Nonsingular terminal sliding mode control of nonlinear second-order systems with input saturation (original) (raw)
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Scientia Iranica
This paper investigates fixed-time nonsingular terminal sliding mode control of second-order nonlinear systems in the presence of matched and mismatched disturbances. Using estimation of the mismatched disturbance estimated by a fixed-time disturbance observer, a novel nonlinear dynamic sliding surface is designed. The convergence time of the closed-loop system including disturbance observer and control system is guaranteed to be uniform with respect to initial conditions. Moreover, the proposed controller avoids chattering phenomenon by producing a continuous control signal.
Finite-time nonsingular terminal sliding mode control: A time setting approach
Proceedings of the Institution of Mechanical Engineers, Part I: Journal of Systems and Control Engineering, 2019
This article proposes a combination of linear and nonlinear sliding surfaces to design a new structure for terminal sliding mode control, capable of accepting a definite final time as an input data. The structures of both single-input-single-output and multi-input-multi-output systems are expressed. The controller operates in two modes: first, reaching the states to linear sliding surface, defining control parameters and rise time; second, switching to nonlinear sliding surface and defining a convergence time. Sum of rise time and convergence time, both of which as inputs, sets the final time. The control gains are adaptively tuned and parameter uncertainty in dynamics is considered in the design. The proposed method is implemented theoretically and experimentally on Scout robot in point-to-point motion and trajectory tracking. The results are compared to conventional terminal sliding mode control and finite-time state-dependent Riccati equation to assess the improvement.
Terminal sliding mode control strategy design for second-order nonlinear system
IECON 2012 - 38th Annual Conference on IEEE Industrial Electronics Society, 2012
This study mainly focuses on the terminal sliding mode control (TSMC) strategy design, including an adaptive terminal sliding mode control (ATSMC) and an exact-estimator based terminal sliding mode control (ETSMC) for second-order nonlinear dynamical systems. In the ATSMC system, an adaptive bound estimation for the lump uncertainty is proposed to ensure the system stability. On the other hand, an exact estimator is designed for exact estimating system uncertainties to solve the trouble of chattering phenomena caused by a sign function in ATSMC law in despite of the utilization of a fixed value or an adaptive tuning algorithm for the lumped uncertainty bound. The effectiveness of the proposed control schemes can be verified in numerical simulations.
Non-singular terminal sliding mode control and its application for robot manipulators
2001
A global non-singular terminal sliding mode controller for second order uncertain nonlinear dynamic systems, which enables enables finite time reachibility and elimination of the singularity problem associated with conventional terminal sliding mode control. The tracking precision problem is also explored. The relationship between the tracking precision and the width of the saturation function used for elimination of chattering is formulated. The proposed controller is then applied to the control of a rigid manipulator. Simulation results are presented to validate the analysis.
Nonsingular Terminal Sliding Mode Control Based on Novel Reaching Law for Nonlinear Uncertain System
Applied Mechanics and Materials, 2013
Novel reaching law to nonsingular terminal sliding mode control for the control of the second order nonlinear uncertain system is introduced in this paper. The problems of singularity, chattering and slow convergence of the terminal sliding mode control, and verify the stability of the new controller is analyzed. Due to the premise of eliminating the singular value in the nonsingular terminal sliding mode control, the new reaching law based on the power reaching law enables the finite time convergence of the system equilibrium. By applying the new controller to the inverted pendulum system, the sliding surface had been proved fast and the system chattering had been reduced at the same time. Simulation results indict that the system converges to the equilibrium in a short time and the proposed method is feasible and effective.
Mathematics, 2021
In this study, an adaptive nonsingular finite time control technique based on a barrier function terminal sliding mode controller is proposed for the robust stability of nth-order nonlinear dynamic systems with external disturbances. The barrier function adaptive terminal sliding mode control makes the convergence of tracking errors to a region near zero in the finite time. Moreover, the suggested method does not need the information of upper bounds of perturbations which are commonly applied to the sliding mode control procedure. The Lyapunov stability analysis proves that the errors converge to the determined region. Last of all, simulations and experimental results on a complex new chaotic system with a high Kaplan–Yorke dimension are provided to confirm the efficacy of the planned method. The results demonstrate that the suggested controller has a stronger tracking than the adaptive controller and the results are satisfactory with the application of the controller based on chaot...
Fast second-order sliding mode control design based on lyapunov function
We design a new kind of fast terminal sliding mode controller for second-order uncertain systems with a single control input. In contrast to the reported techniques, which are based on the Terminal Sliding Mode Control, the proposed controller design is based on Lyapunov methods. Sufficient conditions are given to ensure the finite-time stability of the close-loop system with the proposed discontinuous controller. The performance is compared with others Fast Terminal Sliding Mode controllers by means of a simulation example.
Nonsingular fast terminal sliding-mode control for nonlinear dynamical systems
International Journal of Robust and Nonlinear Control, 2010
This paper investigates fast finite-time control of nonlinear dynamics using terminal sliding-mode (TSM) scheme. Some new norms of fast TSM strategies are proposed, and a faster convergence rate is established in comparison with the conventional fast TSM. A novel concept of nonsingular fast TSM, which is able to avoid the possible singularity during the control phase, is adopted in the robust high-precision control of uncertain nonlinear systems. Numerical simulation on a two-link rigid robot manipulator demonstrates the effectiveness of the proposed algorithm.
Mathematical Problems in Engineering, 2014
A continuous nonsingular fast terminal sliding mode (NFTSM) control scheme with the extended state observer (ESO) and the tracking differentiator (TD) is proposed for second-order uncertain SISO nonlinear systems. The system’s disturbances and states can be estimated by introducing the ESO, then the disturbances are compensated effectively, and the ideal transient process of the system can be arranged based on TD to provide the target tracking signal and its high-order derivatives. The proposed controller obtains finite-time convergence property and keeps good robustness of sliding mode control (SMC) for disturbances. Moreover, compared with conventional SMC, the proposed control law is continuous and no chattering phenomenon exists. The property of system stability is guaranteed by Lyapunov stability theory. The simulation results show that the proposed method can be employed to shorten the system reaching time, improve the system tracking precision, and suppress the system chatter...