Yazar "Sarigecili, Mehmet Ilteris" seçeneğine göre listele

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    A cascade fuzzy adaptive based interaction torque control of a pneumatically actuated forearm rehabilitation robot under disturbance effects
    (Sage Publications Ltd, 2024) Dagdelen, Mustafa; Sarigecili, Mehmet Ilteris; Ozbek, Necdet Sinan
    In this study, an intelligent adaptive interaction torque control for a pneumatically actuated forearm rehabilitation robot has been proposed. The main objective is to provide a haptic environment that ensures stable interaction torque fields at changing levels. To achieve this goal, a cascade fuzzy adaptive controller, that is specifically tailored to handle varying levels of interaction torque and ensure stability throughout the rehabilitation process, has been designed. To improve the efficiency of the controller, non-linear friction torque identification of the pneumatic actuator based on changing operating conditions has been conducted. Parallel to this, a user motion intention detection algorithm has been designed to provide compliant, safe and suitable human-robot interactions. The disturbance cases have been considered to make the system robust to unknown conditions. Stability analysis has been performed, specifically focusing on the boundary-input boundary-output (BIBO) stability conditions. In order to demonstrate the superior performance of the proposed cascade fuzzy adaptive algorithm, a cascade PID algorithm has also been meticulously designed for comparison. Numerous experimental validation tests involving a healthy user were conducted in a Hardware-in-the-Loop environment, focusing on torque trajectory tracking performance. The proposed control technique exhibited improved convergence dynamics compared to the cascade PID algorithm, yielding mean absolute error levels of 0.0218 Nm and 0.099 Nm for target interaction torque under disturbance-free and disturbed conditions, respectively.
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    A Method for Adjusting Moment Input on an Exoskeleton Robot with Fixed Linear Actuators
    (Springer International Publishing Ag, 2017) Ozgur, Huseyin Emre; Sarigecili, Mehmet Ilteris
    Patients who lose walking ability get rehabilitation services that consist of repeated movements of the lower limbs such that the patients can regain their ability to move. Unfortunately, the change in the number of patients and need for gait rehabilitation is inversely proportional with the number of physiotherapists. There are many robotic rehabilitation systems available which are generally expensive. There is a direct need for an inexpensive rehabilitation robot that can be afforded (or can be reached) by the majority of people. As a solution to this problem, a pneumatically actuated, 4 degrees of freedom exoskeleton robot for the movement of a patient in sagittal plane and which can be used together with a body weight support system has been developed. The novelty of the proposed approach lies in how pneumatic linear actuation is used to adjust the torque required to move a limb for a particular patient. The proposed system has also a simpler control technique than other available complicated and more advanced systems.
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    A new compressible flow model for pneumatic directional control valves
    (Sage Publications Ltd, 2023) Dagdelen, Mustafa; Sarigecili, Mehmet Ilteris; Ozbek, Necdet Sinan
    In this study, a new compressible flow model for small orifice openings in pneumatic proportional directional control valves has been proposed. It is crucial to precisely control pneumatic valves over all control ranges; yet, conventional flow models fail around the closed position of the valve. The main deficit of the existing studies in the literature is to assume constant values for the parameters of the flow model over changing operating conditions. It has been demonstrated that these rough assumptions are insufficient in precisely predicting the mass flow rate, particularly for small orifice openings. An enhanced experimental setup has been introduced to improve the effectiveness of the proposed model. The cracking pressure ratio and parameters of the model have been identified with experimental method. In the proposed model, new empirical coefficients have been established after a thorough investigation of the impact of supply pressure on the flow behavior of the valve. Validation studies of the model in both the filling and exhausting states of the valve have been carried out at various supply pressures and orifice openings, yielding rather promising modeling performances. In validation tests, the real pressure and the pressure produced by new model have been compared, and good agreement has been achieved with 0.0039% absolute error. According to the findings, the proposed improved flow model can be selected in precision pneumatic control applications.