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Fast rotating machines require special attention to ensure accurate rotor placement within the air gap. For this reason, the active magnetic bearings (AMB) system is used to levitate the rotor in the air gap using an electromagnetic feedback control force. The contact-less support AMB system improves the rotor dynamic performance and helps in the success of machine operations. However, the control design for the five degrees-of-freedom (DOF) AMB system is intricate because of its complex nonlinear dynamics. Moreover, these systems are often subjected to model uncertainties, harmonic disturbances, and sensor noises. Therefore, this paper proposes a robust control strategy using an adaptive second-order non-singular fast terminal sliding mode control (SMC) design. The proposed control law employs the higher-order SMC scheme to alleviate the chattering problem from the discontinuous SMC input, which would otherwise restrict its practical applicability. Further, a non-singular fast terminal sliding surface is selected to achieve a faster system response. The adaptive law estimates the switching gain to relax the upper bound assumption of disturbance. The theoretical stability analysis of the proposed methodology proves the finite-time convergence of system states to a small residual bound in the neighborhood of zero. The numerical analysis with a comparative study is also carried out to illustrate the efficacy of the proposed strategy.INDEX TERMS Uncertain nonlinear system, regulation control, sliding mode control, input chattering, adaptive gain, practical finite-time stability, homogeneity theory, Lyapunov theory.ABDULRAHMAN ALTURKI received the B.Sc. degree (Hons.

The kingdom of Saudi Arabia produces almost 400 varieties, is the largest producer of dates in the worlds in dates fruit industries. The date's industries have facing problems in date grading and sorting during harvesting and agriculture products industries. Since human experts have some limitations such as tedious and timing delay consuming the processing delay as a result of date products costly. The computer vision algorithms are used to reduce the powers of mankind by automatically detect and classify an image. The main aim of the computer vision-based algorithms for data fruits grading and sorting is to make the procedure fully automated and reduce human interference. The computer vision algorithm uses RGB pictures, which automatically abstracts the aforesaid exterior date class arrangements. Based on the extracted algorithms, the proposed vision-based machine automatically classifies dates into three different quality based categories (class A, B, and C) defined by the user. The paper studied the accuracy of the computer vision-based algorithm based on pre-selected date fruits samples from different field in Al-Qassim, Sudi Arabia. The experimental grades classification illustrated that the proposed algorithm is able to sort the date's fruits up to 99% precisely.

The implementation of the Orthogonal Frequency Division Multiplexing (OFDM) can be achieved using Inverse Discrete Cosine Transform (IDCT), and DCT instead of Inverse Discrete Fourier Transform (IDFT), and DFT. The Carrier Frequency Offset (CFO) is the main issue of the OFDM system. One of the tools to mitigate the CFO effect and improve the Bit-Error-Rate (BER) performance is the equalization procedure. Also, the 1-Dimension (1-D), and 2-Dimension (2-D) burst errors can be mitigated using a chaotic interleaver in the OFDM system. This consequently improves the BER performance. In this paper, we propose a Joint Low-Complexity Regularized Linear Zero Forcing (JLCRLZF) equalizer for the OFDM system based on DCT in addition to a chaotic interleaving scheme. The proposed equalizer depends on the concept of the banded-matrix approximation, and jointly performs the equalization and CFO compensation processes. Simulation results ensure the importance of the proposed JLCRLZF equalizer compared to other algorithms.