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A dc-dc buck converter is an electronic circuit with wide application in power electronics. This converter acts as a nonlinear system then, it is necessary to use a robust controller to control and regulate the output voltage under load changes, circuit elements and other disturbances. In this paper, a new fast terminal sliding mode control (FTSMC) using the property of the terminal attraction as a function of the inverse tangent for buck DC-DC converter is provided. The performance of this new controller is compared with FTSMC common type in terms of output voltage convergence time and input control function structure. The superior property of this controller is low singular effect on the control function. Also, the controller has fast rate of convergence in different situations for output voltage stability in order to use in power electronic device of mechanical motion control systems such as types of robots and electric vehicle are pretty good. Simulation results confirm the proper performance of the new proposed fast terminal sliding mode control method compared to traditional fast terminal sliding mode converter for buck converter.

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The anti-lock braking system is one of the main factors to make safety in designing vehicles. The brake pressure control and desired slip tracking through severe braking cause safety in vehicles. Because of uncertainty in parameters and sever nonlinear factors, robust controller designing is suitable for this system. In this paper the types of sliding mode controller have been used to achieve a vehicle desired slip and its stop. Sliding surface and terminal attractions will be analyzed in all of the designed controllers. Also a new structure with high terminal attraction have been for the fast terminal sliding mode controller (FTSMC). The proposed method has reduced tracking error as well. In this paper, the performance of this controller is compared with normal terminal sliding mode controller and fast terminal sliding mode. Also all design parameters are determined to decrease error ratio using particle swarm optimization (PSO) algorithm. This method is suitable for solving complex optimized solution based on certain cost function. Simulation results with using MATLAB software, present better performance of the suggested controller in comparison with normal and fast terminal sliding mode controller.