scholarly journals Input-to-State Stability of Variable Impedance Control for Robotic Manipulator

2020 ◽  
Vol 10 (4) ◽  
pp. 1271 ◽  
Author(s):  
Junho Park ◽  
Youngjin Choi
Keyword(s):  
Stiffness Matrix ◽  
High Performance ◽  
Impedance Control ◽  
Time Derivative ◽  
Sufficient Conditions ◽  
Time Varying ◽  
Impedance Model ◽  
Simulation Results ◽  
The Given ◽  
Contact Tasks

Variable impedance control has been required to perform a variety of interactive tasks in contact with environments. In some cases, the time-varying stiffness matrix of the impedance model can be used to achieve high performance for uneven contact tasks. In the paper, two sufficient conditions are proposed to ensure the input-to-state stability (ISS) irrespective of time-varying stiffness. Furthermore, the update rule of the stiffness is also suggested in such a way that the asymptotic stability is guaranteed under certain region conditions. Even when the update rule is not applied, the ISS is at least assured. In other words, the error is always bounded only if the external force/torque is bounded. In detail, two sufficient conditions offer the lower bound of stiffness and the upper bound of its time derivative. Simulation results show that the ISS of variable impedance control is achieved if the proposed sufficient conditions are satisfied. Also, we can confirm the asymptotic behavior in the simulation when the stiffness is updated according to the given rule.

scholarly journals Time-Varying Impedance Control of Port Hamiltonian System with a New Energy-Storing Tank

Complexity ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Min Zheng ◽  
Tangqing Yuan ◽  
Tao Huang
Keyword(s):  
Control Method ◽  
Impedance Control ◽  
Conservative System ◽  
Time Varying ◽  
Control Performance ◽  
Singularity Problem ◽  
Numerical Examples ◽  
New Energy ◽  
Simulation Results ◽  
New Framework

In order to guarantee the passivity of a kind of conservative system, the port Hamiltonian framework combined with a new energy tank is proposed in this paper. A time-varying impedance controller is designed based on this new framework. The time-varying impedance control method is an extension of conventional impedance control and overcomes the singularity problem that existed in the traditional form of energy tank. The validity of the controller designed in this paper is shown by numerical examples. The simulation results show that the proposed controller can not only eliminate the singularity problem but can also improve the control performance.

Adaptive Synchronization in Unknown Stochastic Chaotic Neural Networks with Mixed Time-Varying Delays

2011 ◽  
pp. 289-313
Author(s):  
Jian-an Fang ◽  
Yang Tang
Keyword(s):  
Neural Networks ◽  
Sufficient Conditions ◽  
Stochastic Perturbation ◽  
Adaptive Synchronization ◽  
Output Coupling ◽  
Time Varying ◽  
Connection Weight ◽  
Chaotic Neural Networks ◽  
Simulation Results ◽  
Feedback Techniques

Neural networks (NNs) have been useful in many fields, such as pattern recognition, image processing etc. Recently, synchronization of chaotic neural networks (CNNs) has drawn increasing attention due to the high security of neural networks. In this chapter, the problem of synchronization and parameter identification for a class of chaotic neural networks with stochastic perturbation via state and output coupling, which involve both the discrete and distributed time-varying delays has been investigated. Using adaptive feedback techniques, several sufficient conditions have been derived to ensure the synchronization of stochastic chaotic neural networks. Moreover, all the connection weight matrices can be estimated while the lag synchronization and complete synchronization is achieved in mean square at the same time. The corresponding simulation results are given to show the effectiveness of the proposed method.

scholarly journals Sampled-Data-Based Adaptive Group Synchronization of Second-Order Nonlinear Complex Dynamical Networks with Time-Varying Delays

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Bo Liu ◽  
Jiahui Bai ◽  
Yue Zhao ◽  
Chao Liu ◽  
Xuemin Yan ◽  
...  
Keyword(s):  
Adaptive Strategy ◽  
Second Order ◽  
Complex Dynamical Networks ◽  
Time Varying ◽  
Sampled Data ◽  
Dynamical Networks ◽  
Coupling Strengths ◽  
Simulation Results ◽  
Group Synchronization ◽  
The Given

This paper studies the adaptive group synchronization of second-order nonlinear complex dynamical networks with sampled-data and time-varying delays by designing a new adaptive strategy to feedback gains and coupling strengths. According to Lyapunov stability properties, it is shown that the agents of subgroups can converge the given synchronous states, respectively, under some conditions on the sampled period. Moreover, some simulation results are given.

scholarly journals Stability and Stabilization for Polytopic LPV Systems with Parameter-Varying Time Delays

2019 ◽  
Vol 2019 ◽  
pp. 1-12
Author(s):  
Fu Chen ◽  
Shugui Kang ◽  
Fangyuan Li
Keyword(s):  
Time Delays ◽  
Time Derivative ◽  
Sufficient Conditions ◽  
Linear Matrix ◽  
Time Varying ◽  
Lpv Systems ◽  
Stability And Stabilization ◽  
Parameter Varying ◽  
Conditions Of Stability ◽  
Delay Dependent

In this paper, we deal with the problem of stability and stabilization for linear parameter-varying (LPV) systems with time-varying time delays. The uncertain parameters are assumed to reside in a polytope with bounded variation rates. Being main difference from the existing achievements, the representation of the time derivative of the time-varying parameter is under a polytopic structure. Based on the new representation, delay-dependent sufficient conditions of stability and stabilization are, respectively, formulated in terms of linear matrix inequalities (LMI). Simulation examples are then provided to confirm the effectiveness of the given approach.

scholarly journals CALCINATION OF FINELY DISPERSED LIMESTONE IN A FLUIDIZED BED OF INERT MATERIAL. 2. NUMERICAL SIMULATION RESULTS

2019 ◽  
pp. 45-49
Author(s):  
V.V. Kolesnyk ◽  
V.M. Orlyk ◽  
Yu.I. Khvastukhin ◽  
K.P. Kostohryz ◽  
V.A. Zhaivoronok
Keyword(s):  
Gas Phase ◽  
Fluidized Bed ◽  
Process Design ◽  
High Performance ◽  
Pore Diameter ◽  
Design Stage ◽  
Inert Material ◽  
Simulation Results ◽  
The Given

The results of numerical experiments concerning the process of calcination of small grained limestone particles in contact with the gas phase of a fluidized bed of inert grainy material for obtaining a high-performance sorbent are given. The character of the change of the basic qualitative parameters of the obtained sorbent – droopiness, surface area, mass is presented depending on the time of residence of the initial limestones with a diameter of 80–200 nm with initial porosity e0 = 0,03–0,1 and pore diameter dpor = 3,84–17 nm in the high-reaction zone when the temperature of the gas phase of the fluidized bed is changed within 900–1200 °С. The obtained results allow further in the design stage to determine the optimum hardware and process design of the process of calcination, depending on the initial parameters of the limestone, which will provide the desired quality of the limestone sorbent in accordance with the given power installation. Bibl. 1, Fig. 10.

scholarly journals Generalized Mutual Synchronization between Two Controlled Interdependent Networks

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Quan Xu ◽  
Shengxian Zhuang ◽  
Dan Hu ◽  
Yingfeng Zeng ◽  
Jian Xiao
Keyword(s):  
Lyapunov Functions ◽  
Sufficient Conditions ◽  
Control Technique ◽  
Time Varying ◽  
State Variables ◽  
Mutual Synchronization ◽  
Interdependent Networks ◽  
Synchronization Errors ◽  
Simulation Results ◽  
Theoretical Results

This paper mainly focuses on the generalized mutual synchronization between two controlled interdependent networks. First, we propose the general model of controlled interdependent networksAandBwith time-varying internetwork delays coupling. Then, by constructing Lyapunov functions and utilizing adaptive control technique, some sufficient conditions are established to ensure that the mutual synchronization errors between the state variables of networksAandBcan asymptotically converge to zero. Finally, two numerical examples are given to illustrate the effectiveness of the theoretical results and to explore potential application in future smart grid. The simulation results also show how interdependent topologies and internetwork coupling delays influence the mutual synchronizability, which help to design interdependent networks with optimal mutual synchronizability.

scholarly journals Four-Channel Teleoperation with Time-Varying Delays and Disturbance Observers

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Emma Delgado ◽  
Pablo Falcón ◽  
Miguel Díaz-Cacho ◽  
Antonio Barreiro
Keyword(s):  
Robust Stability ◽  
Time Derivative ◽  
Singular Values ◽  
Time Varying ◽  
Communication Delays ◽  
Force Measurements ◽  
Generic Framework ◽  
Plant Modelling ◽  
Simulation Results ◽  
New Feature

This paper addresses the robust stability of teleoperated systems under the four-channel architecture, affected by time-varying communication delays and using disturbance observers. It is based on our previous work which provides a framework for robust stability against delays with bounded variation and a bounded time-derivative, using structured singular values (SSV). The main new feature here is the inclusion of disturbance observers (DOBs). The DOB concept is well-documented and relevant to many applications, since only position (but not force) measurements are usually available. In this paper, we adapt two DOBs (master and slave) to our generic framework, by representing them as stable, fast filters affected by the uncertainty in the plant modelling. Our main result is an SSV test to verify robust stability. The simulation results confirm the usefulness of this approach.

On the Stability of Second Order Time Varying Linear Systems

2005 ◽  
Vol 128 (3) ◽  
pp. 408-410 ◽  
Author(s):  
M. Tadi
Keyword(s):  
Asymptotic Stability ◽  
Linear Systems ◽  
Stiffness Matrix ◽  
Linear Time ◽  
Sufficient Conditions ◽  
Second Order ◽  
Time Varying ◽  
The Stability ◽  
Second Order Systems

This note considers the stability of linear time varying second order systems. It studies the case where the stiffness matrix is a function of time. It provides sufficient conditions for stability and asymptotic stability of the system provided that certain conditions on the stiffness matrix are satisfied.

Global synchronization for hybrid coupled neural networks with interval time-varying delays: A matrix-based quadratic convex approach

2016 ◽  
Vol 10 (02) ◽  
pp. 1750025
Author(s):  
Thongchai Botmart ◽  
Narongsak Yotha ◽  
Kanit Mukdasai ◽  
Supreecha Wongaree
Keyword(s):  
Neural Networks ◽  
Time Derivative ◽  
Sufficient Conditions ◽  
Upper And Lower Bounds ◽  
Linear Matrix ◽  
Time Varying ◽  
Global Synchronization ◽  
Interval Time ◽  
Coupled Neural Networks ◽  
Time Varying Delay

This paper is concerned with the global synchronization problems for coupled neural networks (NNs) with hybrid coupling and interval time-varying delays. An appropriate Lyapunov–Krasovskii functional (LKF) and Kronecker product properties are used to form some new delay-dependent synchronization conditions in terms of linear matrix inequalities. A matrix-based quadratic convex approach introduce for sufficient conditions to ensure global synchronization where the time-varying delay is continuous uniformly bounded and its time-derivative bounded by upper and lower bounds. Simulation results are given to show the effectiveness and benefits of the proposed methods.

scholarly journals 3D Simulation-Based Acoustic Wave Resonator Analysis and Validation Using Novel Finite Element Method Software

Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2715
Author(s):  
Ruth Yadira Vidana Morales ◽  
Susana Ortega Cisneros ◽  
Jose Rodrigo Camacho Perez ◽  
Federico Sandoval Ibarra ◽  
Ricardo Casas Carrillo
Keyword(s):  
Finite Element ◽  
High Performance ◽  
Cloud Services ◽  
3D Simulation ◽  
3D Simulations ◽  
Acoustic Resonators ◽  
Analysis And Design ◽  
Wave Resonator ◽  
Film Bulk ◽  
Simulation Results

This work illustrates the analysis of Film Bulk Acoustic Resonators (FBAR) using 3D Finite Element (FEM) simulations with the software OnScale in order to predict and improve resonator performance and quality before manufacturing. This kind of analysis minimizes manufacturing cycles by reducing design time with 3D simulations running on High-Performance Computing (HPC) cloud services. It also enables the identification of manufacturing effects on device performance. The simulation results are compared and validated with a manufactured FBAR device, previously reported, to further highlight the usefulness and advantages of the 3D simulations-based design process. In the 3D simulation results, some analysis challenges, like boundary condition definitions, mesh tuning, loss source tracing, and device quality estimations, were studied. Hence, it is possible to highlight that modern FEM solvers, like OnScale enable unprecedented FBAR analysis and design optimization.

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