scholarly journals Globally stable fast tracking control of a chain of integrators with input saturation and disturbances: A holistic approach

2011 ◽  
Author(s):  
Lu Lu ◽  
Bin Yao
Keyword(s):  
Tracking Control ◽  
Input Saturation ◽  
Holistic Approach ◽  
Fast Tracking ◽  
A Chain ◽  
Globally Stable

scholarly journals Iterative Learning Tracking Control of Nonlinear Multiagent Systems with Input Saturation

Complexity ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Bingyou Liu ◽  
Zhengzheng Zhang ◽  
Lichao Wang ◽  
Xing Li ◽  
Xiongfeng Deng
Keyword(s):  
Tracking Control ◽  
Control Algorithm ◽  
Multiagent System ◽  
Input Saturation ◽  
Iterative Learning ◽  
Adaptive Iterative Learning Control ◽  
External Interference ◽  
Adaptive Time ◽  
Precision Tracking ◽  
Precision Tracking Control

A tracking control algorithm of nonlinear multiple agents with undirected communication is studied for each multiagent system affected by external interference and input saturation. A control design scheme combining iterative learning and adaptive control is proposed to perform parameter adaptive time-varying adjustment and prove the effectiveness of the control protocol by designing Lyapunov functions. Simulation results show that the high-precision tracking control problem of the nonlinear multiagent system based on adaptive iterative learning control can be well realized even when the input is saturated. Finally, the validity of the proposed algorithm is verified by numerical analysis.

scholarly journals Crisis of meaning in connection with mental distress of a modern man

2021 ◽  
Vol 54 (3-4) ◽  
pp. 154-170
Author(s):  
Sebastjan Kristovič
Keyword(s):  
Mental Distress ◽  
Holistic Approach ◽  
Psychometric Instrument ◽  
Spiritual Dimension ◽  
Existential Crisis ◽  
Doctor Of Philosophy ◽  
The Will ◽  
Crisis Of Meaning ◽  
A Chain ◽  
Precise Moment

In contrast with the contemporary spirit, which directs a person towards their own needs, satisfactions, and desires, logotherapy views the person and its life as an assignment. Man is not an individual "for himself" (according to Freud, the main internal motivational force is "the will of pleasure" and "the will of power" according to Adler), but a being of sense or a being for someone or something. According to Frankl, the purpose is defined as tasks, which life sets us in a precise moment and in a precise situation. These are tasks requiring a responsible reaction and a specific realisation of values. Each of them is unique. Each individual is responsible for a task, and only he can respond to it in a responsible man-ner. In this sense, life can be seen as a chain, whose links are the tasks themselves. Each in-dividual is unique, with a unique goal in life, which consists of individual, equally unique tasks. The centre of logotherapy is future - tasks and meanings. The founder of logotherapy is Viktor E. Frankl, who was a doctor of medicine and doctor of philosophy, and a professor of neurology and psychiatry at the University of Vienna. The third psychotherapeutic school in Vienna - logotherapy - is based on a holistic approach to an individual, which means that it analyses a person on a physical, mental, and spiritual level. Spiritual dimension is, among others, a place of realisation of responsibility and freedom or space of realisation of actual possibilities and tasks. Existential crisis, exis-tential vacuum, and noogenic neuroses are issues and mental problems, which originate from the spiritual dimension. This means failing to perceive and failing in life as an assignment. The empirical part of the research, which is based on the psychometric instrument LOGO-test, performed on two hundred re-spondents, gave us the results that even 24 percent of respondents are in various mental distresses and seriously existentially endangered. The paper highlights the most problematic areas and causes for such mental distress. The COVID-19 pandemic only deepened and revealed this crisis of meaning.

Adaptive NN finite-time tracking control of output constrained nonlinear system with input saturation

2018 ◽  
Vol 92 (4) ◽  
pp. 1845-1856 ◽  
Author(s):  
Shiyi Zhao ◽  
Hongjing Liang ◽  
Peihao Du ◽  
Suwen Qi
Keyword(s):  
Nonlinear System ◽  
Finite Time ◽  
Tracking Control ◽  
Input Saturation

scholarly journals Robust tracking control for two classes of variable stiffness actuators based on linear extended state observer with estimation error compensation

2020 ◽  
Vol 17 (2) ◽  
pp. 172988142091177
Author(s):  
Jishu Guo ◽  
Junmei Guo ◽  
Zhongjun Xiao
Keyword(s):  
Linear System ◽  
Tracking Control ◽  
Estimation Error ◽  
Input Saturation ◽  
Variable Stiffness ◽  
State Observer ◽  
Extended State Observer ◽  
Extended State ◽  
Linear Extended State Observer ◽  
Variable Stiffness Actuators

In this article, a novel robust tracking control scheme based on linear extended state observer with estimation error compensation is proposed for the tracking control of the antagonistic variable stiffness actuator based on equivalent nonlinear torsion spring and the serial variable stiffness actuator based on lever mechanism. For the dynamic models of these two classes of variable stiffness actuators, considering the parametric uncertainties, the unknown friction torques acting on the driving units, the unknown external disturbances acting on the output links and the input saturation constraints, an integral chain pseudo-linear system with input saturation constraints and matched lumped disturbances is established by coordinate transformation. Subsequently, the matched lumped disturbances in the pseudo-linear system are extended to the new system states, and we obtain an extended integral chain pseudo-linear system. Then, we design the linear extended state observer to estimate the unknown states of the extended pseudo-linear system. Considering the input saturation constraints in the extended pseudo-linear system and the estimation errors of the linear extended state observer with fixed preset observation gains, the adaptive input saturation compensation laws and the novel estimation error compensators are designed. Finally, a robust tracking controller based on linear extended state observer, sliding mode control, adaptive input saturation compensation laws, and estimating error compensators is designed to achieve simultaneous position and stiffness tracking control of these two classes of variable stiffness actuators. Under the action of the designed controller, the semi-global uniformly ultimately bounded stability of the closed-loop system is proved by the stability analysis of the candidate Lyapunov function. The simulation results show the effectiveness, robustness, and adaptability of the designed controller in the tracking control of these two classes of variable stiffness actuators. Furthermore, the simulation comparisons show the effectiveness of the proposed estimation error compensation measures in reducing the tracking errors and improving the disturbance rejection performance of the controller.

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