Browsing by Author "Samir Zeghlache"

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    Fault Tolerant Control Based on Adaptive Fuzzy Global Fast Dynamic Terminal Sliding Mode for Actuators Failures in an Octorotor UAV
    (2021) Abdelmoula Saggai; Samir Zeghlache; Loutfi Benyettou
    This work presents a reliable fault-tolerant tracking control system (FTTCS) for actuator faults in a octorotor unmanned aerial vehicle. The proposed FTTCS is designed based on adaptive fuzzy global fast dynamic terminal sliding mode control (AFGFDTSMC) that guarantees the global asymptotic stability of a octorotor system. To mitigate the negative impacts of model uncertainties and enhance system robustness in faulty operation, an adaptive fuzzy system is incorporated into the global fast dynamic terminal sliding mode control (GFDTSMC) scheme for adaptively identifying the model uncertainties online and compensate the actuator faults effect. Lyapunov stability analysis proofs that the developed control method design maintains the stability in the closed loop dynamics of octorotor UAV in faulty operation. Simulation results show that the proposed (FTTCS) enables the octorotor to track the desired reference commands in the presence of actuator faults with satisfactory performance
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    Sampling Rate Optimization for Improving the Cascaded Integrator Comb Filter Characteristics
    (Université de M'sila, 2020) Raouf Amrane; Youcef Brik; Samir Zeghlache; Mohamed Ladjal; Djamel Chicouche
    The cascaded integrator comb (CIC) filters are characterized by coefficient less and reduced hardware requirement, which make them an economical finite impulse response (FIR) class in many signal processing applications. They consist of an integrator section working at the high sampling rate and a comb section working at the low sampling rate. However, they don’t have well defined frequency response. To remedy this problem, several structures have been proposed but the performance is still unsatisfactory. Thence, this paper deals with the improvement of the CIC filter characteristics by optimizing its sampling rate. This solution increases the performance characteristics of CIC filters by improving the stopband attenuation and ripple as well as the passband droop. Also, this paper presents a comparison of the proposed method with some other existing structures such as the conventional CIC, the sharpened CIC, and the modified sharpened CIC filters, which has proven the effectiveness of the proposed method.