scholarly journals On the Controllability of Discrete-Time Leader-Follower Multiagent Systems with Two-Time-Scale and Heterogeneous Features

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Mengqi Gu ◽  
Guo-Ping Jiang
Keyword(s):  
Singular Perturbation ◽  
Multiagent Systems ◽  
Discrete Time ◽  
Time Scale ◽  
Perturbation Parameter ◽  
Fast Time ◽  
Singular Perturbation Method ◽  
Difference Systems ◽  
Heterogeneous Features ◽  
Classical Control

This paper investigates the controllability of discrete-time leader-follower multiagent systems (MASs) with two-time-scale and heterogeneous features, motivated by the fact that many real systems are operating in discrete-time. In this study, singularly perturbed difference systems are used to model the two-time-scale heterogeneous discrete-time MASs. To avoid the ill-posedness problem caused by the singular perturbation parameter when using the classical control theory to study the model, the singular perturbation method was first applied to decompose the system into two subsystems with slow-time-scale and fast-time-scale feature. Then, from the perspective of algebra and graph theory, several easier-to-use controllability criteria for the related MASs are proposed. Finally, the effectiveness of the main results is verified by simulation.

Controllability of Two-Time-Scale Discrete-Time Multiagent Systems

2020 ◽  
Vol 50 (4) ◽  
pp. 1440-1449 ◽  
Author(s):  
Housheng Su ◽  
Mingkang Long ◽  
Zhigang Zeng
Keyword(s):  
Multiagent Systems ◽  
Discrete Time ◽  
Time Scale

scholarly journals Additive fault tolerant control of nonlinear singularly perturbed systems against actuator fault

2017 ◽  
Vol 68 (1) ◽  
pp. 68-73 ◽  
Author(s):  
Adel Tellili ◽  
Aymen Elghoul ◽  
Mohamed Naceur Abdelkrim
Keyword(s):  
Singular Perturbation ◽  
Fault Tolerant ◽  
Fault Tolerant Control ◽  
Perturbation Parameter ◽  
Singularly Perturbed ◽  
Actuator Faults ◽  
Singularly Perturbed Systems ◽  
Singular Perturbation Method ◽  
Numerical Application ◽  
Perturbed Systems

AbstractThis paper presents the design of an additive fault tolerant control for nonlinear time-invariant singularly perturbed systems against actuator faults based on Lyapunov redesign principle. The overall system is reduced into subsystems with fast and slow dynamic behavior using singular perturbation method. The time scale reduction is carried out when the singular perturbation parameter is set to zero, thus avoiding the numerical stiffness due to the interaction of two different dynamics. The fault tolerant controller is computed in two steps. First, a nominal composite controller is designed using the reduced subsystems. Secondly, an additive part is combined with the basic controller to overcome the fault effect. The derived ε - independent controller guarantees asymptotic stability despite the presence of actuator faults. The Lyapunov stability theory is used to prove the stability provided the singular perturbation parameter is sufficiently small. The theoretical results are simulated using a numerical application.

scholarly journals Reconfigurable control of flexible joint robot with actuator fault and uncertainty

2019 ◽  
Vol 70 (2) ◽  
pp. 130-137
Author(s):  
Aymen Elghoul ◽  
Adel Tellili ◽  
Mohamed Naceur Abdelkrim
Keyword(s):  
Singular Perturbation ◽  
Perturbation Method ◽  
Fault Tolerant ◽  
Robot Manipulator ◽  
Fault Tolerant Control ◽  
Uncertain System ◽  
Perturbation Parameter ◽  
Actuator Fault ◽  
Singular Perturbation Method ◽  
Flexible Joint

Abstract This paper presents the fault tolerant control (FTC) of a flexible joint robot using singular perturbation method in order to compensate for the lost performance due to the occurrence of actuator fault and the uncertainty. This FTC is based on Lyapunov redesign principle. The singular perturbation method is used to reduce the dynamic model of the flexible joint robot in a fast and slow subsystem. The time scale reduction of the flexible joint model is carried out when their joint stiffness is large enough and the singular perturbation parameter is set to zero. The fault-tolerant control structure in this paper is based on two parts. The first term described the composite control for the system without defect and without uncertainty which represents the sum between slow and fast controllers. While the second term of the fault tolerant command describes additive control designed to compensate for the fault effect of the actuator on the uncertain system. The additive approach is based on the Lyapunov theorem, which guarantees asymptotic stability despite the presence of actuator defects and the parametric uncertainty. The theoretical results are applied on a robot manipulator with a single flexible joint.

Reconfigurable Control of Two-Time Scale Systems in Presence of Additive Faults

2015 ◽  
Vol 44 (4) ◽  
pp. 357-366 ◽  
Author(s):  
Adel Tellili ◽  
Nouceyba Abdelkrim ◽  
Amina Challouf ◽  
Mohamed Naceur Abdelkrim
Keyword(s):  
Feedback Control ◽  
Singular Perturbation ◽  
Control Method ◽  
Perturbation Parameter ◽  
State Feedback Control ◽  
Sensor Faults ◽  
Singularly Perturbed Systems ◽  
Singular Perturbation Method ◽  
External Disturbances ◽  
Control Scheme

This work presents an adaptive approach for fault tolerant control of singularly perturbed systems, where both actuator and sensor faults are examined in presence of external disturbances. For sensor faults, an adaptive controller is designed based on an output-feedback control scheme. The feedback controller gain is determined in order to stabilize the closed-loop system in the fault free case and vanishing disturbance, while the additive gain is updated using an adaptive law to compensate for the sensor faults and the external disturbances. To correct the actuator faults, a state-feedback control method based on adaptive mechanism is considered. The both proposed controllers depend on the singular perturbation parameter ε leading to ill-conditioned problems. A well-posed problem is obtained by simplifying the Lyapunov equations and subsequently the controllers using the singular perturbation method and the reduced subsystems yielding to an ε-independent controller. The control scheme, designed based on the Lyapunov stability theory, guarantees asymptotic stability in presence of additive faults and external disturbances provided the singular perturbation parameter is sufficiently small. Finally, a numerical example is presented to demonstrate the effectiveness of the obtained results.DOI: http://dx.doi.org/10.5755/j01.itc.44.4.8532

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