Adaptive non-singular terminal sliding mode controller: new design for full control of the quadrotor with external disturbances

2016 ◽  
Vol 39 (3) ◽  
pp. 371-383 ◽  
Author(s):  
Alireza Modirrousta ◽  
Mahdi Khodabandeh
Keyword(s):  
Position Control ◽  
Sliding Mode ◽  
Control Input ◽  
External Disturbances ◽  
Terminal Sliding Mode ◽  
Nonlinear Disturbance Observer ◽  
Tuning Method ◽  
Regular Control ◽  
Control Scheme ◽  
Sliding Mode Controllers

This paper proposes two different adaptive robust sliding mode controllers for attitude, altitude and position control of a quadrotor. Firstly, it proposes a backstepping non-singular terminal sliding mode control with an adaptive algorithm that is applied to the quadrotor for free chattering, finite time convergence and robust aims. In this control scheme instead of regular control input, the derivative of the control input is achieved from a non-singular terminal second-layer sliding surface. An adaptive tuning method is utilized to deal with the external disturbances whose upper bounds are not required to be known in advance in the inner loop. Secondly, a nonlinear disturbance observer based on the integral sliding mode with adaptive gains is proposed for position control, which is known as the outer loop. Stability and robustness of the proposed controller are proved by using the classical Lyapunov criterion. The simulation results demonstrate the validation of the proposed control scheme.

Flexible air-breathing hypersonic vehicle control based on a novel non-singular fast terminal sliding mode control and nonlinear disturbance observer

2016 ◽  
Vol 231 (11) ◽  
pp. 2132-2145 ◽  
Author(s):  
Xiaoqian Yang ◽  
Jian Li ◽  
Yi Dong
Keyword(s):  
Sliding Mode Control ◽  
Sliding Mode ◽  
Hypersonic Vehicle ◽  
Terminal Sliding Mode Control ◽  
Terminal Sliding Mode ◽  
Nonlinear Disturbance Observer ◽  
Mode Control ◽  
Control Scheme ◽  
Fast Terminal Sliding Mode ◽  
Nonlinear Disturbance

A new control scheme for flexible air-breathing hypersonic vehicle is designed in this paper based on non-singular fast terminal sliding mode control and nonlinear disturbance observer. The proposed control scheme is derived from basic back-stepping method, which is capable of handling the higher-order nonlinear system, and a novel terminal sliding mode control method is designed for the last step to promise the finite time convergence and improve the steady-state precision. Meanwhile, a command filter is used to avoid the “explosion of complexity” in traditional back-stepping method. To overcome inevitable uncertainties as well as cross couplings between flexible and rigid modes, NDO is introduced to estimate diverse uncertainties. Thus flexible modes and uncertainties can be suppressed simultaneously. The convergence of overall closed-loop system states is proved via Lyapunov analysis. Numerical simulations show the effectiveness and advantages of the proposed control strategy.

scholarly journals Robust attitude tracking control scheme for a multi-body spacecraft using a radial basis function network and terminal sliding mode

2014 ◽  
Vol 24 (5) ◽  
Author(s):  
CHANGQING YUAN ◽  
YANHUA ZHONG ◽  
JINGRUI ZHANG ◽  
HONGBUO LI ◽  
GUOJUN YANG ◽  
...  
Keyword(s):  
Basis Function ◽  
Sliding Mode ◽  
Radial Basis Function Network ◽  
Robust Controller ◽  
External Disturbances ◽  
Terminal Sliding Mode ◽  
Attitude Tracking ◽  
Control Scheme ◽  
Multi Body ◽  
Function Network

We present a novel robust control scheme that deals with multi-body spacecraft attitude tracking problems. The control scheme consists of a radial basis function network (RBFN) and a robust controller. By using the finite time convergence property of the terminal sliding mode (TSM), we derive a new online learning algorithm for updating all the parameters of the RBFN that ensures the RBFN has fast approximation for the parameter uncertainties and external disturbances. We design a robust controller to compensate RBFN approximation errors and realise the anticipative stability and performance properties. We can also achieve closed-loop system stability using Lyapunov stability theory.No detailed knowledge of the non-linear dynamics of the spacecraft is required at any point in the entire design process, and the proposed robust scheme is simple and effective and can be applied to more complex systems. Simulation results demonstrate the good tracking characteristics of the proposed control scheme in the presence of inertial uncertainties and external disturbances.

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

2021 ◽  
Vol 2021 ◽  
pp. 1-10 ◽  
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.

Adaptive intelligent terminal sliding mode controller for stabilizing a chaotic plasma torch system

2020 ◽  
pp. 107754632095952
Author(s):  
Behrooz Rezaie ◽  
Safa Khari
Keyword(s):  
Plasma Torch ◽  
Hybrid Control ◽  
Sliding Mode ◽  
Sliding Mode Controller ◽  
Sliding Surface ◽  
External Disturbances ◽  
Neural Controller ◽  
Terminal Sliding Mode ◽  
Control Scheme ◽  
Hybrid Control Scheme

In this article, a novel adaptive intelligent control scheme is proposed to stabilize a chaotic nonlinear system with unknown dynamics in the presence of uncertainties and external disturbances. The proposed control scheme is a combination of terminal sliding mode, adaptive, and neural controllers. Terminal sliding mode control provides appropriate finite-time stability and robustness against uncertainties and external disturbances. A neural controller is used to provide suitable control action to eliminate chattering when the sliding surface is close to zero. For this purpose, a fuzzy module with simple rules is used to change the contributions of two neural and terminal sliding mode controllers, that is, when the sliding surface has a value around zero, the neural controller will take the control of the system to reduce chattering, and when the sliding surface is far from the zero region, the terminal sliding mode controller will control the system. Moreover, to cope with the unknown dynamics of the system, an online adaptive neural network is also used to approximate the unknown dynamics of the system. This hybrid control scheme is capable to decrease the contribution of the terminal sliding mode in the convergence region of the sliding surface which leads to the elimination of chattering. The combination of the several techniques to use the advantages of all the methods makes the proposed hybrid control scheme as an effective and practical scheme. Simulation results on a chaotic plasma torch system indicate the efficiency of the proposed control scheme in chattering elimination, high convergence, and also show the superior performance compared with the existing methods in the presence of disturbance and uncertainty.

scholarly journals Terminal Sliding Mode Control with Unidirectional Auxiliary Surfaces for Hypersonic Vehicles Based on Adaptive Disturbance Observer

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Naibao He ◽  
Changsheng Jiang ◽  
Bin Jiang ◽  
Qian Gao
Keyword(s):  
Attitude Control ◽  
Disturbance Observer ◽  
Sliding Mode ◽  
Robust Adaptive Control ◽  
Hypersonic Vehicles ◽  
Control Performance ◽  
External Disturbances ◽  
Terminal Sliding Mode ◽  
Control Scheme ◽  
Observer Model

A novel flight control scheme is proposed using the terminal sliding mode technique, unidirectional auxiliary surfaces and the disturbance observer model. These proposed dynamic attitude control systems can improve control performance of hypersonic vehicles despite uncertainties and external disturbances. The terminal attractor is employed to improve the convergence rate associated with the critical damping characteristics problem noted in short-period motions of hypersonic vehicles. The proposed robust attitude control scheme uses a dynamic terminal sliding mode with unidirectional auxiliary surfaces. The nonlinear disturbance observer is designed to estimate system uncertainties and external disturbances. The output of the disturbance observer aids the robust adaptive control scheme and improves robust attitude control performance. Finally, simulation results are presented to illustrate the effectiveness of the proposed terminal sliding mode with unidirectional auxiliary surfaces.

Fuzzy Adaptive Nonsingular Terminal Sliding Mode Control for a Three-Links Spatial Robot

2013 ◽  
Vol 655-657 ◽  
pp. 1048-1052
Author(s):  
Sheng Bin Hu ◽  
Wen Hua Lu ◽  
Xing Yuan Zhang ◽  
Hai Rong Xu ◽  
Da Min Cao
Keyword(s):  
Sliding Mode Control ◽  
Control Method ◽  
Sliding Mode ◽  
Lyapunov Theory ◽  
Sliding Mode Controller ◽  
Control Input ◽  
Terminal Sliding Mode ◽  
Mode Control ◽  
Nonsingular Terminal Sliding Mode ◽  
Control Scheme

To achieve high performance tracing control of the three-links spatial robot, a nonsingular terminal fuzzy sliding mode control method is proposed in this paper. Firstly, the control method can efficiently avoid the singularity of the generally terminal sliding mode controller through designing nonsingular terminal sliding mode surface. Secondly, to diminish the chattering in the control input, a fuzzy controller is designed to adjust the gain of nonsingular terminal sliding mode controller according to the normal of nonsingular terminal sliding mode surface. The stability of the control scheme is verified by using Lyapunov theory. The proposed controller is then applied to the control of a three-links spatial robot. Simulation results show the validity of the proposed control scheme.

Design of adaptive optimal robust control for two-flexible-link manipulators in the presence of matched uncertainties

2020 ◽  
pp. 107754632093202
Author(s):  
Hamid Reza Shafei ◽  
Mohsen Bahrami ◽  
Heidar Ali Talebi
Keyword(s):  
Sliding Mode Control ◽  
Sliding Mode ◽  
Flexible Link ◽  
External Disturbances ◽  
Terminal Sliding Mode ◽  
Control Approach ◽  
Mode Control ◽  
Nonsingular Terminal Sliding Mode ◽  
Control Scheme ◽  
The Stability

This study uses a comprehensive control approach to deal with the trajectory tracking problem of a two-flexible-link manipulator subjected to model uncertainties. Because the control inputs of two-flexible-link manipulators are less than their state variables, the proposed controller should be able to tackle the stated challenge. Practically speaking, there is only a single control signal for each joint, which can be used to suppress link deflections and control joint trajectories. To achieve this objective, a novel optimal robust control scheme, with an updated gain under the adaptive law, has been developed in this work for the first time. In this regard, a nonsingular terminal sliding mode control approach is used as the robust controller and a control Lyapunov function is used as the optimal control law, to benefit from the advantages of both methods. To systematically deal with system uncertainties, an adaptive law is used to update the gain of nonsingular terminal sliding mode control. The advantage of this approach over the existing methods is that it not only can robustly and stably control an uncertain nonlinear system against external disturbances but also can optimally solve a quadratic cost function (e.g. minimization of control effort). The Lyapunov stability theory has been applied to verify the stability of the proposed approach. Moreover, to show the superiority of this method, the computer simulation results of the proposed method have been compared with those of an adaptive sliding mode control scheme. This comparison shows that the presented approach is capable of optimizing the control inputs while achieving the stability of the examined two-flexible-link manipulator in the presence of model uncertainties and external disturbances.

scholarly journals Robust Adaptive Relative Position and Attitude Control for Noncooperative Spacecraft Hovering under Coupled Uncertain Dynamics

2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
Jianghui Liu ◽  
Haiyang Li ◽  
YaKun Zhang ◽  
Jianyong Zhou ◽  
Lin Lu ◽  
...  
Keyword(s):  
Model Uncertainty ◽  
Attitude Control ◽  
Degrees Of Freedom ◽  
Sliding Mode ◽  
Target System ◽  
External Disturbances ◽  
Terminal Sliding Mode ◽  
Tuning Method ◽  
Modified Rodrigues Parameters ◽  
Uncertain Dynamics

The control of body-fixed hovering over noncooperative target, as one of the key problems of relative motion control between spacecrafts, is studied in the paper. The position of the chaser in the noncooperative target’s body coordinate system is required to remain unchanged, and the attitude of the chaser and the target must be synchronized at the same time. Initially, a six-degrees-of-freedom-coupled dynamic model of a chaser relative to a target is established, and relative attitude dynamics is described through using modified Rodrigues parameters (MRP). Considering the model uncertainty and external disturbances of the noncooperative target system, an adaptive nonsingular terminal sliding mode (NTSM) controller is designed. Adaptive tuning method is used to overcome the effects of the model uncertainty and external disturbances. The upper bounds of the model uncertainty and external disturbances are not required to be known in advance. The actual control law is continuous and chatter-free, which is obtained by integrating the discontinuous derivative control signal. Finally, these theoretical results are verified by numerical simulation.

scholarly journals Observer-based robust integral of the sign of the error control of class I of underactuated mechanical systems: Theory and real-time experiments

2021 ◽  
pp. 014233122110313
Author(s):  
Afef Hfaiedh ◽  
Ahmed Chemori ◽  
Afef Abdelkrim
Keyword(s):  
Real Time ◽  
Error Control ◽  
Degrees Of Freedom ◽  
Sliding Mode ◽  
Mechanical Systems ◽  
Class I ◽  
Control Input ◽  
Underactuated Mechanical Systems ◽  
Control Scheme ◽  
And Performance

In this paper, the control problem of a class I of underactuated mechanical systems (UMSs) is addressed. The considered class includes nonlinear UMSs with two degrees of freedom and one control input. Firstly, we propose the design of a robust integral of the sign of the error (RISE) control law, adequate for this special class. Based on a change of coordinates, the dynamics is transformed into a strict-feedback (SF) form. A Lyapunov-based technique is then employed to prove the asymptotic stability of the resulting closed-loop system. Numerical simulation results show the robustness and performance of the original RISE toward parametric uncertainties and disturbance rejection. A comparative study with a conventional sliding mode control reveals a significant robustness improvement with the proposed original RISE controller. However, in real-time experiments, the amplification of the measurement noise is a major problem. It has an impact on the behaviour of the motor and reduces the performance of the system. To deal with this issue, we propose to estimate the velocity using the robust Levant differentiator instead of the numerical derivative. Real-time experiments were performed on the testbed of the inertia wheel inverted pendulum to demonstrate the relevance of the proposed observer-based RISE control scheme. The obtained real-time experimental results and the obtained evaluation indices show clearly a better performance of the proposed observer-based RISE approach compared to the sliding mode and the original RISE controllers.

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