Article
Computer Science, Artificial Intelligence
Tong Yang, Ning Sun, Zhuoqing Liu, Yongchun Fang
Summary: This article designs an adaptive tracking controller for underactuated robotic systems to achieve exponential convergence results and compensate for unknown dynamics/disturbances using a data-driven concurrent learning method. It also utilizes a disturbance judgment mechanism to eliminate the detrimental impacts of external disturbances. Theoretical analysis and hardware experiment results demonstrate the effectiveness of the designed controller, which ensures transient performance and exponential convergence speed for unactuated states and achieves exponential tracking for actuated motions.
IEEE TRANSACTIONS ON NEURAL NETWORKS AND LEARNING SYSTEMS
(2023)
Article
Automation & Control Systems
Rosana C. B. Rego, Fabio Meneghetti U. de Araujo
Summary: Learning-based neural network control methods can be applied to handle complex nonlinear systems, providing better solutions and stability guarantees.
ENGINEERING APPLICATIONS OF ARTIFICIAL INTELLIGENCE
(2022)
Article
Engineering, Electrical & Electronic
Tianqiao Zhao, Jianhui Wang, Xiaonan Lu, Yuhua Du
Summary: The paper proposes a novel control framework for power system control and stability problems leveraging a learning-based approach, which ensures provable system stability and simplifies control design for complex power systems.
IEEE TRANSACTIONS ON POWER SYSTEMS
(2022)
Article
Automation & Control Systems
Biao Lu, Yongchun Fang
Summary: The loss of actuators poses challenges to the control of underactuated systems, as unactuated degrees of freedom must be indirectly stabilized through appropriate regulation of actuated ones. A nonlinear gain-adapting controller is proposed to enhance state couplings and improve system performance and robustness in the face of disturbances. The proposed method imposes few requirements on system configuration, making it more convenient for practical application.
Article
Automation & Control Systems
Jeronimo Moyron, Javier Moreno-Valenzuela, Jesus Sandoval
Summary: This document discusses the important subject of the local or global asymptotic stability of the closed-loop system equilibrium point in the position control of robot manipulators, particularly when an integral action is added to the control loop. While global nonlinear proportional-integral-derivative (PID) controllers have been introduced for rigid joint robot manipulators, it is much more challenging to design and analyze such controllers for flexible joint robot manipulators, with only local asymptotic stability results reported. Thus, a novel global regulator for flexible joint robots is presented here, which considers a nonlinear integral action and uses a estimator subsystem to replace motor velocity measurements. The proposed nonlinear PID-type controller establishes conditions on the controller gains based on closed-loop system analysis, leading to global asymptotic stability. Experimental results on a two degrees-of-freedom serial flexible joint robot are also presented and discussed.
IEEE TRANSACTIONS ON AUTOMATIC CONTROL
(2023)
Article
Automation & Control Systems
Tianliang Zhang, Feiqi Deng
Summary: This article corrects some errors in Definitions 3.2 and 4.1 and Theorem 4.1. of the reference [1].
IEEE TRANSACTIONS ON AUTOMATIC CONTROL
(2021)
Article
Automation & Control Systems
Pavel Osinenko, Grigory Yaremenko, Georgiy Malaniya
Summary: The control Lyapunov function is a key tool for stabilization and extends the concept of a Lyapunov function to controlled systems. Most control Lyapunov functions are nonsmooth, including in nonholonomic systems like wheeled robots and cars. This work generalizes existing stabilization frameworks to the stochastic case, considering random noise acting on the system. The main result is a theorem stating that if a control Lyapunov function exists, the stochastic dynamical system can be practically stabilized in the sample-and-hold mode using a specific control method.
IEEE TRANSACTIONS ON AUTOMATIC CONTROL
(2023)
Article
Automation & Control Systems
Tong Yang, He Chen, Ning Sun, Yongchun Fang
Summary: A new adaptive output-feedback controller is designed for a class of uncertain underactuated systems, ensuring all state variables are kept within preset ranges and converge to desired values by introducing a coupling term of actuated and unactuated constraints. This research provides the first solution to achieve accurate motion control and state constraints without exact model knowledge and velocity feedback, proving meaningful both theoretically and practically through detailed theoretical analysis and experimental validations on underactuated overhead and rotary cranes.
IEEE TRANSACTIONS ON SYSTEMS MAN CYBERNETICS-SYSTEMS
(2022)
Article
Mathematics
Meirbek Moldabekov, Anna Sukhenko, Yerkin Orazaly, Alisher Aden
Summary: This study aims to analyze the nonlinear dynamics of a satellite attitude control system equipped with reaction wheels and a PD controller. Based on the angular momentum conservation theorem, the nonlinear equations of the attitude control system dynamics are presented as a linear system of differential equations with time-varying parameters. The asymptotic properties of the angular momentum of a mechanical system including a satellite and reaction wheels are investigated. The dependencies of the dynamic parameters of the attitude control system on the constant parameters of the ultimate system of linear differential equations enable the application of proven engineering methods for stability analysis and control law synthesis.
Article
Chemistry, Multidisciplinary
Grzegorz Gembalczyk, Piotr Gierlak, Slawomir Duda
Summary: This article discusses the stability analysis of a control system for a dynamic body weight support system in a rehabilitation device for the re-education of human gait. It presents a physical model of the device and methodology used to verify the stability of the control system.
APPLIED SCIENCES-BASEL
(2021)
Article
Automation & Control Systems
Alexander Aleksandrov, Denis Efimov
Summary: This paper studies a mechanical system under strongly nonlinear potential and dissipative forces, considering nonlinear nonstationary perturbations with zero mean values. By proposing a special construction of Lyapunov function, the conditions are found under which the perturbations do not affect the asymptotic stability of the system's equilibrium position. These conditions include the requirements for the asymptotic stability of the disturbance-free system and the relationships between the nonlinearity orders of the potential and dissipative forces. The developed approach is also extended to the problem of monoaxial stabilization of a rigid body.
Article
Acoustics
Amir Alihosseini, Nima Mahdian Dehkordi, Mohammadreza Sajjadi
Summary: In this paper, a novel free chattering robust nonlinear sliding mode control based on the Lyapunov theory for underactuated two-wheels mobile robots is proposed. The salient features of the proposed control method are: (1) considering the full dynamics of the system, disturbances, and uncertainties; (2) not considering the small signal model of the system that leads to the large signal instability; and (3) resulting in less costs, least chattering, easy implementation, and no stability issues. The proposed nonlinear controller is designed based on Lyapunov and Lassalle theory. Moreover, the proposed controller is shown to be robust against disturbances and uncertainties.
JOURNAL OF VIBRATION AND CONTROL
(2023)
Article
Robotics
Gerasimos Rigatos, Nikolaos Zervos, Pierluigi Siano, Masoud Abbaszadeh, Jorge Pomares, Patrice Wira
Summary: This article proposes a nonlinear optimal control method for underactuated power-line inspection robots, achieving global stability through Lyapunov analysis and solving algebraic Riccati equations to determine feedback gains. The method improves the autonomy and operational capacity of robotic systems by minimizing energy dispersion and ensuring reliable functioning in underactuation conditions.
Article
Mathematics, Applied
Yiheng Wei, Linlin Zhao, Yidong Wei, Jinde Cao
Summary: This paper addresses the issue of stability analysis of nabla fractional order systems, which is crucial when applying fractional calculus to control problems in engineering applications. In contrast to the conventional Lyapunov theorem, the newly developed theorems presented here are practical and versatile. Firstly, two enhanced stability criteria are established for Mittag-Leffler stability and asymptotic stability, respectively. Subsequently, Lyapunov theorems based on class K functions are derived to assess boundedness and attractiveness. Finally, illustrative examples are also provided to substantiate the theoretical results. & COPY; 2023 Elsevier B.V. All rights reserved.
COMMUNICATIONS IN NONLINEAR SCIENCE AND NUMERICAL SIMULATION
(2023)
Article
Automation & Control Systems
Jingjing Jiangand, Alessandro Astolfi
Summary: A novel method inspired by back-stepping, called underactuated back-stepping, is introduced to solve the stabilization problem for a class of nonlinear systems, specifically underactuated mechanical systems. The properties of resulting closed-loop systems are studied in detail, and case studies are provided to demonstrate the effectiveness of the proposed method.
IEEE TRANSACTIONS ON AUTOMATIC CONTROL
(2021)
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.