The stability of AGC systems with real parameter uncertainties and communication delays

2012 ◽  
Author(s):  
M. Liu ◽  
H. An ◽  
B. Hao ◽  
Z. Wang ◽  
D. Gan ◽  
...  
Keyword(s):  
Real Parameter ◽  
Communication Delays ◽  
Parameter Uncertainties ◽  
The Stability

Reduced-order observer-based consensus control of linear multi-agent systems over directed networks with nonuniform communication delays

2020 ◽  
pp. 014233122093430
Author(s):  
Qiuzhen Wang ◽  
Jiangping Hu ◽  
Yiyi Zhao ◽  
Bijoy Kumar Ghosh
Keyword(s):  
Time Varying ◽  
Communication Delays ◽  
Multi Agent Systems ◽  
Consensus Control ◽  
Reduced Order ◽  
Reduced Order Observer ◽  
Multi Agent ◽  
The Stability ◽  
Output Information ◽  
Theoretical Results

This paper considers a consensus control of a general linear multi-agent system with time-varying communication delays. Since each agent can only use the relative output information from its neighbors, a reduced-order observer-based control protocol is proposed to guarantee consensus on the directed communication network. The stability of the closed-loop system is analyzed for the cases with uniform delays and nonuniform time-varying delays, respectively. Moreover, the upper bounds of the communication delays are obtained respectively for the two cases. Finally, two numerical examples are provided to illustrate the proposed theoretical results.

SYNCHRONIZATION OF UNCERTAIN CHAOTIC SYSTEMS BASED ON THE FUZZY-MODEL-BASED APPROACH

2006 ◽  
Vol 16 (05) ◽  
pp. 1435-1444 ◽  
Author(s):  
H. K. LAM ◽  
F. H. F. LEUNG
Keyword(s):  
Chaotic Systems ◽  
Fuzzy Model ◽  
Parameter Design ◽  
Parameter Uncertainties ◽  
Model Based ◽  
Synchronization Problem ◽  
Programming Techniques ◽  
Uncertain Chaotic Systems ◽  
Switching Controller ◽  
The Stability

This paper investigates the synchronization of chaotic systems subject to parameter uncertainties. Based on the fuzzy-model-based approach, a switching controller will be proposed to deal with the synchronization problem. The stability conditions will be derived based on the Lyapunov approach. The tracking performance and parameter design of the proposed switching controller will be formulated as a generalized eigenvalue minimization problem which can be solved numerically using some convex programming techniques. Simulation examples will be given to show the effectiveness of the proposed approach.

Modeling of Stochastic Von Neumann Model of Mobile Service

2011 ◽  
Vol 474-476 ◽  
pp. 11-14
Author(s):  
Fang Qin Xu ◽  
Lei Jiang
Keyword(s):  
Singular Systems ◽  
Mobile Services ◽  
Mobile Service ◽  
Output Process ◽  
Input Output ◽  
Parameter Uncertainties ◽  
Von Neumann ◽  
General Systems ◽  
The Stability ◽  
Neumann Model

A stochastic Von Neumann model to describe companies’ input-output process on mobile services is provided. Through the theories from input-output economics, an extended singular stochastic Von Neumann model on mobile service is researched. The problem of stability of this kind of stochastic Von Neumann model on mobile services is researched. A new mathematic method is applied to study the singular systems without converting them into general systems. The parameter uncertainties are considered. A new stability criterion for the extended stochastic Von Neumann model is given to ensure the stability of input-output model.

Fuzzy Control for Nonlinear Uncertain T-S Fuzzy Systems with Time-Varying Delays

2013 ◽  
Vol 341-342 ◽  
pp. 668-673
Author(s):  
Yi Min Li ◽  
Yuan Yuan Li
Keyword(s):  
Stability Analysis ◽  
Discrete Time ◽  
Fuzzy Model ◽  
Optimization Techniques ◽  
Linear Matrix ◽  
Time Varying ◽  
Parameter Uncertainties ◽  
Lmi Optimization ◽  
System A ◽  
The Stability

This paper studies the stability analysis of discrete time-varying system with parameter uncertainties and disturbances. The system under consideration is subject to time-varying non-bounded parameter uncertainties in both the state and measured output matrices. To facilitate the stability analysis, the T-S fuzzy model is employed to represent the discrete-time nonlinear system. A fuzzy observer is used to guarantee the Lyapunov stability of the closed-loop system and reduces the effect of the disturbance input on the controlled output to a prescribed level for all admissible uncertainties. The control and observer matrices can be obtained by directly solving a set of linear matrix inequality (LMI) via the existing LMI optimization techniques. Finally, an example is provided to demonstrate the effectiveness of the proposed approach.

scholarly journals Stability Analysis of Rotor-Bearing Systems under the Influence of Misalignment and Parameter Uncertainty

2021 ◽  
Vol 11 (17) ◽  
pp. 7918
Author(s):  
Xiaodong Sun ◽  
Kian K. Sepahvand ◽  
Steffen Marburg
Keyword(s):  
Computation Time ◽  
Parametric Uncertainty ◽  
Parameter Uncertainties ◽  
Misalignment Effect ◽  
Stability Threshold ◽  
Rotating Systems ◽  
Rotor Bearing ◽  
Run Up ◽  
The Stability ◽  
The Impact

Stability is a well-known challenge for rotating systems supported by hydrodynamic bearings (HDBs), particularly for the condition where the misalignment effect and the parametric uncertainty are considered. This study investigates the impact of misalignment and inherent uncertainties in bearings on the stability of a rotor-bearing system. The misalignment effect is approximately described by introducing two misaligned angles. The characteristics of an HDB, such as pressure distribution and dynamic coefficients, are calculated by the finite difference method (FDM). The stability threshold is evaluated as the intersection of run-up curve and borderline. Viscosity and clearance are considered as uncertain parameters. The generalized polynomial chaos (gPC) expansion is adopted to quantify the uncertainty in parameters by evaluating unknown coefficients. The unknown gPC coefficients are obtained by using the collocation method. The results obtained by the gPC expansion are compared with those of the Monte Carlo (MC) simulation. The results show that the characteristics of the HDB and the stability threshold are affected by misalignment and parameter uncertainties. As the uncertainty analysis using the gPC expansion is performed on a relatively small number of predefined collocation points compared with the large number of MC samples, the method is very efficient in terms of computation time.

scholarly journals Robust dynamic inversion control of flight control system based on L1 adaptive structure

2021 ◽  
Vol 39 (5) ◽  
pp. 995-1004
Author(s):  
Yu LI ◽  
Xiaoxiong LIU ◽  
Ruichen MING ◽  
Shaoshan SUN ◽  
Weiguo ZHANG
Keyword(s):  
Control System ◽  
Flight Control ◽  
Dynamic Performance ◽  
Dynamic Inversion ◽  
Control Law ◽  
Flight Control System ◽  
Parameter Uncertainties ◽  
Strong Robustness ◽  
Adaptive Structure ◽  
The Stability

Nonlinear Dynamic Inversion(NDI) control has excellent rapidity and decoupling ability, unfortunately it lacks the essential robustness to disturbance. From the perspective of enhancing the robustness, an adaptive NDI method based on L1 adaptive structure is proposed. The L1 adaptive structure is introduced into the NDI control to enhance its robustness, which also guarantees the stability and expected dynamic performance of the system suffering from the disturbance influence. Secondly, the flight control law of the advanced aircraft is designed based on the present method to improve the robustness and fault tolerance of the flight control system. Finally, the effectiveness of the flight control law based on the present approach is verified under the fault disturbance. The results showed that the flight control law based on L1 adaptive NDI has excellent dynamic performance and strong robustness to parameter uncertainties and disturbances.

Adaptive Compensation of Sensor Runout for Magnetic Bearings With Uncertain Parameters: Theory and Experiments

1999 ◽  
Vol 123 (2) ◽  
pp. 211-218 ◽  
Author(s):  
Joga D. Setiawan ◽  
Ranjan Mukherjee ◽  
Eric H. Maslen
Keyword(s):  
Magnetic Bearing ◽  
Magnetic Bearings ◽  
Parameter Uncertainties ◽  
Persistent Excitation ◽  
Electrical And Magnetic Properties ◽  
Periodic Disturbances ◽  
Mass Unbalance ◽  
On Line ◽  
The Stability ◽  
Rotor Balancing

The problem of sensor runout in magnetic bearing systems has been largely overlooked due to similarities with mass unbalance in creating periodic disturbances. While the effect of mass unbalance can be significantly reduced, if not eliminated, through rotor balancing, sensor runout disturbance is unavoidable since it originates from physical nonconcentricity between rotor and stator. Sensor runout is also caused by nonuniform electrical and magnetic properties around the sensing surface. To improve performance of magnetic bearings, we present an adaptive algorithm for sensor runout compensation. It guarantees asymptotic stability of the rotor geometric center and on-line feedforward cancellation of runout disturbances using persistent excitation. Some of the advantages of our algorithm include simplicity of design and implementation, stability, and robustness to plant parameter uncertainties. The stability and robustness properties are derived from passivity of the closed-loop system. Numerical simulations are presented to demonstrate efficacy of the algorithm and experimental results confirm stability and robustness for large variation in plant parameters.

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