Article
Computer Science, Information Systems
Housheng Su, Yali Wu, Liren Zhang, Xia Chen
Summary: This article investigates the problem of structure-free distributed containment control for uncertain underactuated multiple Euler-Lagrange systems (MELSs) considering disturbances using a layered approach. The proposed stratified structure-free containment control method ensures the achievement of the containment control objective and sufficient conditions for structure-free containment control are derived. The effectiveness of the proposed method is verified through a simulation example.
SCIENCE CHINA-INFORMATION SCIENCES
(2023)
Article
Automation & Control Systems
Tairen Sun, Xuexin Zhang, Hongjun Yang, Yongping Pan
Summary: This paper proposes a saturated smooth adaptive controller for regulating a certain type of underactuated Euler-Lagrange systems with modeling uncertainties and control saturations. The controller can semiglobally asymptotically track the desired position without violating control input constraints, and does not require high-order derivatives of positions in its implementation. The control effectiveness is validated through simulations on a two-link compliant robot arm.
Article
Automation & Control Systems
Spandan Roy, Simone Baldi, Petros A. Ioannou
Summary: This paper proposes an adaptive switched control framework to tackle the control problem of underactuated Euler-Lagrange systems with uncertain and switched parameters, without imposing structural constraints. A case study inspired by autonomous vessel operations is used to demonstrate the effectiveness of the proposed approach.
IEEE TRANSACTIONS ON AUTOMATIC CONTROL
(2022)
Article
Mathematics
Nguyen Xuan-Mung, Mehdi Golestani
Summary: This paper investigates the problem of constrained finite-time tracking control of Euler-Lagrange systems subject to system uncertainties and external disturbances. A nonsingular, fast, constrained terminal sliding manifold (NFCTSM) is introduced to deal with the output tracking error constraint and provide desired performance in steady-state and transience. Based on the proposed NFCTSM, a smooth adaptive finite-time control is designed to converge the tracking errors to an arbitrary small region around the origin. The upper bound of the lumped uncertainty is estimated by an adaptive law to avoid the use of the discontinuous signum function.
Article
Mathematics, Interdisciplinary Applications
Saim Ahmed, Ahmad Taher Azar, Mohamed Tounsi, Zeeshan Anjum
Summary: The research provides fixed-time fractional-order control for Euler-Lagrange systems with external disturbances. A new system is developed using the fractional-order fixed-time non-singular terminal sliding mode control (FoFtNTSM) method, which combines the advantages of fractional-order calculus and NTSM to achieve rapid convergence, fixed-time stability, and smooth control inputs. Lyapunov analysis is used to determine the stability of the closed-loop system over a specified time period. Computer simulations demonstrate the performance of the proposed method in the dynamics of the Euler-Lagrange system.
FRACTAL AND FRACTIONAL
(2023)
Article
Computer Science, Information Systems
Babak Salamat, Gerhard Elsbacher
Summary: The article presents a method for controlling the network of underactuated Euler-Lagrange systems, achieving energy efficiency through multi-coordinates transformation and online optimally centralized control, resulting in simple yet powerful state-feedback solutions.
Article
Computer Science, Artificial Intelligence
Yongxu He, Yuxin Zhao
Summary: This article proposes a novel adaptive robust control strategy based on Gaussian processes (GPs) for precise tracking of uncertain Euler-Lagrange (EL) systems with time-varying external disturbances. The strategy utilizes GP regression to obtain a nonparametric uncertainty model and employs adaptive sliding mode control to compensate dynamically using the posterior means of GPs and adjust feedback gains using posterior variances. An adaptive law for updating hyperparameters based on tracking error feedback is presented to improve both tracking control and GP modeling performance. Simulation results validate the effectiveness of the proposed strategy.
IEEE TRANSACTIONS ON NEURAL NETWORKS AND LEARNING SYSTEMS
(2022)
Article
Automation & Control Systems
Xianqing Wu, Kexin Xu
Summary: This article investigates control issues of the translational oscillator with rotational actuator system in the presence of uncertain disturbances. It proposes a nonlinear disturbance observer and a global sliding mode control method for disturbance estimation and stabilization. The proposed methods are compared with existing control methods, showing continuous and global robustness with respect to disturbances.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART I-JOURNAL OF SYSTEMS AND CONTROL ENGINEERING
(2021)
Article
Engineering, Electrical & Electronic
Meng Tao, Xiaoyang Liu, Shao Shao, Jinde Cao
Summary: This brief investigates the predefined-time bipartite consensus of multiple Euler-Lagrange systems with a dynamic leader. A new distributed predefined-time observer is added to estimate the desired velocity of each follower. Then, a new sliding surface and a distributed protocol are constructed to guarantee the networked systems achieve the bipartite consensus within a predefined time. The effectiveness of the new designs is verified through a numerical example with two-link robot arms.
IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS II-EXPRESS BRIEFS
(2022)
Article
Engineering, Aerospace
Babak Salamat, Gerhard Elsbacher
Summary: This article proposes an energy-efficient control method for underactuated robots, achieving optimal control through a centralized stochastic approach. The authors first present a generalized coordinate transformation for underactuated robots, considering their physical properties. Secondly, they propose an optimal control mechanism with the objective of energy efficiency, and demonstrate the feasibility of their approach through robot simulations.
Article
Automation & Control Systems
Nana Wang, Fei Hao
Summary: This article investigates the robust tracking control problem for a class of uncertain Euler-Lagrange systems and proposes an adaptive sliding mode control strategy. By constructing an adaptive parameter estimator and an event-triggering detector in the sensor node, this method reduces the utilization of communication resources and ensures the stability of the system.
INTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL
(2022)
Article
Mathematics, Interdisciplinary Applications
Saim Ahmed, Ahmad Taher Azar, Mohamed Tounsi, Ibraheem Kasim Ibraheem
Summary: This paper presents an adaptive fixed-time fractional integral control for externally disturbed Euler-Lagrange systems. The proposed method combines the benefits of fractional calculus with integral sliding mode control, resulting in fast convergence, smooth control inputs, and fixed-time stability. Simulation results demonstrate the better tracking and convergence performance of the proposed method compared to the adaptive fractional-order sliding mode control scheme.
FRACTAL AND FRACTIONAL
(2023)
Article
Automation & Control Systems
Panlong Tan, Mingwei Sun, Qinglin Sun, Zengqiang Chen
Summary: This study introduces the underactuated characteristics of the rotational-translational actuator system and proposes a new method to overcome this problem by constructing a new actuated state. By using a linear extended state observer, the lumped disturbance of the reconstructed model is estimated and compensated in real-time. Experimental results demonstrate the effectiveness of the proposed controller.
IEEE-ASME TRANSACTIONS ON MECHATRONICS
(2022)
Article
Automation & Control Systems
Spandan Roy, Simone Baldi, Peng Li, Viswa N. Sankaranarayanan
Summary: The article presents an artificial-delay control method with adaptive gains for dealing with nonlinear underactuated systems, focusing on Euler-Lagrange dynamics. The method is shown to be useful for robotics applications, demonstrated through stability and robustness analysis as well as tests on robotic ships and aerial vehicles.
IEEE-ASME TRANSACTIONS ON MECHATRONICS
(2021)
Article
Acoustics
Mohammad-Reza Moghanni-Bavil-Olyaei, Jafar Keighobadi, Ahmad Ghanbari, Angelina Olegovna Zekiy
Summary: This paper proposes a passivity-based hierarchical SM control (PBHSMC) approach to tackle the trajectory tracking issue of a special class of UMSs. The approach ensures global asymptotical convergence and satisfies reaching mode and sliding mode conditions by utilizing feedback passivation and an SMC law. Numerical simulation results demonstrate the superior performance of the proposed PBHSMC scheme compared to the conventional SMO-based HSMC, showing better suppression of unwanted oscillations, lower tracking error and overshoot, shorter settling time, smoother and smaller control efforts, and more accurate estimation of state variables with less chattering.
JOURNAL OF VIBRATION AND CONTROL
(2023)
Article
Mechanics
Qianhong Wu, Sridhar Santhanam, Rungun Nathan, Qiuyun Wang
Article
Engineering, Mechanical
Zenghao Zhu, Rungun Nathan, Qianhong Wu
TRIBOLOGY INTERNATIONAL
(2018)
Article
Thermodynamics
Robert Crawford, Rungun Nathan, Liyun Wang, Qianhong Wu
EXPERIMENTAL THERMAL AND FLUID SCIENCE
(2012)
Article
Mathematics, Applied
Ledjan Qato, Sridhar Santhanam, Gerard F. Jones, Rungun Nathan
FINITE ELEMENTS IN ANALYSIS AND DESIGN
(2014)
Article
Ornithology
Jennifer M. Arnold, Rafael Ordonez, David A. Copeland, Rungun Nathan, Joshua M. Scornavacchi, Donald J. Tyerman, Stephen A. Oswald
JOURNAL OF FIELD ORNITHOLOGY
(2011)
Article
Engineering, Mechanical
Ji Lang, Rungun Nathan, Qianhong Wu
JOURNAL OF FLUIDS ENGINEERING-TRANSACTIONS OF THE ASME
(2019)
Article
Mechanics
Qiuyun Wang, Zenghao Zhu, Rungun Nathan, Qianhong Wu
EUROPEAN JOURNAL OF MECHANICS B-FLUIDS
(2019)
Article
Engineering, Mechanical
Ji Lang, Rungun Nathan, Qianhong Wu
TRIBOLOGY INTERNATIONAL
(2019)
Article
Engineering, Mechanical
Zenghao Zhu, Rungun Nathan, Qianhong Wu
TRIBOLOGY INTERNATIONAL
(2019)
Article
Engineering, Chemical
Zenghao Zhu, Rungun Nathan, Qianhong Wu
Article
Mechanics
Ji Lang, Rungun Nathan, Qianhong Wu
Summary: The study reveals that soft matter like egg yolk is sensitive to rotational impacts but not to translational impacts when in a liquid environment. The centrifugal force and the shape of the membrane play critical roles in causing deformation of the soft object during decelerating-rotational impacts. This research provides insight into the fundamental physics of motion and deformation of membrane-bound soft objects in response to external impacts.
Article
Mechanics
Ji Lang, Rungun Nathan, Dong Zhou, Xuewei Zhang, Bo Li, Qianhong Wu
Summary: Using an artificial transparent head surrogate and high-speed photography, this study uncovered the formation and collapse of cavitation bubbles near contrecoup regions during sudden translational head impact, resulting in brain surface damage and shock wave transmission through brain matter. The findings suggest that current brain injury criteria may underestimate the risk posed by head collisions.
Article
Thermodynamics
Qiuyun Wang, Rungun Nathan, Qianhong Wu
JOURNAL OF POROUS MEDIA
(2019)
Article
Mechanics
T. Gacka, Z. Zhu, R. Crawford, R. Nathan, Q. Wu
JOURNAL OF FLUID MECHANICS
(2017)
Proceedings Paper
Education & Educational Research
Somnath Chattopadhyay, Rungun Nathan
2013 ASEE ANNUAL CONFERENCE
(2013)
Article
Mathematics, Applied
Torsten Lindstrom
Summary: This paper aims to analyze the mechanism for the interplay of deterministic and stochastic models in contagious diseases. Deterministic models usually predict global stability, while stochastic models exhibit oscillatory patterns. The study found that evolution maximizes the infectiousness of diseases and discussed the relationship between herd immunity concept and vaccination programs.
NONLINEAR ANALYSIS-REAL WORLD APPLICATIONS
(2024)
Article
Mathematics, Applied
Dong Deng, Hongxun Wei
Summary: This paper investigates the existence and nonexistence of time-periodic traveling waves for a diffusive influenza model with treatment and seasonality. By utilizing the next generation operator theory and Schauder's fixed point theorem, the conditions for the existence of time-periodic traveling wave solutions are obtained, along with the proof of nonexistence in certain cases and exponential decay for waves with critical speed.
NONLINEAR ANALYSIS-REAL WORLD APPLICATIONS
(2024)
Article
Mathematics, Applied
Xuan Ma, Yating Wang
Summary: In this paper, the dynamics of a rarefied gas in a finite channel is studied, specifically focusing on the phenomenon of Couette flow. The authors demonstrate that the unsteady Couette flow for the Boltzmann equation converges to a 1D steady state and derive the exponential time decay rate. The analysis holds for all hard potentials.
NONLINEAR ANALYSIS-REAL WORLD APPLICATIONS
(2024)
Article
Mathematics, Applied
Meng Zhao
Summary: In this paper, a reaction-diffusion waterborne pathogen model with free boundary is studied. The existence of a unique global solution is proved, and the longtime behavior is analyzed through a spreading-vanishing dichotomy. Sharp criteria for spreading and vanishing are obtained, which differs from the previous results by Zhou et al. (2018) stating that the epidemic will spread when the basic reproduction number is larger than 1.
NONLINEAR ANALYSIS-REAL WORLD APPLICATIONS
(2024)
Article
Mathematics, Applied
Gulsemay Yigit, Wakil Sarfaraz, Raquel Barreira, Anotida Madzvamuse
Summary: This study presents theoretical considerations and analysis of the effects of circular geometry on the stability of reaction-diffusion systems with linear cross-diffusion on circular domains. The highlights include deriving necessary and sufficient conditions for cross-diffusion driven instability and computing parameter spaces for pattern formation. Finite element simulations are also conducted to support the theoretical findings. The study suggests that linear cross-diffusion coupled with reaction-diffusion theory is a promising mechanism for pattern formation.
NONLINEAR ANALYSIS-REAL WORLD APPLICATIONS
(2024)
Article
Mathematics, Applied
Miaoqing Tian, Lili Han, Xiao He, Sining Zheng
Summary: This paper studies the attraction-repulsion chemotaxis system of two-species with two chemical substances. The behavior of solutions is determined by the interactions among diffusion, attraction, repulsion, logistic sources, and nonlinear productions in the system. The paper provides conditions for the global boundedness of solutions.
NONLINEAR ANALYSIS-REAL WORLD APPLICATIONS
(2024)
Article
Mathematics, Applied
Michal Borowski, Iwona Chlebicka, Blazej Miasojedow
Summary: This article provides a short proof of a sharp rearrangement estimate for a generalized version of a potential of Wolff-Havin-Maz'ya type. It characterizes the potentials that are bounded between rearrangement invariant spaces via a one-dimensional inequality of Hardy-type. By controlling very weak solutions to a broad class of quasilinear elliptic PDEs of non-standard growth, the special case of the mentioned potential infers the local regularity properties of solutions in rearrangement invariant spaces for prescribed classes of data.
NONLINEAR ANALYSIS-REAL WORLD APPLICATIONS
(2024)
Article
Mathematics, Applied
Young-Pil Choi, Jinwook Jung
Summary: This study investigates the global-in-time well-posedness of the pressureless Euler-alignment system with singular communication weights. A global-in-time bounded solution is constructed using the method of characteristics, and uniqueness is obtained via optimal transport techniques.
NONLINEAR ANALYSIS-REAL WORLD APPLICATIONS
(2024)
Article
Mathematics, Applied
Chuangxia Huang, Xiaodan Ding
Summary: In this paper, a diffusive Mackey-Glass model with distinct diapause and developmental delays is proposed based on the diapause effect. Some sufficient conditions for the existence of traveling wave fronts are obtained by constructing appropriate upper and lower solutions and employing inequality techniques. Two numerical examples are provided to demonstrate the reliability and feasibility of the proposed model.
NONLINEAR ANALYSIS-REAL WORLD APPLICATIONS
(2024)
Article
Mathematics, Applied
Hongxing Zhao
Summary: This paper investigates the flow of fluid through a thin corrugated domain saturated with porous medium, governed by the Navier-Stokes model. Asymptotic models are derived by comparing the relation between a and the size of the periodic cylinders. The homogenization technique based on the generalized Poincare inequality is used to prove the main results.
NONLINEAR ANALYSIS-REAL WORLD APPLICATIONS
(2024)
Article
Mathematics, Applied
Evgenii S. Baranovskii, Roman V. Brizitskii, Zhanna Yu. Saritskaia
Summary: This paper proves the solvability of optimal control problems for both weak and strong solutions of a boundary value problem associated with the nonlinear reaction-diffusion-convection equation with variable coefficients. In the case of strong solutions, the requirements for smoothness of the multiplicative control are reduced. The study of extremal problems is based on the proof of solvability of the corresponding boundary value problems and the qualitative analysis of their solution properties. The paper establishes existence results for weak solutions with large data, the maximum principle, and local existence and uniqueness of a strong solution. Furthermore, an optimal feedback control problem is considered, and sufficient conditions for its solvability in the class of weak solutions are obtained using methods of the theory of topological degree for set-valued perturbations.
NONLINEAR ANALYSIS-REAL WORLD APPLICATIONS
(2024)
Article
Mathematics, Applied
Antonia Chinni, Beatrice Di Bella, Petru Jebelean, Calin Serban
Summary: This article focuses on the multiplicity of solutions for differential inclusions involving the p-biharmonic operator, applying a variational approach and relying on non-smooth critical point theory.
NONLINEAR ANALYSIS-REAL WORLD APPLICATIONS
(2024)
Article
Mathematics, Applied
Zhong Tan, Saiguo Xu
Summary: This paper investigates the Rayleigh-Taylor instability of three-dimensional inhomogeneous incompressible Euler equations with damping in a horizontal slab. It is shown that the Euler system with damping is nonlinearly unstable around the given steady state if the steady density profile is non-monotonous along the height. A new variational structure is developed to construct the growing mode solution, and the difficulty in proving the sharp exponential growth rate is overcome by exploiting the structures in linearized Euler equations. Combined with error estimates and a standard bootstrapping argument, the nonlinear instability is established.
NONLINEAR ANALYSIS-REAL WORLD APPLICATIONS
(2024)
Article
Mathematics, Applied
Samuele Ricco, Andrea Torricelli
Summary: This paper presents a solution method for the autonomous obstacle problem, finding a necessary condition for the extremality of the unique solution using a primal-dual formulation. The proof is based on classical arguments of Convex Analysis and Calculus of Variations' techniques.
NONLINEAR ANALYSIS-REAL WORLD APPLICATIONS
(2024)
Article
Mathematics, Applied
Shuxin Ge, Rong Yuan, Xiaofeng Zhang
Summary: This paper studies an initial boundary value problem for a nonlocal parabolic equation with a diffusion term and convex-concave nonlinearities. By establishing the Lq-estimate and analyzing its energy, the existence of global solutions is proven and some blow-up conditions are obtained. Using the variational structure of the problem, the Mountain-pass theorem is utilized to demonstrate the existence of nontrivial steady-state solutions. The dynamical behavior of global solutions with relatively compact trajectories in H01 (Ω) is also established, showing uniform convergence to a non-zero steady state after a long time due to the energy functional satisfying the P.S. condition. Finally, an unstable steady states sequence is derived using another minimax theorem.
NONLINEAR ANALYSIS-REAL WORLD APPLICATIONS
(2024)
