scholarly journals Adaptive Control for Multi-Shaft with Web Materials Linkage Systems

Inventions ◽  
2021 ◽  
Vol 6 (4) ◽  
pp. 76
Author(s):  
Van Trong Dang ◽  
Duc Thinh Le ◽  
Van-Anh Nguyen-Thi ◽  
Danh Huy Nguyen ◽  
Thi Ly Tong ◽  
...  
Keyword(s):  
Disturbance Observer ◽  
Tracking Error ◽  
Variable Structure ◽  
High Gain ◽  
Adaptive Performance ◽  
Performance Benchmarks ◽  
And Performance ◽  
The Moment ◽  
Fuzzy Disturbance Observer ◽  
Estimate System

In this paper, a fuzzy disturbance observer and a high-gain disturbance observer based on a variable structure controller are applied to deal with imprecise multi-shaft with web materials linkage systems taking into account the variation of the moment of inertia. Specifically, a high-gain disturbance observer and an adaptive fuzzy algorithm are separately applied to estimate system uncertainties and external disturbances. The high-gain disturbance observer is designed with auxiliary variables to avoid the amplification of the measurement disturbance, and the fuzzy disturbance observer has the advantage that it does not depend on model information. The convergence properties of the tracking error are analytically proven using Lyapunov’s theory. The obtained numerical results demonstrate the validity and the adaptive performance of the proposed control law in case the system is exposed to uncertainties and disturbances. Important remarks on the design process and performance benchmarks of the two observers are also demonstrated.

A fault-tolerant control scheme within adaptive disturbance observer for hypersonic vehicle

2017 ◽  
Vol 233 (3) ◽  
pp. 1071-1088 ◽  
Author(s):  
Jun Zhou ◽  
Jing Chang ◽  
Zongyi Guo
Keyword(s):  
Disturbance Observer ◽  
Fault Tolerant ◽  
Sliding Mode ◽  
Fault Tolerant Control ◽  
Lyapunov Theory ◽  
Sliding Mode Controller ◽  
Performance Guarantees ◽  
Uncertain Model ◽  
Control Scheme ◽  
And Performance

The paper describes the design of a fault-tolerant control scheme for an uncertain model of a hypersonic reentry vehicle subject to actuator faults. In order to improve superior transient performances for state tracking, the proposed method relies on a back-stepping sliding mode controller combined with an adaptive disturbance observer and a reference vector generator. This structure allows for a faster response and reduces the overshoots compared to linear conventional disturbance observers based sliding mode controller. Robust stability and performance guarantees of the overall closed-loop system are obtained using Lyapunov theory. Finally, numerical simulations results illustrate the effectiveness of the proposed technique.

scholarly journals Autistic Traits Predict Social-Contact Uncertainty in University Students

2021 ◽  
Vol 12 ◽  
Author(s):  
Alex Bertrams ◽  
Myriam Zäch
Keyword(s):  
Social Anxiety ◽  
University Students ◽  
Social Contact ◽  
Autistic Traits ◽  
Well Being ◽  
Cross Sectional ◽  
Socially Anxious ◽  
And Performance ◽  
The Moment ◽  
The University

Social anxiety (alternatively: social-contact uncertainty) in the university context can lead to reduced health, well-being, and performance, and can even cause premature leaving of education. With the present study, we intended to supplement cross-sectional studies on students' autistic traits and social anxiety with longitudinal findings. We measured autistic traits and social-contact uncertainty of 118 university students on two occasions, roughly 1 year apart. Correlation, multiple regression, and cross-lagged analyses showed that more pronounced autistic traits predicted higher future social-contact uncertainty. Social-contact uncertainty did not predict autistic traits. We conclude that university students who are high in autistic traits tend not only to be more socially anxious at the moment but have a heightened risk of still being so in the future.

Sliding Mode Control of a Three Degrees of Freedom Anthropoid Robot by Driving the Controller Parameters to an Equivalent Regime

2000 ◽  
Vol 122 (4) ◽  
pp. 632-640 ◽  
Author(s):  
M. Onder Efe ◽  
Okyay Kaynak ◽  
Xinghuo Yu
Keyword(s):  
Degrees Of Freedom ◽  
Sliding Mode ◽  
Initial Conditions ◽  
Tracking Error ◽  
Variable Structure ◽  
Mathematical Representation ◽  
Dynamic Complexity ◽  
Variable Structure Systems ◽  
Sliding Motion ◽  
Three Degrees Of Freedom

Noise rejection, handling the difficulties coming from the mathematical representation of the system under investigation and alleviation of structural or unstructural uncertainties constitute prime challenges that are frequently encountered in the practice of systems and control engineering. Designing a controller has primarily the aim of achieving the tracking precision as well as a degree of robustness against the difficulties stated. From this point of view, variable structure systems theory offer well formulated solutions to such ill-posed problems containing uncertainty and imprecision. In this paper, a simple controller structure is discussed. The architecture is known as Adaptive Linear Element (ADALINE) in the framework of neural computing. The parameters of the controller evolve dynamically in time such that a sliding motion is obtained. The inner sliding motion concerns the establishment of a sliding mode in controller parameters, which aims to minimize the error on the controller outputs. The outer sliding motion is designed for the plant. The algorithm discussed drives the error on the output of the controller toward zero learning error level, and the state tracking error vector of the plant is driven toward the origin of the phase space simultaneously. The paper gives the analysis of the equivalence between the two sliding motions and demonstrates the performance of the algorithm on a three degrees of freedom, anthropoid robotic manipulator. In order to clarify the performance of the scheme, together with the dynamic complexity of the plant, the adverse effects of observation noise and nonzero initial conditions are studied. [S0022-0434(00)01704-4]

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