Time-varying lag smoothing with intermittent unknown inputs: A defense strategy against deception attacks

2014 ◽  
Author(s):  
J. Y. Keller ◽  
D. Sauter
Keyword(s):  
Time Varying ◽  
Defense Strategy ◽  
Unknown Inputs

A robust fault detection design for uncertain Takagi–Sugeno models with unknown inputs and time-varying delays

2014 ◽  
Vol 11 ◽  
pp. 98-117 ◽  
Author(s):  
Saeed Ahmadizadeh ◽  
Jafar Zarei ◽  
Hamid Reza Karimi
Keyword(s):  
Fault Detection ◽  
Time Varying ◽  
Unknown Inputs ◽  
Robust Fault Detection ◽  
Takagi Sugeno

Time-Varying Group Formation-Containment Tracking Control for General Linear Multiagent Systems With Unknown Inputs

2021 ◽  
pp. 1-13
Author(s):  
Yizhou Lu ◽  
Xiwang Dong ◽  
Qingdong Li ◽  
Jinhu Lu ◽  
Zhang Ren
Keyword(s):  
Multiagent Systems ◽  
Tracking Control ◽  
Group Formation ◽  
General Linear ◽  
Time Varying ◽  
Unknown Inputs

scholarly journals Non-asymptotic state estimation for a class of linear time-varying systems with unknown inputs

2014 ◽  
Vol 47 (3) ◽  
pp. 3732-3738 ◽  
Author(s):  
D.Y. Liu ◽  
T.M. Laleg-Kirati ◽  
W. Perruquetti ◽  
O. Gibaru
Keyword(s):  
State Estimation ◽  
Linear Time ◽  
Asymptotic State ◽  
Time Varying ◽  
Unknown Inputs ◽  
Time Varying Systems

Integration of identification and vibration control of time-varying structures subject to unknown seismic ground excitation

2020 ◽  
Vol 26 (15-16) ◽  
pp. 1330-1344 ◽  
Author(s):  
Ying Lei ◽  
Jubin Lu ◽  
Jinshan Huang
Keyword(s):  
Vibration Control ◽  
Real Time ◽  
Dynamic Responses ◽  
Structural Vibration ◽  
Earthquake Ground Motion ◽  
Time Varying ◽  
Earthquake Excitation ◽  
Structural Dynamic ◽  
Invariant Structure ◽  
Unknown Inputs

The synthesis of structural health monitoring and vibration control is important in order to provide facilities for constructing smart structures. In recent years, some techniques have been developed to integrate structural identification and optimal vibration control. However, it is still challenging to integrate the identification and vibration control of time-varying structures subject to unknown earthquake excitation. The main difficulties are that structural dynamic responses collected by a simple harmonic motion system are absolute responses under unknown earthquake ground motion while previous identification approaches for unknown external excitation are not applicable for this situation and the need of an efficient algorithm to accurately track the various scenarios of time-varying structures with inexpensive computation to ensure the real-time performance requested by structural vibration control. In this paper, a novel algorithm is presented, in which structural time-varying parameters are treated as ‘virtual unknown inputs’ to the underlying time-invariant structure, a generalized Kalman filter with unknown inputs is proposed for joint identification of joint structural state, unknown earthquake excitation and ‘virtual unknown inputs’ with only partially measured structural absolute responses, and the identification results are integrated in real-time with the instantaneous optimal control scheme to reach the goal of optimal semi-active control provided by magneto-rheological dampers. Some numerical examples of integrated identification and vibration control of various time-varying structures subject to unknown earthquake excitation are used to demonstrate the performances of the proposed algorithm.

Finite-Time State-Observer for a Class of Linear Time-Varying Systems with Unknown Inputs

2021 ◽  
pp. 1-1
Author(s):  
Jorge Davila ◽  
Markus Tranninger ◽  
Leonid Fridman
Keyword(s):  
Finite Time ◽  
Linear Time ◽  
State Observer ◽  
Time Varying ◽  
Unknown Inputs ◽  
Time Varying Systems

scholarly journals Online Identification of Time-Variant Structural Parameters Under Unknown Inputs Basing On Extended Kalman Filter

2021 ◽  
Author(s):  
Xiaoxiong Zhang ◽  
Jia He ◽  
Xugang Hua ◽  
Zhengqing Chen ◽  
Ou Yang
Keyword(s):  
Kalman Filter ◽  
Extended Kalman Filter ◽  
Structural Parameters ◽  
Optimization Procedure ◽  
Unbiased Estimation ◽  
Time Varying ◽  
Time Step ◽  
Varying Parameters ◽  
Unknown Inputs ◽  
Time Varying Parameters

Abstract To date, a number of parameter identification methods have been developed for the purpose of structural health monitoring and vibration control. Among them, the extended Kalman filter (EKF) series methods are attractive in view of the efficient unbiased estimation in recursive manner. However, most of these methods are performed on the premise that the parameters are time-invariant and/or the loadings are known. To circumvent the aforementioned limitations, an online EKF with unknown input (OEKF-UI) approach is proposed in this paper for the identification of time-varying parameters and the unknown excitation. A revised observation equation is obtained with the aid of projection matrix. To capture the changes of structural parameters in real-time, an online tracking matrix (OTM) associated with the time-varying parameters is introduced and determined via an optimization procedure. Then, based on the principle of EKF, the recursive solution of structural states including the time-variant parameters can be analytically derived. Finally, using the estimated structural states, the unknown inputs are identified by means of least-squares estimation (LSE) at the same time-step. The effectiveness of the proposed approach is validated via linear and nonlinear numerical examples with the consideration of parameters being varied abruptly.

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