controller. The paper demonstrates that the existence of a controller for the abstracted system implies the existence of a controller for the original system enforcing the linear temporal logic formula.
Article
Automation & Control Systems
Clement Chahbazian, Karim Dahia, Nicolas Merlinge, Benedicte Winter-Bonnet, Aurelien Blanc, Christian Musso
Summary: The paper derives a recursive formula of the Fisher information matrix on Lie groups and applies it to nonlinear Gaussian systems on Lie groups for testing. The proposed recursive CRLB is consistent with state-of-the-art filters and exhibits representative behavior in estimation errors. This paper provides a simple method to recursively compute the minimal variance of an estimator on matrix Lie groups, which is fundamental for implementing robust algorithms.
Article
Automation & Control Systems
Yiheng Fu, Pouria Ramazi
Summary: This study investigates the characteristics of decision fluctuations in heterogeneous populations and explores the uncertainties in imitation behavior. The findings are important for understanding the bounded rationality nature of imitation behaviors.
Article
Automation & Control Systems
Lars A. L. Janssen, Bart Besselink, Rob H. B. Fey, Nathan van de Wouw
Summary: This paper introduces a mathematical relationship between the accuracy of reduced-order linear-time invariant subsystem models and the stability and accuracy of the resulting reduced-order interconnected linear time-invariant model. This result can be used to directly translate the accuracy characteristics of the reduced-order subsystem models to the accuracy properties of the interconnected reduced-order model, or to translate accuracy requirements on the interconnected system model to accuracy requirements on subsystem models.
Article
Automation & Control Systems
Piyush Gupta, Vaibhav Srivastava
Summary: We study the optimal fidelity selection for a human operator servicing tasks in a queue, considering the trade-off between high-quality service and penalty due to increased queue length. By modeling the operator's cognitive dynamics and task fidelity, we determine the optimal policy and value function numerically, and analyze the structural properties of the optimal fidelity policy.
Article
Automation & Control Systems
Lukas Schwenkel, Alexander Hadorn, Matthias A. Mueller, Frank Allgoewer
Summary: In this work, the authors study economic model predictive control (MPC) in periodic operating conditions. They propose a method to achieve optimality by multiplying the stage cost by a linear discount factor, which is easy to implement and robust against online changes. Under certain assumptions, they prove that the resulting linearly discounted economic MPC achieves optimal asymptotic average performance and guarantees practical asymptotic stability of the optimal periodic orbit.
Article
Automation & Control Systems
Taher Ebrahim, Sankaranarayanan Subramanian, Sebastian Engell
Summary: We propose a robust nonlinear model predictive control algorithm for dynamic systems with mixed degrees of freedom. This algorithm optimizes both continuous and discrete manipulated variables, enhancing closed-loop performance. Our approach relies on a computationally efficient relaxation and integrality restoration strategy and provides sufficient conditions to establish recursive feasibility and guarantee robust closed-loop stability. The effectiveness of the approach is demonstrated through two nonlinear simulation examples.
