A novel nonsingular integral terminal sliding mode control scheme in epilepsy treatment

2021 ◽  
pp. 014233122110507
Author(s):  
Moshu Qian ◽  
Zhen Zhang ◽  
Guanghua Zhong ◽  
Cuimei Bo
Keyword(s):  
Closed Loop ◽  
Controller Design ◽  
Sliding Mode ◽  
Tracking Error ◽  
Lyapunov Theory ◽  
Terminal Sliding Mode ◽  
Loop Control ◽  
Control Approach ◽  
Control Scheme ◽  
Loop Control System

In this paper, a closed-loop brain stimulation control problem is investigated using the nonsingular integral terminal sliding mode (NITSM) control approach. First, the thalamocortical model of epilepsy seizure is given, which is composed of the cortical PY-IN subnetwork and the subcortical RE-TC subsystem. Then, a nonsingular integral terminal sliding mode surface is designed utilizing the derived output tracking error, and the stability of the sliding mode dynamics is proved by Lyapunov approach. Furthermore, a disturbance observer (DOB) based NITSM controller design approach is proposed for the established thalamocortical model, and the reachability of the closed-loop control system under the designed controller is analyzed using Lyapunov theory. Finally, simulation results are given to illustrate the effectiveness and superiority of the designed control scheme.

scholarly journals Consistency of Control Performance in 3D Overhead Cranes under Payload Mass Uncertainty

Electronics ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 657 ◽  
Author(s):  
Uyen Tu Thi Hoang ◽  
Hai Xuan Le ◽  
Nguyen Huu Thai ◽  
Hung Van Pham ◽  
Linh Nguyen
Keyword(s):  
Closed Loop ◽  
Sliding Mode ◽  
Lyapunov Theory ◽  
Control Technique ◽  
Control Performance ◽  
Loop Control ◽  
Closed Loop Control System ◽  
Loop Control System ◽  
Mass Uncertainty ◽  
Payload Mass

The paper addresses the problem of effectively and robustly controlling a 3D overhead crane under the payload mass uncertainty, where the control performance is shown to be consistent. It is proposed to employ the sliding mode control technique to design the closed-loop controller due to its robustness, regardless of the uncertainties and nonlinearities of the under-actuated crane system. The radial basis function neural network has been exploited to construct an adaptive mechanism for estimating the unknown dynamics. More importantly, the adaptation methods have been derived from the Lyapunov theory to not only guarantee stability of the closed-loop control system, but also approximate the unknown and uncertain payload mass and weight matrix, which maintains the consistency of the control performance, although the cargo mass can be varied. Furthermore, the results obtained by implementing the proposed algorithm in the simulations show the effectiveness of the proposed approach and the consistency of the control performance, although the payload mass is uncertain.

Integral terminal sliding mode formation control of non-holonomic robots using leader follower approach

Robotica ◽  
2016 ◽  
Vol 35 (7) ◽  
pp. 1473-1487 ◽  
Author(s):  
Muhammad Asif ◽  
Muhammad Junaid Khan ◽  
Attaullah Y. Memon
Keyword(s):  
Formation Control ◽  
Sliding Mode ◽  
Tracking Error ◽  
Obstacle Detection ◽  
Lyapunov Theory ◽  
Terminal Sliding Mode ◽  
Loop Control ◽  
The Stability ◽  
Close Loop Control ◽  
Multi Robot

SUMMARYMulti-robot formation control has become an important area of research due to its advantages and applications. This paper presents multi-robot formation control using a leader–follower approach without considering the leader's velocity information or estimation. The leader–follower formation is formulated by incorporating the model uncertainties and disturbances. A novel formation controller is presented using integral terminal sliding mode (ITSM) control, which drives the formation tracking error convergence to zero in finite-time. The stability of the close-loop control scheme is verified by using Lyapunov theory. Furthermore, obstacle detection and avoidance are incorporated to avoid collision while maintaining the formation. The effectiveness of the proposed controller is verified and validated using sine and lamniscate curve trajectories. Moreover, the performance of the proposed ITSM formation controller is compared with the standard linear sliding mode (LSM) control.

Adaptive synchronization of uncertain fractional-order chaotic systems using sliding mode control techniques

2019 ◽  
Vol 234 (1) ◽  
pp. 3-9 ◽  
Author(s):  
Bahram Yaghooti ◽  
Ali Siahi Shadbad ◽  
Kaveh Safavi ◽  
Hassan Salarieh
Keyword(s):  
Control System ◽  
Sliding Mode Control ◽  
Fractional Order ◽  
Chaotic Systems ◽  
Closed Loop ◽  
Sliding Mode ◽  
Closed Loop Control ◽  
Loop Control ◽  
Closed Loop Control System ◽  
Loop Control System

In this article, an adaptive nonlinear controller is designed to synchronize two uncertain fractional-order chaotic systems using fractional-order sliding mode control. The controller structure and adaptation laws are chosen such that asymptotic stability of the closed-loop control system is guaranteed. The adaptation laws are being calculated from a proper sliding surface using the Lyapunov stability theory. This method guarantees the closed-loop control system robustness against the system uncertainties and external disturbances. Eventually, the presented method is used to synchronize two fractional-order gyro and Duffing systems, and the numerical simulation results demonstrate the effectiveness of this method.

scholarly journals Antidisturbance Vibration Suppression of the Aerial Refueling Hose during the Coupling Process

2017 ◽  
Vol 2017 ◽  
pp. 1-20
Author(s):  
Zikang Su ◽  
Honglun Wang
Keyword(s):  
Vibration Suppression ◽  
Sliding Mode ◽  
Permanent Magnet Synchronous Motor ◽  
Tracking Error ◽  
Measurement Noise ◽  
Aerial Refueling ◽  
Terminal Sliding Mode ◽  
Multiple Disturbances ◽  
Noise Simulation ◽  
Control Scheme

In autonomous aerial refueling (AAR), the vibration of the flexible refueling hose caused by the receiver aircraft’s excessive closure speed should be suppressed once it appears. This paper proposed an active control strategy based on the permanent magnet synchronous motor (PMSM) angular control for the timely and accurate vibration suppression of the flexible refueling hose. A nonsingular fast terminal sliding-mode (NFTSM) control scheme with adaptive extended state observer (AESO) is proposed for PMSM take-up system under multiple disturbances. The states and the “total disturbance” of the PMSM system are firstly reconstituted using the AESO under the uncertainties and measurement noise. Then, a faster sliding variable with tracking error exponential term is proposed together with a special designed reaching law to enhance the global convergence speed and precision of the controller. The proposed control scheme provides a more comprehensive solution to rapidly suppress the flexible refueling hose vibration in AAR. Compared to other methods, the scheme can suppress the flexible hose vibration more fleetly and accurately even when the system is exposed to multiple disturbances and measurement noise. Simulation results show that the proposed scheme is competitive in accuracy, global rapidity, and robustness.

scholarly journals Output Feedback Adaptive Dynamic Surface Sliding-Mode Control for Quadrotor UAVs with Tracking Error Constraints

Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-23 ◽  
Author(s):  
Guoqiang Zhu ◽  
Sen Wang ◽  
Lingfang Sun ◽  
Weichun Ge ◽  
Xiuyu Zhang
Keyword(s):  
Sliding Mode Control ◽  
Output Feedback ◽  
Controller Design ◽  
Sliding Mode ◽  
Tracking Error ◽  
Control Process ◽  
Nonlinear Observer ◽  
Dynamic Surface ◽  
Mode Control ◽  
Control Scheme

In this paper, a fuzzy adaptive output feedback dynamic surface sliding-mode control scheme is presented for a class of quadrotor unmanned aerial vehicles (UAVs). The framework of the controller design process is divided into two stages: the attitude control process and the position control process. The main features of this work are (1) a nonlinear observer is employed to predict the motion velocities of the quadrotor UAV; therefore, only the position signals are needed for the position tracking controller design; (2) by using the minimum learning technology, there is only one parameter which needs to be updated online at each design step and the computational burden can be greatly reduced; (3) a performance function is introduced to transform the tracking error into a new variable which can make the tracking error of the system satisfy the prescribed performance indicators; (4) the sliding-mode surface is introduced in the process of the controller design, and the robustness of the system is improved. Stability analysis proved that all signals of the closed-loop system are uniformly ultimately bounded. The results of the hardware-in-the-loop simulation validate the effectiveness of the proposed control scheme.

Robust control for hypersonic vehicles with parametric and unstructured uncertainties

2017 ◽  
Vol 232 (13) ◽  
pp. 2369-2380 ◽  
Author(s):  
Hao Liu ◽  
Deyuan Liu ◽  
Jianxiang Xi ◽  
Yao Yu
Keyword(s):  
Robust Control ◽  
Closed Loop ◽  
Hypersonic Vehicles ◽  
Frequency Range ◽  
Parameter Uncertainties ◽  
Loop Control ◽  
Control Approach ◽  
Closed Loop Control System ◽  
Loop Control System ◽  
Multiple Uncertainties

A robust flight controller is proposed for the longitudinal model of generic hypersonic vehicles, whose dynamics involves nonlinearities, parameter uncertainties, and unstructured uncertainties. The proposed longitudinal controller is developed based on the standard [Formula: see text] theory and the robust compensating approach. The robust compensating approach is introduced to reduce the influences of multiple uncertainties and nonlinearities on the closed-loop control system. Compared to the [Formula: see text] control theory, these influences in the whole frequency range can be restrained. Theoretical analysis and numerical simulation results are presented to illustrate the tracking performance properties of the designed robust control approach.

scholarly journals Fractional-Order Sliding Mode Control of Overhead Cranes   

2020 ◽  
Vol 31 (1) ◽  
pp. 68-76
Keyword(s):  
Sliding Mode Control ◽  
Fractional Order ◽  
Closed Loop ◽  
Control Structure ◽  
Adaptive System ◽  
Sliding Mode ◽  
Lyapunov Theory ◽  
Closed Loop System ◽  
Control Approach ◽  
Mode Control

We constitute a control system for overhead crane with simultaneous motion of trolley and payload hoist to destinations and suppression of payload swing. Controller core made by sliding mode control (SMC) assures the robustness. This control structure is inflexible since using fixed gains. For overcoming this weakness, we integrate variable fractional-order derivative into SMC that leads to an adaptive system with adjustable parameters. We use Mittag–Leffler stability, an enhanced version of Lyapunov theory, to analyze the convergence of closed-loop system. Applying the controller to a practical crane shows the efficiency of proposed control approach. The controller works well and keeps the output responses consistent despite the large variation of crane parameters.

scholarly journals Using Interval Analysis to Compute the Invariant Set of a Nonlinear Closed-Loop Control System

Algorithms ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 262 ◽  
Author(s):  
Swantje Romig ◽  
Luc Jaulin ◽  
Andreas Rauh
Keyword(s):  
Interval Analysis ◽  
Closed Loop ◽  
Sliding Mode ◽  
Initial Conditions ◽  
Invariant Sets ◽  
Control Synthesis ◽  
Closed Loop Control ◽  
Loop Control ◽  
Loop Control System ◽  
Bézout’S Identity

In recent years, many applications, as well as theoretical properties of interval analysis have been investigated. Without any claim for completeness, such applications and methodologies range from enclosing the effect of round-off errors in highly accurate numerical computations over simulating guaranteed enclosures of all reachable states of a dynamic system model with bounded uncertainty in parameters and initial conditions, to the solution of global optimization tasks. By exploiting the fundamental enclosure properties of interval analysis, this paper aims at computing invariant sets of nonlinear closed-loop control systems. For that purpose, Lyapunov-like functions and interval analysis are combined in a novel manner. To demonstrate the proposed techniques for enclosing invariant sets, the systems examined in this paper are controlled via sliding mode techniques with subsequently enclosing the invariant sets by an interval based set inversion technique. The applied methods for the control synthesis make use of a suitably chosen Gröbner basis, which is employed to solve Bézout’s identity. Illustrating simulation results conclude this paper to visualize the novel combination of sliding mode control with an interval based computation of invariant sets.

scholarly journals Profile-Tracking-Based Adaptive Guidance Law against Maneuvering Targets

2019 ◽  
Vol 2019 ◽  
pp. 1-17
Author(s):  
Jingshuai Huang ◽  
Hongbo Zhang ◽  
Guojian Tang ◽  
Weimin Bao
Keyword(s):  
Convergence Rate ◽  
Sliding Mode ◽  
Tracking Error ◽  
Small Neighborhood ◽  
Terminal Sliding Mode ◽  
Control Approach ◽  
Maneuvering Target ◽  
Guidance Law ◽  
Adaptive Guidance ◽  
The One

For the terminal guidance problem of a missile intercepting a maneuvering target, a profile-tracking-based adaptive guidance law is proposed with inherent continuity in this paper. To flexibly and quantitatively control the convergence rate of the line-of-sight rate, a standard tracking profile is designed where the convergence rate is analytically given. Then, a nonsingular fast terminal sliding-mode control approach is used to track the profile. By estimating the square of the upper bound of target maneuver, an adaptive term is constructed to compensate the maneuver. Therefore, no information of target acceleration is required in the derived law. Stability analysis shows that the tracking error can converge to a small neighborhood of zero in finite time. Furthermore, a guidance-command-conversion scheme is presented to convert the law into the one appropriate for endoatmospheric interceptions. Simulation results indicate that the proposed law is effective and outperforms existing guidance laws.

Fuzzy impedance-based control with fast terminal sliding mode force control loop for a series elastic actuator system

2021 ◽  
pp. 014233122110436
Author(s):  
Seyed Ali Moafi ◽  
Farid Najafi
Keyword(s):  
Force Control ◽  
Fuzzy Logic Controller ◽  
Sliding Mode ◽  
Control Loop ◽  
Terminal Sliding Mode ◽  
Control Approach ◽  
Series Elastic Actuator ◽  
Control Scheme ◽  
Fast Terminal Sliding Mode ◽  
Series Elastic

This paper proposes a robust control scheme to accomplish the interaction control problem between a series elastic actuator (SEA) and a flexible environment. The adaptability of the controller to unknown variations and robustness of the controller during interaction of the system with environment are the main aims. The control scheme is based on a fuzzy impedance control approach and consists of an inner fast terminal sliding mode force control loop. An experimental setup is designed to prove the efficiency of the developed controller. The experimental results confirm that the proposed fuzzy logic controller guarantees the sensitivity of the controlled system to unpredictable variations. Moreover, by applying the fast terminal sliding mode algorithm for the inner force control loop, the system has faster convergence to the reference path compared with similar control methods found in the literature.

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