Adaptive Terminal Sliding Mode Research Articles

Adaptive terminal sliding mode control subject to input nonlinearity for synchronization of chaotic gyros

Under the existence of system uncertainties, external disturbances, and input nonlinearity, complete synchronization and anti-synchronization between two chaotic gyros are achieved by introducing a novel adaptive terminal sliding mode (ATSM) controller. In the literature, by taking account of input nonlinearity, the magnitudes of bounded nonlinear dynamics of synchronous error system were required in the designed sliding mode controller. In this study, the proposed ATSM controller associated with time-varying feedback gains can tackle nonlinear dynamics according to the novel adaptive rules. These feedback gains are not necessary to be determined in advance but updated by the adaptive rules without known the magnitudes of bounded nonlinear dynamics, system uncertainties, and external disturbances. Sufficient conditions to guarantee stable synchronization are given in the sense of the Lyapunov stability theorem, and the numerical simulations are performed to verify the effectiveness of presented schemes.

Design of an Adaptive Terminal Dynamic Sliding Mode Controller for Anti-Ship Missiles

Adaptive dynamic sliding mode control strategy for the overload control of anti-ship missiles using Lyapunov stability theory is proposed. By using a function augmented sliding hyperplane, it is guaranteed that the output tracking error converges to zero in finite time. In addition, an adaptive method is adopted to attenuate the uncertainties. The simulation shows validity of the proposed method.

Adaptive Terminal Sliding Mode Control of Opto-Electronic Stabilized Platform Based on Acceleration Feedback

In order to overcome the effect of the friction and the nonlinear disturbance in the high precision Opto-electronic(EO) servo-stabilized platform system, adaptive terminal sliding mode control (ATSMC) base on acceleration feedback is introduced in the system. Different to traditional sliding mode control, a terminal sliding surface is introduced to assure finite convergent time of control errors on the surface. In addition, due to unknown bound of uncertainty, an adaptive law is derived to compensate the effect. As a result, in this control strategy, the ATSMC controller was used to improve the tracking accuracy in the position loop; the acceleration feedback controller was introduced to compensate for friction torque and disturbance. The simulation results show the proposed control scheme to be effective.

Adaptive Terminal Sliding Mode Tracking Control for Rigid Robotic Manipulators with Uncertain Dynamics.

A robust adaptive terminal sliding mode tracking control is proposed for rigid robotic manipulators. First, it is shown that, when a rigid robotic manipulator is treated as a partially known system, the system uncertainty is not only related to the model properties but also to the structure of the controllers. It is also proved that, if the control input vector does not contain the acceleration signals, the system uncertainty is upper bounded by a positive function of the position and velocity measurements. The property is very useful for the design of robust and adaptive controllers where only position and velocity measurements are available. Second, an MIMO terminal sliding mode is defined for the error dynamics of the robot control system, and an adaptive mechanism is introduced to estimate the upper bounds of system uncertainty in the Lyapunov sense. The estimates are then used as controller parameters so that the effects of uncertain dynamics can be eliminated and a finite time error convergence can be guaranteed. A simulation is given in support of the proposed control scheme.