Adaptive Second-Order Sliding Mode Algorithm-Based Modified Function Projective Synchronization of Uncertain Hyperchaotic Systems

This article proposes a synchronization technique for uncertain hyperchaotic systems in the modified function projective manner using integral fast terminal sliding mode (I-FTSM) and adaptive second-order sliding mode algorithm. The new I-FTSM manifolds are introduced with the aim of having the fast convergence speed. The proposed continuous controller not only results in the robustness and high-accuracy synchronization in the presence of unknown external disturbances and/or model uncertainties but also helps alleviating the chattering effect significantly. Numerical simulation results are provided to illustrate the effectiveness of the proposed control design technique and verify the theoretical analysis

A new continuous high order sliding mode controller for synchronizing perturbed Genesio-Tesi systems in finite time

This paper presents the solution for synchronizing of perturbed Genesio-Tesi systems in finite time. A new homogeneous high order sliding mode control approach is introduced ensuring the finite-time synchronization despite perturbations in the considered systems. By combining a proposed Lyapunov function and the homogeneity concept, the proposed controller possesses superior features such as requiring only one control input signal to obtain finite-time synchronization, resulting in a continuous control signal that significantly reduces the chattering effect without an additional differentiator, and compensating a wide class of perturbations. The computer simulation results are provided to demonstrate the effectiveness of the proposed control approach, compared with two existing control schemes. (C) 2020 The Franklin Institute. Published by Elsevier Ltd. All rights reserved

A modified generic second order algorithm with fixed-time stability

This paper introduces a modified second order sliding mode algorithm with fixed-time stability analysis based on the Lyapunov function approach. An existing second order sliding mode algorithm is generalized, which provides superior features on convergence rate, accuracy, and robustness against a class of perturbations. The performance of the proposed algorithm is compared with existing algorithms through designing observers first. Then, the proposed algorithm-based controller which displays the fixed-time convergence property is designed to validate its effectiveness and to confirm the theoretical analysis. (C) 2020 ISA. Published by Elsevier Ltd. All rights reserved

Synchronization of perturbed Genesio-Tesi chaotic systems via a new finite-time control

This paper investigates the synchronization problem for perturbed Genesio-Tesi chaotic system. Based on Lyapnov stability theory, a new finite-time control method is proposed to ensure that the synchronization takes place in finite time. Numerical simulation results are provided to show the effectiveness of the proposed metho

Prescribed performance adaptive finite-time control for uncertain horizontal platform systems

This paper presents a new approach to the design of prescribed performance adaptive control for uncertain horizontal platform systems with the finite-time convergence. Following an appropriate performance function and error transformation, a new adaptive control law is proposed by using a novel integral non-singular terminal sliding mode surface. The proposed approach simultaneously guarantees that (i) the transient responses of the closed-loop system possess some advanced properties such as the existence of the prespecified lower bound of the convergence rate and of the pre-established upper bound of the maximum overshoot; and (ii) the finite-time convergence of the state trajectories/tracking errors to zero. The global stability and finite-time convergence are strictly analyzed. The proposed method is clarified and verified through two numerical simulation examples. (C) 2020 ISA. Published by Elsevier Ltd. All rights reserved

Comments on "Continuous Integral Terminal Third-Order Sliding Mode Motion Control for Piezoelectric Nanopositioning System"

In paper [1], there are some errors directly related to the major results drawn. This note is thus aimed at providing a correct version of the paper [1

Fixed-Time Complex Modified Function Projective Lag Synchronization of Chaotic (Hyperchaotic) Complex Systems

A novel fixed-time controller is proposed to perform fixed-time complex modified function projective lag synchronization of chaotic (hyperchaotic) complex systems. The synchronization is obtained after a finite time that could be preestablished without the knowledge of the initial states of both synchronized chaotic (hyperchaotic) complex systems. The global fixed-time stability of the closed-loop systems is rigorously proven based on Lyapunov analysis. Some simulation examples are provided to demonstrate the effectiveness and feasibility of the proposed method and verify the theoretical results

A Novel High-Speed Third-Order Sliding Mode Observer for Fault-Tolerant Control Problem of Robot Manipulators

In this paper, a novel fault-tolerant control tactic for robot manipulator systems using only position measurements is proposed. The proposed algorithm is constructed based on a combination of a nonsingular fast terminal sliding mode control (NFTSMC) and a novel high-speed third-order sliding mode observer (TOSMO). In the first step, the high-speed TOSMO is proposed for the first time to approximate both the system velocity and the lumped unknown input with a faster convergence time compared to the TOSMO. The faster convergence speed is obtained thanks to the linear characteristic of the added elements. In the second step, the NFTSMC is designed based on a nonsingular fast terminal sliding (NFTS) surface and the information obtained from the proposed high-speed TOSMO. Thanks to the combination, the proposed controller–observer tactic provides excellent features, such as a fast convergence time, high tracking precision, chattering phenomenon reduction, robustness against the effects of the lumped unknown input and velocity requirement elimination. Especially, the proposed observer does not only improve the convergence speed of the estimated signals, but also increases the system dynamic response. The system’s finite-time stability is proved using the Lyapunov theory. Finally, to validate the efficiency of the proposed strategy, simulations on a PUMA560 robot manipulator are performed

Autonomous UAV Trail Navigation with Obstacle Avoidance Using Deep Neural Networks

This paper proposes a vision-based bike trail following approach with obstacle avoidance using CNN (Convolutional Neural Network) for the UAV (Unmanned Aerial Vehicle). The UAV is controlled to follow a given trail while keeping its position near the center of the trail using the CNN. Also, to return to the original path when the UAV goes out of the path or the camera misses the trail due to disturbances such as wind, the control commands from the CNN are stored for a certain duration of time and used for recovering from such disturbances. To avoid obstacles during the trail navigation, the optical flow computed with another CNN is used to determine the safe maneuver. By combining these methods of i) trail following, ii) disturbance recovery, and iii) obstacle avoidance, the UAV deals with various situations encountered when traveling on the trail. The feasibility and performance of the proposed approach are verified through realistic simulations and flight experiments in real-world environments