Adaptive finite-time back-stepping global sliding mode tracker of quad-rotor UAVs under model uncertainty, wind perturbation and input saturation

2021 ◽  
pp. 1-1
Author(s):  
Omid Mofid ◽  
Saleh Mobayen
Keyword(s):  
Model Uncertainty ◽  
Finite Time ◽  
Sliding Mode ◽  
Input Saturation ◽  
Wind Perturbation

Robust spacecraft attitude tracking control with integral terminal sliding mode surface considering input saturation

2018 ◽  
Vol 41 (2) ◽  
pp. 405-416 ◽  
Author(s):  
Haitao Chen ◽  
Shenmin Song ◽  
Xuehui Li
Keyword(s):  
Finite Time ◽  
Sliding Mode ◽  
External Disturbance ◽  
Input Saturation ◽  
External Disturbances ◽  
Terminal Sliding Mode ◽  
Modeling Uncertainty ◽  
Finite Time Convergence ◽  
Attitude Tracking ◽  
Attitude Tracking Control

This paper studies the finite time spacecraft attitude tracking control problem, while considering modeling uncertainty, external disturbances and control input saturation. A novel integral terminal sliding mode surface (ITSMS) is designed by combining the fast terminal sliding mode surface (FTSMS) with a low pass filter to achieve a fast finite time convergence rate for the control system, without input singularity. An auxiliary signal is used to compensate for the effects of actuator saturation. The basic controller is first formulated based on the ITSMS, fast-TSM-type reaching law and auxiliary system, in the presence of an external disturbance and input saturation. Then, an adaptive control procedure is introduced, which simultaneously handles modeling uncertainty and external disturbance, thereby creating an adaptive attitude tracking controller. The proposed controller provides a fast finite time convergence rate for the control system, based on the newly designed ITSMS, while simultaneously compensating for modeling uncertainty, external disturbances and input saturation, without restricting the parameter selection process nor requiring repeated differentiation of nonlinear functions. Finally, digital simulation results are presented and demonstrate the effectiveness of the proposed controllers.

scholarly journals Finite-Time Consensus Using an Adaptive Terminal Sliding Mode Control Subjected to Input Saturation

2020 ◽  
Vol 49 (3) ◽  
pp. 412-420
Author(s):  
Ming Ren ◽  
Heyan HUANG ◽  
Esmaiel Mirabdollahi
Keyword(s):  
Sliding Mode Control ◽  
Finite Time ◽  
Sliding Mode ◽  
Input Saturation ◽  
Upper Bounds ◽  
Terminal Sliding Mode Control ◽  
Terminal Sliding Mode ◽  
Mode Control ◽  
First Case ◽  
High Dependency

In this paper, finite-time consensus of double-integrator multi-agent systems is investigated. A new adaptive-terminal sliding mode control is proposed to satisfy the goal within a finite time by considering disturbances and input saturation. The problem is solved for two cases. In the first case, the agents are subjected to disturbances with known upper bounds and input saturation parameters. For the case, the control inputs are designed based on a terminal sliding mode technique to achieve the consensus aim within the finite time as a summation of settling and reaching times. Then, a fast terminal sliding mode control is applied and the control inputs are modified to reduce the high dependency of reaching times to initial speeds. In the second case, the upper disturbance bounds are unknown. To handle this problem, the control laws are adopted by an adaptive-terminal sliding mode method. The upper bounds of disturbances are estimated in the finite time. In both cases, the maximum control efforts are adjusted to always be less than the saturation boundary by optional tuning parameters. The proposed methods efficiency is verified by numerical simulations.

Adaptive anti-saturation fault-tolerant control of hypersonic vehicle with actuator faults

2018 ◽  
Vol 233 (6) ◽  
pp. 2066-2083
Author(s):  
Jing-guang Sun ◽  
Shen-Min Song ◽  
Peng-Li ◽  
Guan-qun Wu
Keyword(s):  
Finite Time ◽  
Control Method ◽  
Fault Tolerant ◽  
Sliding Mode ◽  
Input Saturation ◽  
Reference Signal ◽  
Fault Tolerant Control ◽  
Hypersonic Vehicle ◽  
Actuator Faults ◽  
The Impact

In this paper, related researches and analyses are conducted for the tracking problem of the hypersonic vehicle subject to external disturbances, actuator faults, and input saturation. Firstly, to achieve automatic adjustment of control gains and deal with the impact of dynamic failures of system without requiring prior knowledge of the fault, a new modified fast nonsingular terminal sliding manifold is proposed, and a fast adaptive finite time fault-tolerant controller is provided combining the adaptive control method and terminal sliding mode. Then, a fast adaptive finite time anti-saturation fault-tolerant controller is presented to further solve the problem of input saturation, under which both of the velocity and altitude can track respective reference signal with the actuator input constraint. Finally, the closed-loop stability under the proposed two adaptive fault-tolerant control schemes is analyzed, and numerical simulations of longitudinal model of the hypersonic vehicle are demonstrated to further confirm the effectiveness of the proposed approach.

Robust Intelligent Fault-Tolerant Based Finite-Time Attitude Control for Quadrotor UAV Without Angular Velocity Measurements

2021 ◽  
Author(s):  
Kang Liu ◽  
Rujing Wang
Keyword(s):  
Angular Velocity ◽  
Finite Time ◽  
Attitude Control ◽  
Fault Tolerant ◽  
Sliding Mode ◽  
External Disturbance ◽  
Input Saturation ◽  
Parametric Uncertainty ◽  
Accurate Information ◽  
Terminal Sliding Mode

Abstract This study considers the problem of finitetime attitude control for quadrotor unmanned aerial vehicles (UAVs) subject to parametric uncertainties, external disturbances, input saturation, and actuator faults. Under the strong approximation of radial basis function neural networks (RBFNN), an adaptive finitetime NN observer is first presented to obtain the accurate information of unavailable angular velocity. More importantly, an adaptive mechanism to adjust the output gain of the fuzzy logic system (FLS) is developed to avoid the selection of larger control gains, and can even work well without the prior information on the bound of the lumped disturbance. Based on the nonsingular fast terminal sliding mode manifold, a novel switching control law is designed by incorporating the adaptive FLS and fast continuous controller in order to remove the undesired chattering phenomenon and solve the negative effects induced from the parametric uncertainty, external disturbance, and actuator fault. To deal with the input saturation, an auxiliary system is constructed. The rigorous theoretical analysis is given to prove that all the signals in the closed-loop system are uniformly bounded, and tracking errors converge into bounded neighborhoods near the origin in finite time. Moreover, the issue of selecting control parameters is analyzed in detail. Last but not least, the comparative simulation results show the validity and feasibility of the proposed control framework.

Adaptive finite-time disturbance observer-based recursive fractional-order sliding mode control of redundantly actuated cable driving parallel robots under disturbances and input saturation

2021 ◽  
pp. 107754632110514
Author(s):  
Zhengsheng Chen ◽  
Xuesong Wang ◽  
Yuhu Cheng
Keyword(s):  
Sliding Mode Control ◽  
Fractional Order ◽  
Finite Time ◽  
Disturbance Observer ◽  
Sliding Mode ◽  
Estimation Error ◽  
Input Saturation ◽  
Parallel Robots ◽  
Mode Control ◽  
Redundantly Actuated

This paper proposed a novel finite-time disturbance observer-based recursive fractional-order sliding mode control (FTRFOSMC) algorithm under disturbances and input saturation for redundantly actuated cable driving parallel robots (RCDPRs). A recursive fractional-order sliding mode surface composed of the fractional-order non-singular fast terminal sliding mode function and an integral term is constructed, and the fast response convergence and high precision tracking performance can be obtained for the recursive characteristics of the proposed sliding mode surface; meanwhile, an auxiliary system is designed to overcome the adverse effects of the input saturation. Then, to compensate the model uncertainty and external disturbances, an adaptive finite-time disturbance observer is developed, and the estimation error can be stabilized in finite-time for unknown bound of the disturbance and its derivative. The stability of the proposed controller was investigated by the Lyapunov stability theory. Finally, numerical simulations with the software of the MATLAB/Simuink are conducted to verify the effectiveness of the proposed controller.

scholarly journals Finite-Time Tracking Control for a Class of MIMO Nonlinear Systems with Unknown Asymmetric Saturations

2017 ◽  
Vol 2017 ◽  
pp. 1-10
Author(s):  
Fu Mingyu ◽  
Xu Yujie
Keyword(s):  
Nonlinear Systems ◽  
Finite Time ◽  
Tracking Control ◽  
Sliding Mode ◽  
External Disturbance ◽  
Tracking Error ◽  
Input Saturation ◽  
Approximation Error ◽  
Time Interval ◽  
Mimo Nonlinear Systems

This paper addresses the problem of finite-time tracking control for multiple-input and multiple-output (MIMO) nonlinear systems with asymmetric saturations. A systematic approach is proposed to eliminate the effects of unmeasured external disturbances and unknown asymmetric saturations. In the proposed control strategy, a terminal sliding mode disturbance observer is provided to estimate the augmented disturbance (which contains the unknown asymmetric input saturation and external disturbance). The approximation error of the augmented disturbance can converge to zero in a fixed finite-time interval. Furthermore, a novel finite-time tracking control algorithm is developed to guarantee fast convergence of the tracking error. Compared with the existing results on finite-time tracking control, the chattering problem and the input saturation problem can be solved in a unified framework. Several simulations are given to demonstrate the effectiveness of the proposed approach.

scholarly journals Adaptive Backstepping Finite Time Attitude Control of Reentry RLV with Input Constraint

2014 ◽  
Vol 2014 ◽  
pp. 1-19 ◽  
Author(s):  
Fang Wang ◽  
Qun Zong ◽  
Bailing Tian
Keyword(s):  
Model Uncertainty ◽  
Finite Time ◽  
Sliding Mode ◽  
External Disturbance ◽  
Rotational Dynamics ◽  
Terminal Sliding Mode Control ◽  
Input Constraint ◽  
Adaptive Backstepping ◽  
Terminal Sliding Mode ◽  
Fast Terminal Sliding Mode

This paper presents the finite time attitude tracking control problem of reusable launch vehicle (RLV) in reentry phase under input constraint, model uncertainty, and external disturbance. A control-oriented model of rotational dynamics is developed and used for controller design for the complex coupling of the translational and rotational dynamics. Firstly, fast terminal sliding mode control is incorporated into backstepping control to design controller considering model uncertainty and external disturbance. The “explosion of terms” problem inherent in backstepping control is eliminated by a robust second order filter. Secondly, the control problem in the presence of input constraint is further considered, and a constrained adaptive backstepping fast terminal sliding mode control scheme is developed. At the control design level, adaptive law is employed to estimate the unknown norm bound of lumped uncertainty with the reduction of computational burden. The Lyapunov-based stability analysis of the closed-loop system is carried out. The control performance is presented via the simulation of six-degree-of-freedom (6-DOF) model of RLV.

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