scholarly journals Robust Continuous Control for a Class of Mechanical Systems Based on Nonsingular Terminal Sliding Mode

IEEE Access ◽  
2020 ◽  
Vol 8 ◽  
pp. 19297-19305 ◽  
Author(s):  
Raul Rascon ◽  
David I. Rosas ◽  
Julio C. Rodriguez-Quinonez
Keyword(s):  
Sliding Mode ◽  
Mechanical Systems ◽  
Continuous Control ◽  
Terminal Sliding Mode ◽  
Nonsingular Terminal Sliding Mode

scholarly journals Finite-Time Spacecraft’s Soft Landing on Asteroids Using PD and Nonsingular Terminal Sliding Mode Control

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Keping Liu ◽  
Fengxia Liu ◽  
Shenquan Wang ◽  
Yuanchun Li
Keyword(s):  
Sliding Mode ◽  
Landing Site ◽  
Open Loop ◽  
Sliding Mode Controller ◽  
Reference Trajectory ◽  
Continuous Control ◽  
Soft Landing ◽  
Terminal Sliding Mode ◽  
Nonsingular Terminal Sliding Mode ◽  
Motion Characteristics

This paper presents a continuous control law of probe, which consists of PD (proportional-derivative) controller and nonsingular terminal sliding mode controller for probe descending and landing phases, respectively, in the case of the asteroid irregular shape and low gravity. The probe dynamic model is deduced in the landing site coordinate system firstly. Then the reference trajectory based on optimal polynomial in open-loop state is designed, with the suboptimal fuel consumption. Taking into account different characteristics of phases, PD controller and nonsingular terminal sliding mode controller can be employed in the descending phase and the landing phase, respectively, to track the designed reference trajectory. The controller which used the corresponding control methods can meet the motion characteristics and requirements of each stage. Finally simulation experiments are carried out to demonstrate the effectiveness of the proposed method, which can ensure the safe landing of probe and achieve continuous control.

Super-twisting disturbance observer-based finite- time attitude stabilization of flexible spacecraft subject to complex disturbances

2018 ◽  
Vol 25 (5) ◽  
pp. 1008-1018 ◽  
Author(s):  
Ruidong Yan ◽  
Zhong Wu
Keyword(s):  
Attitude Control ◽  
Disturbance Observer ◽  
Sliding Mode ◽  
State Variables ◽  
Attitude Dynamics ◽  
Attitude Control System ◽  
Terminal Sliding Mode ◽  
Nonlinear Disturbance Observer ◽  
Attitude Stabilization ◽  
Nonsingular Terminal Sliding Mode

There exist complex disturbances in the attitude control system of flexible spacecrafts, such as space environmental disturbances, flexible vibrations, inertia uncertainties, payload motions, etc. To suppress the effects of these disturbances on the performance of attitude stabilization, a super-twisting disturbance observer (STDO)-based nonsingular terminal sliding mode controller (NTSMC) is proposed in this paper. First, STDO is designed for a second-order dynamical system constructed by applying the lumped disturbance and its integral as state variables, and applying the integral as virtual measurement. Since the virtual measurement is obtained by integrating the inverse attitude dynamics, STDO not only avoids the differential operation of angular velocity, but also fully utilizes the information of a nonlinear model. By combining STDO with NTSMC, a composite controller is designed to achieve high-accuracy spacecraft attitude stabilization. Since most of the disturbances are compensated for by a STDO-based feedforward compensator, only a small switching gain is required to deal with the residual disturbances and uncertainties. Thus, the chattering phenomenon of the controller can be alleviated to a great extent. Finally, numerical simulations for the comparison between STDO-based NTSMC and nonlinear disturbance observer-based NTSMC are carried out in the presence of complex disturbances to verify the effectiveness of the proposed approach.

scholarly journals Position Tracking Control for Permanent Magnet Linear Motor via Continuous-Time Fast Terminal Sliding Mode Control

2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
Wei Gao ◽  
Xiuping Chen ◽  
Haibo Du ◽  
Song Bai
Keyword(s):  
Sliding Mode Control ◽  
Continuous Time ◽  
Control Method ◽  
Sliding Mode ◽  
Terminal Sliding Mode Control ◽  
Terminal Sliding Mode ◽  
Mode Control ◽  
Nonsingular Terminal Sliding Mode ◽  
Fast Terminal Sliding Mode ◽  
Permanent Magnet Linear Motor

For the position tracking control problem of permanent magnet linear motor, an improved fast continuous-time nonsingular terminal sliding mode control algorithm based on terminal sliding mode control method is proposed. Specifically, first, for the second-order model of position error dynamic system, a new continuous-time fast terminal sliding surface is introduced and an improved continuous-time fast terminal sliding mode control law is proposed. Then rigorous theoretical analysis is provided to demonstrate the finite-time stability of the closed-loop system by using the Lyapunov function. Finally, numerical simulations are given to verify the effectiveness and advantages of the proposed fast nonsingular terminal sliding mode control method.

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