An efficient approach for digital secure communication using adaptive backstepping fast terminal sliding mode control

In this work, a simple robust controller is developed for digital secure communication between two different chaotic systems (Duffing-Holmes oscillator and chaotic gyro) with uncertainties, external disturbances, and unknown parameters in a finite time by combining adaptive backstepping and terminal sliding mode approaches. The terminal sliding mode control (TSM) provides faster convergence and higher-precision control than the conventional sliding control. However, not only the original TSM encountered singularity problem but also it needs a prior knowledge about the system to be controlled. To address these issues, a fast non-singular TSM is developed, and in the core of the proposed approach, Chebyshev polynomials are used to approximate the nonlinearities of the master and slave systems. As a result of applying the proposed approach, the synchronization and the stability of the closed-loop control system are achieved. The numerical simulation results demonstrate the effectiveness of the proposed approach. (C) 2019 Elsevier Ltd. All rights reserved.