Neuro-Sliding Control for Underwater ROV’s Subject to Unknown Disturbances

Proposed in this paper is a model-free and chattering-free second order sliding mode control (2nd-SMC) in combination with a backpropagation neural network (BP-NN) control scheme for underwater vehicles to deal with external disturbances (i.e., ocean currents) and parameter variations caused, for instance, by the continuous interchange of tools. The compound controller, here called the neuro-sliding control (NSC), takes advantage of the 2nd-SMC robustness and fast response to drive the position tracking error to zero. Simultaneously, the BP-NN contributes with its capability to estimate and to compensate online the hydrodynamic variations of the vehicle. When a change in the vehicle’s hydrodynamics occurs, the 2nd-SMC may no longer be able to compensate for the variations since its feedback gains are tuned for a different condition; thus, in order to preserve the desired performance, it is necessary to re-tune the feedback gains, which a cumbersome and time consuming task. To solve this, a viable choice is to implement a BP-NN control scheme along with the 2nd-SMC that adds or removes energy from the system according to the current condition it is in, in order to keep, or even improve, its performance. The effectiveness of the proposed compound controller was supported by experiments carried out on a mini-ROV.

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Robust Synchronization of Incommensurate Fractional-Order Chaotic Systems via Second-Order Sliding Mode Technique

Journal of Applied Mathematics ◽

10.1155/2013/321253 ◽

2013 ◽

Vol 2013 ◽

pp. 1-11 ◽

Cited By ~ 4

Author(s):

Hua Chen ◽

Wen Chen ◽

Binwu Zhang ◽

Haitao Cao

Keyword(s):

Fractional Order ◽

Chaotic Systems ◽

Controller Design ◽

Sliding Mode ◽

Second Order ◽

External Disturbances ◽

Globally Asymptotically Stable ◽

Control Scheme ◽

Chattering Free ◽

Second Order Sliding Mode

A second-order sliding mode (SOSM) controller is proposed to synchronize a class of incommensurate fractional-order chaotic systems with model uncertainties and external disturbances. Based on the chattering free SOSM control scheme, it can be rigorously proved that the dynamics of the synchronization error is globally asymptotically stable by using the Lyapunov stability theorem. Finally, numerical examples are provided to illustrate the effectiveness of the proposed controller design approach.

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Robust Model-Free Control for Robot Manipulator under Actuator Dynamics

Mathematical Problems in Engineering ◽

10.1155/2020/7417314 ◽

2020 ◽

Vol 2020 ◽

pp. 1-11

Author(s):

Dorsaf Elleuch ◽

Tarak Damak

Keyword(s):

Sliding Mode ◽

Robot Manipulator ◽

Lyapunov Theory ◽

Pd Control ◽

External Disturbances ◽

Actuator Dynamics ◽

Model Free ◽

Robust Model ◽

Parameter Variations ◽

Model Free Control

An intelligent proportional-derivative sliding mode controller (i-PDSMC) is presented to overcome the unmodeled complexity of the robot manipulator under an actuator. i-PDSMC is a free model intelligent control based on the ultralocal, sliding mode, and PD control structure. A stability condition is determined by the Lyapunov theory. A comparative study between a classical PD, an intelligent PD control, and i-PDSMC is done through a robot manipulator under actuators. The simulation results prove that the proposed controller is more robust to trajectory tracking under parameter variations and external disturbances.

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Adaptive Fixed-Time Sliding Mode Control for Uncertain Twin-Rotor System with Experimental Validation

Complexity ◽

10.1155/2019/6582405 ◽

2019 ◽

Vol 2019 ◽

pp. 1-11

Author(s):

Linwu Shen ◽

Qiang Chen ◽

Meiling Tao ◽

Xiongxiong He

Keyword(s):

Sliding Mode ◽

Setting Time ◽

Tracking Error ◽

Fixed Time ◽

External Disturbances ◽

Rotor Systems ◽

Time Control ◽

Control Scheme ◽

Comparative Results ◽

Twin Rotor

This paper proposes an adaptive fixed-time control scheme for twin-rotor systems subject to the inertia uncertainties and external disturbances. First of all, a fixed-time sliding mode surface is constructed and the corresponding controller is developed such that the fixed-time uniform ultimate boundedness of the sliding variable and tracking error could be guaranteed simultaneously, and the setting time is independent of the initial values. The adaptive update laws are developed to estimate the upper bounds of the lumped uncertainties and external disturbances such that no prior knowledge on the system uncertainties and disturbances is required. Finally, a twin-rotor platform is constructed to verify the effectiveness of proposed scheme. Comparative results show better position tracking performance of the proposed control scheme.

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RBFNN-Based Singularity-Free Terminal Sliding Mode Control for Uncertain Quadrotor UAVs

Computational Intelligence and Neuroscience ◽

10.1155/2021/3576783 ◽

2021 ◽

Vol 2021 ◽

pp. 1-10 ◽

Cited By ~ 1

Author(s):

Meiling Tao ◽

Xiongxiong He ◽

Shuzong Xie ◽

Qiang Chen

Keyword(s):

Finite Time ◽

Sliding Mode ◽

Auxiliary Function ◽

External Disturbances ◽

Terminal Sliding Mode ◽

Finite Time Convergence ◽

Time Control ◽

Control Scheme ◽

Unknown Disturbances ◽

Quadrotor Unmanned Aerial Vehicles

In this article, a singularity-free terminal sliding mode (SFTSM) control scheme based on the radial basis function neural network (RBFNN) is proposed for the quadrotor unmanned aerial vehicles (QUAVs) under the presence of inertia uncertainties and external disturbances. Firstly, a singularity-free terminal sliding mode surface (SFTSMS) is constructed to achieve the finite-time convergence without any piecewise continuous function. Then, the adaptive finite-time control is designed with an auxiliary function to avoid the singularity in the error-related inverse matrix. Moreover, the RBFNN and extended state observer (ESO) are introduced to estimate the unknown disturbances, respectively, such that prior knowledge on system model uncertainties is not required for designing attitude controllers. Finally, the attitude and angular velocity errors are finite-time uniformly ultimately bounded (FTUUB), and numerical simulations illustrated the satisfactory performance of the designed control scheme.

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Robust neural network control of MEMS gyroscope using adaptive sliding mode compensator

Robotica ◽

10.1017/s026357471400160x ◽

2014 ◽

Vol 34 (3) ◽

pp. 497-512 ◽

Cited By ~ 4

Author(s):

Juntao Fei ◽

Yuzheng Yang

Keyword(s):

Neural Network ◽

Upper Bound ◽

Tracking Control ◽

Sliding Mode ◽

Tracking Error ◽

Modeling Error ◽

External Disturbances ◽

Mems Gyroscope ◽

Control Scheme ◽

The Impact

SUMMARYA new robust neural sliding mode (RNSM) tracking control scheme using radial basis function (RBF) neural network (NN) is presented for MEMS z-axis gyroscope to achieve robustness and asymptotic tracking error convergence. An adaptive RBF NN controller is developed to approximate and compensate the large uncertain system dynamics, and a robust compensator is designed to eliminate the impact of NN modeling error and external disturbances for guaranteeing the asymptotic stability property. Moreover, another RBF NN is employed to learn the upper bound of NN modeling error and external disturbances, so the prior knowledge of the upper bound of system uncertainties is not required. All the adaptive laws in the RNSM control system are derived in the same Lyapunov framework, which can guarantee the stability of the closed loop system. Comparative numerical simulations for an MEMS gyroscope are investigated to verify the effectiveness of the proposed RNSM tracking control scheme.

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Finite-time model-free trajectory tracking control for overhead cranes subject to model uncertainties, parameter variations and external disturbances

Transactions of the Institute of Measurement and Control ◽

10.1177/0142331219830157 ◽

2019 ◽

Vol 41 (12) ◽

pp. 3516-3525 ◽

Cited By ~ 10

Author(s):

Menghua Zhang

Keyword(s):

Trajectory Tracking ◽

Finite Time ◽

Sliding Mode ◽

Overhead Crane ◽

Model Uncertainties ◽

Asymptotic Results ◽

External Disturbances ◽

Trajectory Tracking Control ◽

Model Free ◽

Parameter Variations

The payload mass and the cable length are always different/uncertain for various transportation tasks and external disturbances that accompany industrial overhead crane systems. In addition, existing control methods can obtain merely asymptotic results. To solve the aforementioned problems, an accurate model-free trajectory tracking controller subject to finite time convergence for overhead crane systems is proposed based on the suitably defined non-singular terminal sliding vector. Moreover, the proposed controller is absolutely continuous, addressing the limitations and shortcomings of the traditional sliding mode control. Lyapunov techniques are used to prove that the proposed controller guarantees finite-time tracking result and the finite time T is calculated. Simulation and experimental results are included to demonstrate the robustness of the proposed controller with respect to model uncertainties, parameter variations and external disturbances.

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Control of an IPMC Soft Actuator Using Adaptive Full-Order Recursive Terminal Sliding Mode

Actuators ◽

10.3390/act10020033 ◽

2021 ◽

Vol 10 (2) ◽

pp. 33

Author(s):

Romina Zarrabi Ekbatani ◽

Ke Shao ◽

Jasim Khawwaf ◽

Hai Wang ◽

Jinchuan Zheng ◽

...

Keyword(s):

Sliding Mode ◽

External Disturbance ◽

Tracking Error ◽

Working Environment ◽

Parametric Uncertainties ◽

Metal Composite ◽

External Disturbances ◽

Terminal Sliding Mode ◽

Positioning Accuracy ◽

Soft Actuator

The ionic polymer metal composite (IPMC) actuator is a kind of soft actuator that can work for underwater applications. However, IPMC actuator control suffers from high nonlinearity due to the existence of inherent creep and hysteresis phenomena. Furthermore, for underwater applications, they are highly exposed to parametric uncertainties and external disturbances due to the inherent characteristics and working environment. Those factors significantly affect the positioning accuracy and reliability of IPMC actuators. Hence, feedback control techniques are vital in the control of IPMC actuators for suppressing the system uncertainty and external disturbance. In this paper, for the first time an adaptive full-order recursive terminal sliding-mode (AFORTSM) controller is proposed for the IPMC actuator to enhance the positioning accuracy and robustness against parametric uncertainties and external disturbances. The proposed controller incorporates an adaptive algorithm with terminal sliding mode method to release the need for any prerequisite bound of the disturbance. In addition, stability analysis proves that it can guarantee the tracking error to converge to zero in finite time in the presence of uncertainty and disturbance. Experiments are carried out on the IPMC actuator to verify the practical effectiveness of the AFORTSM controller in comparison with a conventional nonsingular terminal sliding mode (NTSM) controller in terms of smaller tracking error and faster disturbance rejection.

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A computationally efficient adaptive robust control scheme for a quad-rotor transporting cable-suspended payloads

Proceedings of the Institution of Mechanical Engineers Part G Journal of Aerospace Engineering ◽

10.1177/09544100211013617 ◽

2021 ◽

pp. 095441002110136

Author(s):

Nasim Ullah ◽

Irfan Sami ◽

Wang Shaoping ◽

Hamid Mukhtar ◽

Xingjian Wang ◽

...

Keyword(s):

Robust Control ◽

Fractional Order ◽

Sliding Mode ◽

Adaptive Robust Control ◽

Computationally Efficient ◽

Control Scheme ◽

Control Schemes ◽

Adaptive Laws ◽

Unknown Disturbances ◽

The Stability

This article proposes a computationally efficient adaptive robust control scheme for a quad-rotor with cable-suspended payloads. Motion of payload introduces unknown disturbances that affect the performance of the quad-rotor controlled with conventional schemes, thus novel adaptive robust controllers with both integer- and fractional-order dynamics are proposed for the trajectory tracking of quad-rotor with cable-suspended payload. The disturbances acting on quad-rotor due to the payload motion are estimated by utilizing adaptive laws derived from integer- and fractional-order Lyapunov functions. The stability of the proposed control systems is guaranteed using integer- and fractional-order Lyapunov theorems. Overall, three variants of the control schemes, namely adaptive fractional-order sliding mode (AFSMC), adaptive sliding mode (ASMC), and classical Sliding mode controllers (SMC)s) are tested using processor in the loop experiments, and based on the two performance indicators, namely robustness and computational resource utilization, the best control scheme is evaluated. From the results presented, it is verified that ASMC scheme exhibits comparable robustness as of SMC and AFSMC, while it utilizes less sources as compared to AFSMC.

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

International Journal of Aerospace Engineering ◽

10.1155/2017/9837349 ◽

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.

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Trajectory tracking for quadrotor UAV transporting cable-suspended payload in wind presence

Transactions of the Institute of Measurement and Control ◽

10.1177/0142331218774606 ◽

2018 ◽

Vol 41 (5) ◽

pp. 1243-1255 ◽

Cited By ~ 8

Author(s):

Baharnaz Barikbin ◽

Ahmad Fakharian

Keyword(s):

Sliding Mode Control ◽

Trajectory Tracking ◽

Sliding Mode ◽

Continuous Control ◽

Mode Control ◽

Control Signals ◽

Unknown Disturbances ◽

Chattering Free ◽

Aerial Vehicle ◽

Integral Version

In this paper, trajectory tracking for a quadrotor unmanned aerial vehicle (UAV) is considered in the presence of a cable-suspended payload and wind as unknown disturbances. It is assumed that the wind disturbance is slowly time varying and affects quadrotor position and orientation independently. Nonlinear robust strategies, such as backstepping and sliding mode control could be used for trajectory tracking; however, they fail to stabilize the system in the presence of payload or wind, or both together. We have proposed a combined backstepping and super-twisting integral sliding mode strategy to stabilize the system. Conventional sliding mode control suggests discontinuous control signals and suffers from the chattering phenomenon whereas its super-twisting integral version suggests continuous control signals, which makes it implementable and chattering free.

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