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    • List of Articles Amir Hossein Hassanabadi

      • Open Access Article

        1 - A Fuzzy Fault Tolerant Controller Design Based on Virtual Sensor for a DC Microgrid
        Alireza Galavizh Amir Hossein Hassanabadi
        In this paper, a fault tolerant control (FTC) method is presented for a DC microgrid with constant power loads (CPLs) which is prone to sensor faults. The main idea of this FTC method is based on hiding the sensor faults from the controller point of view using a suitabl More
        In this paper, a fault tolerant control (FTC) method is presented for a DC microgrid with constant power loads (CPLs) which is prone to sensor faults. The main idea of this FTC method is based on hiding the sensor faults from the controller point of view using a suitable virtual sensor. After presenting the nonlinear model of the system, the model is then converted to a Takagi-Sugeno (TS) fuzzy representation. The nominal controller is designed for the fuzzy model in the form of a state feedback and the states are estimated using a suitable observer. In the event of a sensor fault detection, the effects of the fault in the control loop are compensated by a virtual sensor. The gains of the controller, the virtual sensor and the observer are designed using related linear matrix inequalities (LMIs) and applying some appropriate LMI regions to achieve appropriate performance. The proposed method is an active fault tolerant control (AFTC) strategy in which the virtual sensor hides the sensor faults from the controller and the observer. In this method, from the controller's point of view, the faulty system plus the virtual sensor acts like a healthy system, and the nominal controller continues to its work without the need to be reconfigured. The efficiency of the proposed method is demonstrated in a constant-load DC micro‌grid modelled using electrical elements. Manuscript profile
      • Open Access Article

        2 - An LPV Approach to Sensor Fault Diagnosis of Robotic Arm
        Amir Hossein Sabbaghan Amir Hossein Hassanabadi
        One of the major challenges in robotic arms is to diagnosis sensor fault. To address this challenge, this paper presents an LPV approach. Initially, the dynamics of a two-link manipulator is modelled with a polytopic linear parameter varying structure and then by using More
        One of the major challenges in robotic arms is to diagnosis sensor fault. To address this challenge, this paper presents an LPV approach. Initially, the dynamics of a two-link manipulator is modelled with a polytopic linear parameter varying structure and then by using a descriptor system approach and a robust design of a suitable unknown input observer by means of pole placement method along with linear matrix inequalities, in addition to providing an estimate of state variables for using in state feedback, the detection, isolation, and identification of sensor faults in the manipulator are addressed. The proposed observer provides a robust estimate of the faults along with attenuating the disturbance effects. Further, the desired angles of the joints are calculated for achieving the desired trajectory of the robot’s end-effector using the inverse kinematics and by designing a suitable state feedback law with integral mode, the reference signals are tracked. The sufficient condition for stability of the closed-loop system is obtained as a set of linear matrix inequalities at the vertices of the system. The efficiency and effectiveness of the control system, along with the designed fault diagnosis unit, are shown using numerical simulations. Manuscript profile