Robust control for uncertain nonlinear feedback system using operator-based right coprime factorization

2019 ◽  
Vol 6 (3) ◽  
pp. 824-829
Author(s):  
Ni Bu ◽  
Wei Chen ◽  
Longguo Jin ◽  
Yandong Zhao
Keyword(s):  
Robust Control ◽  
Feedback System ◽  
Nonlinear Feedback ◽  
Coprime Factorization

scholarly journals A Flexible Nonlinear Feedback System That Captures Diverse Patterns of Adaptation and Rebound

2008 ◽  
Vol 10 (1) ◽  
pp. 70-83 ◽  
Author(s):  
Johan Gabrielsson ◽  
Lambertus A. Peletier
Keyword(s):  
Feedback System ◽  
Nonlinear Feedback

An IPEM for optimal control of uncertain beam-moving mass systems with saturation nonlinearity

2017 ◽  
Vol 24 (13) ◽  
pp. 2760-2781
Author(s):  
Xiao-Xiao Liu ◽  
Xing-Min Ren
Keyword(s):  
Nonlinear Control ◽  
Vibration Suppression ◽  
Estimation Method ◽  
Feedback System ◽  
Random Excitation ◽  
Point Estimation ◽  
Maximum Principles ◽  
Moving Mass ◽  
Nonlinear Feedback ◽  
Point Estimation Method

This paper addresses the vibration control of single-span beams subjected to a moving mass by coupling the saturated nonlinear control and an improved point estimation method (IPEM). An optimal nonlinear feedback control law, for a kind of uncertain linear system with actuator nonlinearities, is derived using the combination of Pontryagin's maximum principles and the improved point estimation method. The stability of the feedback system is guaranteed using a Lyapunov function. In order to obtain the instantaneously probabilistic information of output responses, a novel moment approach is presented by combining the improved point estimation method, the maximum entropy methodology and the probability density evolution theory. In addition to the consideration of stochastic system parameters, the external loadings are considered as a nonstationary random excitation and a moving sprung mass, respectively. The proposed strategy is then used to perform vibration suppression analysis and parametric sensitivity analysis of the given beam. From numerical simulation results, it is deduced that the improved point estimation method is a priority approach to the optimal saturated nonlinear control of stochastic beam systems. This observation has widespread applications and prospects in vehicle–bridge interaction and missile–gun systems.

scholarly journals Multitechnique Concise Robust Control for the Insulation Containment Space Pressure Control of LNG Carrier

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Zuojing Su ◽  
Xianku Zhang ◽  
Xu Han
Keyword(s):  
Time Delay ◽  
Robust Control ◽  
Energy Saving ◽  
Pressure Control ◽  
Smith Predictor ◽  
Mapping Technique ◽  
Delay Model ◽  
Nonlinear Feedback ◽  
Maintenance System ◽  
Control Scheme

In this note, a novel multitechnique concise robust control scheme, based on the mirror mapping technique (MMT), closed-loop gain shaping algorithm (CGSA), Smith predictor (SP), and nonlinear feedback technique (NFT), is proposed for the pressure control of the liquefied natural gas (LNG) carrier insulation containment space. Firstly, a kind of integral unstable time-delay model is obtained by linearizing the nonlinear model of the pressure maintenance system around its equilibrium. By using the MMT and CGSA, one acquires the corresponding stable mirror mapping model of the unstable linear model and the designed controller. And the SP is introduced to tackle the time-delay problem. In addition, for the purpose of energy saving, the NFT is added into the control scheme. Finally, a set of experiments has been employed to illustrate the control effects, and the results show that it can achieve satisfying performance in aspects of disturbance rejection and energy saving.

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