scholarly journals Fixed-Time Third-Order Super-Twisting-like Sliding Mode Motion Control for Piezoelectric Nanopositioning Stage

Mathematics ◽  
2021 ◽  
Vol 9 (15) ◽  
pp. 1770
Author(s):  
Guangwei Wang ◽  
Bo Wang ◽  
Chengxi Zhang
Keyword(s):  
Sliding Mode ◽  
Initial Conditions ◽  
Fixed Time ◽  
Convergence Time ◽  
Continuous Control ◽  
Third Order ◽  
External Disturbances ◽  
Practical Applications ◽  
Chattering Free ◽  
Response Performance

This paper presents a novel third-order super-twisting-like integral sliding mode controller (3-ISMC) for trajectory tracking of nanopositioning applications. Different from traditional sliding mode control methods presenting with chattering problems, the proposed approach provides continuous control inputs, which brings much convenience for practical applications. Moreover, the fixed-time convergence of the proposed 3-ISMC is guaranteed independently of initial conditions. The estimation of the fixed convergence time and stability are derived based on the Lyapunov method. Simulation results demonstrate that the proposed controller exhibits chattering free and quick transient response performance for a piezoelectric nanopositioning system under model uncertainties and external disturbances.

scholarly journals Fixed-Time Trajectory Tracking Control of Autonomous Surface Vehicle with Model Uncertainties and Disturbances

Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Jiawen Cui ◽  
Haibin Sun
Keyword(s):  
Trajectory Tracking ◽  
Tracking Control ◽  
Sliding Mode ◽  
Fixed Time ◽  
Convergence Time ◽  
Model Uncertainties ◽  
External Disturbances ◽  
Trajectory Tracking Control ◽  
Integral Sliding Mode ◽  
Control Scheme

The issue of fixed-time trajectory tracking control for the autonomous surface vehicles (ASVs) system with model uncertainties and external disturbances is investigated in this paper. Particularly, convergence time does not depend on initial conditions. The major contributions include the following: (1) An integral sliding mode controller (ISMC) via integral sliding mode surface is first proposed, which can ensure that the system states can follow the desired trajectory within a fixed time. (2) Unknown external disturbances are absolutely estimated by means of designing a fixed-time disturbance observer (FTDO). By combining the FTDO and ISMC techniques, a new control scheme (FTDO-ISMC) is developed, which can achieve both disturbance compensation and chattering-free condition. (3) Aiming at reconstructing the unknown nonlinear dynamics and external disturbances, a fixed-time unknown observer (FTUO) is proposed, thus providing the FTUO-ISMC scheme that finally achieves trajectory tracking of ASVs with unknown parameters. Finally, simulation tests and detailed comparisons indicate the effectiveness of the proposed control scheme.

Predefined-time control for a horizontal takeoff and horizontal landing reusable launch vehicle

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Liang Zhang ◽  
Liang Jing ◽  
Liheng Ye ◽  
Xing Gao
Keyword(s):  
Disturbance Observer ◽  
Control Parameter ◽  
Sliding Mode ◽  
Fixed Time ◽  
Launch Vehicle ◽  
Convergence Time ◽  
Content Type ◽  
Reusable Launch Vehicle ◽  
Attitude Tracking ◽  
Tracking Controller

Purpose This paper aims to investigate the problem of attitude control for a horizontal takeoff and horizontal landing reusable launch vehicle. Design/methodology/approach In this paper, a predefined-time attitude tracking controller is presented for a horizontal takeoff and horizontal landing reusable launch vehicle (HTHLRLV). Firstly, the attitude tracking error dynamics model of the HTHLRLV is developed. Subsequently, a novel sliding mode surface is designed with predefined-time stability. Furthermore, by using the proposed sliding mode surface, a predefined-time controller is derived. To compensate the external disturbances or model uncertainties, a fixed-time disturbance observer is developed, and its convergence time can be defined as a prior control parameter. Finally, the stability of the proposed sliding mode surface and the controller can be proved by the Lyapunov theory. Findings In contrast to other fixed-time methods, this controller only requires three control parameters, and the convergence time can be predefined instead of being estimated. The simulation results also demonstrate the effectiveness of the proposed controller. Originality/value A novel predefined-time attitude tracking controller is developed based on the predefined-time sliding mode surface (SMS) and fixed-time disturbance observer (FxTDO). The convergence time of the system can be selected as a prior control parameter for SMS and FxTDO.

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

2018 ◽  
Vol 41 (5) ◽  
pp. 1243-1255 ◽  
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.

Robust Fixed-Time Integral Sliding Mode Control of a Nonlinear Hydraulic Turbine Regulating System

2020 ◽  
Vol 15 (3) ◽  
Author(s):  
Sunhua Huang ◽  
Jie Wang
Keyword(s):  
Sliding Mode Control ◽  
Sliding Mode ◽  
Hydraulic Turbine ◽  
Fixed Time ◽  
Convergence Time ◽  
Stable Operation ◽  
Phase System ◽  
Integral Sliding Mode ◽  
Mode Control ◽  
Time Integral

Abstract The hydraulic turbine regulating system (HTRS) plays an important role in the safe and stable operation of hydropower stations. In this paper, a fixed-time integral sliding mode controller (FTISMC) is designed to make the nonlinear HTRS with disturbances stable in a fixed time. The HTRS is a highly complex, strongly coupled, nonlinear nonminimum phase system, which can ensure the frequency and rotor angle of generator stability by adjusting the guide vane opening. In order to decouple the nonlinear HTRS, the input/output feedback linearization is applied to establish the relationship between the control input and the output of the HTRS. Based on sliding mode control (SMC) theory and fixed-time stability theory, FTISMC is proposed to stabilize the HTRS in a fixed time. Compared with the finite time control method (FTCM), the convergence time of nonlinear HTRS under FTISMC is independent of initial conditions and can be exactly estimated. Meanwhile, the integral sliding surface can avoid singularity, thus eliminating the chattering phenomenon. Finally, the numerical simulation is implemented to demonstrate the superior performances of the proposed FTISMC than the existing PID, SMC, and FTMC.

New fixed-time sliding mode control for a mismatched second-order system

2020 ◽  
pp. 014233122095230
Author(s):  
Guo Jianguo ◽  
Yang Shengjiang
Keyword(s):  
Sliding Mode Control ◽  
Sliding Mode ◽  
Initial Conditions ◽  
Nonlinear Function ◽  
Fixed Time ◽  
Second Order ◽  
Order System ◽  
Time Stability ◽  
Mode Control ◽  
Mismatched Uncertainties

A fixed-time sliding mode control (FTSMC) method is proposed for a second-order system with mismatched uncertainties in this paper. A new sliding mode, which is insensitive to the mismatched disturbance, is present to eliminate the effect of mismatched uncertainties by adopting the differentiable nonlinear function, and to obtain the fixed time stability independent of initial conditions by using the fraction-order function. In order to improve the performance of control system, the extended disturbance-observer-based fixed-time sliding mode control (EDO-FTSMC) approach is investigated to obtain the fixed-time stability subject to the mismatched uncertainties. Finally, the performance of the proposed control method is illustrated to compare other control approaches with numerical simulation results and application examples.

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

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
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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