Terminal sliding mode control with non-symmetric input saturation for vibration suppression of electrostatically actuated nanobeams in the presence of Casimir force

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.

Download Full-text

Synchronization of a Non-Equilibrium Four-Dimensional Chaotic System Using a Disturbance-Observer-Based Adaptive Terminal Sliding Mode Control Method

Entropy ◽

10.3390/e22030271 ◽

2020 ◽

Vol 22 (3) ◽

pp. 271 ◽

Cited By ~ 7

Author(s):

Shaojie Wang ◽

Amin Yousefpour ◽

Abdullahi Yusuf ◽

Hadi Jahanshahi ◽

Raúl Alcaraz ◽

...

Keyword(s):

Sliding Mode Control ◽

Chaotic System ◽

Disturbance Observer ◽

Sliding Mode ◽

Input Saturation ◽

Control Input ◽

Terminal Sliding Mode Control ◽

Terminal Sliding Mode ◽

Mode Control ◽

And Control

In this paper, dynamical behavior and synchronization of a non-equilibrium four-dimensional chaotic system are studied. The system only includes one constant term and has hidden attractors. Some dynamical features of the governing system, such as invariance and symmetry, the existence of attractors and dissipativity, chaotic flow with a plane of equilibria, and offset boosting of the chaotic attractor, are stated and discussed and a new disturbance-observer-based adaptive terminal sliding mode control (ATSMC) method with input saturation is proposed for the control and synchronization of the chaotic system. To deal with unexpected noises, an extended Kalman filter (EKF) is implemented along with the designed controller. Through the concept of Lyapunov stability, the proposed control technique guarantees the finite time convergence of the uncertain system in the presence of disturbances and control input limits. Furthermore, to decrease the chattering phenomena, a genetic algorithm is used to optimize the controller parameters. Finally, numerical simulations are presented to demonstrate the performance of the designed control scheme in the presence of noise, disturbances, and control input saturation.

Download Full-text