Wyniki wyszukiwania - BazTech

1

Adaptive self-regulation PID control of course-keeping for ships

Zhang Qiang, Ding Zhongyu, Zhang Meijuan

Polish Maritime Research

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2020

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nr 1

39--45

EN

To solve the nonlinear control problems of the unknown time-varying environmental disturbances and parametric uncertainties for ship course-keeping control, this paper presents an adaptive self-regulation PID (APID) scheme which can ensure the boundedness of all signals in the ship course-keeping control system by using the Lyapunov direct method. Compared with the traditional PID control scheme, the APID control scheme not only is independent of the model parameters and the unknown input, but also can regulate the gain of PID adaptively and resist time-varying disturbances well. Simulation results illustrate the effectiveness and the robustness of the proposed control scheme.

2

Balance and stability issues in lower extremity exoskeletons: A systematic review

Hamza Mukhtar Fatihu, Ghazilla Raja Ariffin Raja, Muhammad Bashir Bala, Yap Hwa Jen

Biocybernetics and Biomedical Engineering

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2020

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Vol. 40, no. 4

1666--1679

EN

The lower extremity exoskeletons (LEE) are used as an assistive device for disabled people, rehabilitation for paraplegic, and power augmentation for military or industrial workers. In all the applications of LEE, the dynamic and static balance, prevention of falling, ensuring controller stability and smooth human-exoskeleton interaction are of critical importance for the safety of LEE users. Although numerous studies have been conducted on the balance and stability issues in LEEs, there is yet to be a systematic review that provides a holistic viewpoint and highlights the current research challenges. This paper reviews the advances in the inclusion of falling recognition, balance recovery and stability assurance strategies in the design and application of LEEs. The current status of research on LEEs is presented. It has been found that Zero Moment Point (ZMP), Centre of Mass (CoM) and Extrapolated Center of mass (XCoM) ideas are mostly used for balancing and prevention of falling. In addition, Lyapunov stability criteria are the dominant methods for controller stability confirmation and smooth human-exoskeleton interaction. The challenges and future trend of this domain of research are discussed. Researchers can use this review as a basis to further develop methods for ensuring the safety of LEE's users.

3

Synchronization of neuronal bursting using backstepping control with recursive feedback

Rasappan Suresh

Archives of Control Sciences

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2019

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Vol. 29, No. 4

617--642

EN

J. L. Hindmarsh, R. M. Rose introduced the concept of neuronal burst. In this paper, synchronization is investigated for the construction of a model of neuronal burst using backstepping control with recursive feedback. Synchronization for a model of neuronal bursting system is established using Lyapunov stability theory. The backstepping scheme is a recursive procedure that links the choice of a Lyapunov function with the design of a controller. The backstepping control method is effective and convenient to synchronize identical systems. Numerical simulations are furnished to illustrate and validate the synchronization result derived in this paper.

4

Stability of softly switched multiregional dynamic output controllers with a static antiwindup filter: a discrete-time case

Zubowicz T., Brdyś M. A.

International Journal of Applied Mathematics and Computer Science

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2013

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Vol. 23, no. 1

65--73

EN

This paper addresses the problem of model-based global stability analysis of discrete-time Takagi–Sugeno multiregional dynamic output controllers with static antiwindup filters. The presented analyses are reduced to the problem of a feasibility study of the Linear Matrix Inequalities (LMIs), derived based on Lyapunov stability theory. Two sets of LMIs are considered candidate derived from the classical common quadratic Lyapunov function, which may in some cases be too conservative, and a fuzzy Lyapunov function candidate, which has been proven to significantly reduce the conservatism level, although at the cost of increasing the number of LMIs. Two numerical examples illustrate the main result.

5

Positive discrete-time linear Lyapunov systems

Kaczorek T.

Journal of Automation Mobile Robotics and Intelligent Systems

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2008

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Vol. 2, No. 3

13-19

EN

The notion of positive discrete-time Lyapunov system is introduced. Solution of the Lyapunov state equation is derived and necessary and sufficient conditions for the positivity of Lyapunov system are established. Different necessary and sufficient conditions for the asymptotic stability of the positive Lyapunov systems are given. Using the Kronecker product of matrices necessary and sufficient conditions for reachability and controllability of the positive Lyapunov systems are established. The considerations are illustrated by numerical example.

6

Vibrations Induced During a Stability Loss of Periodic Trajectories of the Manipulator

Szumiński P., Kapitaniak T.

Machine Dynamics Problems

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2004

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Vol. 28, No. 2

65-85

EN

We present how to avoid dangerous situations that occur during a robot periodic motion and are caused by different kinds of vibrations. Theoretical analysis of stability regions of nonlinear and linearized system and of the ways of inducing vibrations during a stability loss of periodic trajectories is developed. For practical control of motion a common part of areas of stability received for nonlinear and using linearized Poincare map can be taking into considerations. The areas of stability are identificated by the bifurcation diagrams and Poincare maps. Stability regions of periodic trajectories as a function of varying parameters of the system are investigated . As a practical tool for the control of stability, a spectrum of Lyapunov exponents is proposed. To illustrate our method theoretically and numerically, a model of the RRP-type manipulator has been considered.