Mechatronics Engineering

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    Inductance Measurement Methods for Surface-Mount Permanent Magnet Machines
    (IEEE Transactions on Instrumentation and Measurement, 2023) Ertan, H. Bülent ; Şahin, İlker
    Analytical performance estimation of a permanent magnet (PM) motor requires an accurate equivalent circuit model. In a lumped electrical model of a PM motor, resistance and inductances appear as passive elements, which are used to represent the phase winding resistance, inductance, core loss, etc. There is currently no available standard for parameter measurement of PM motors. In the literature, there are many studies on inductance measurement. However, they are applied to different types of motors. The purpose of this study is to evaluate those different inductance measurement methods, on the same motors, to identify whether they lead to the same result. Also, it was aimed to find out the difficulties involved in the measurement process. This study concentrates on determining the $d$ -axis and $q$ -axis inductances of two different surface-mount PM motors at standstill and under running conditions. The standstill measurement methods evaluated include the “current decay” method and the “dc inductance bridge” method as well as more common methods. The dependence of the inductances on the current magnitude, frequency, and excitation signal waveform is investigated. Measurements with PWM and sinusoidal ac voltage excitation are found to give similar results. The tests indicated that the “current decay” method is prone to measurement errors especially when the phase resistance is low. It is discovered that inductance measurements from standstill tests are independent of frequency for all practical purposes. Next, the same inductances are measured, while the test motors are running. The methods considered include; inductance measurement from no-load test, zero power factor (PF) load test, and unity PF load test; while the machine is in generating mode. Furthermore, a new inductance measurement method is introduced where the measurement is made while the test motor is driven with a vector-controlled drive. Finally, inductance measurement results from different standstill tests and running tests are compared and evaluated.
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    Avoiding contingent incidents caused by a quadrotor due to one or two propellers failure
    (PLoS ONE, 2023-03-03) Altınuç, Kemal Orçun ; Khan, Muhammad Umer ; Iqbal, Jamshed
    With the increasing impact of drones in our daily lives, safety issues have become a primary concern. In this study, a novel supervisor-based active fault-tolerant (FT) control system is presented for a rotary-wing quadrotor to maintain its pose in 3D space upon losing one or two propellers. Our approach allows the quadrotor to make controlled movements about a primary axis attached to the body-fixed frame. A multi-loop cascaded control architecture is designed to ensure robustness, stability, reference tracking, and safe landing. The altitude control is performed using a proportional-integral-derivative (PID) controller, whereas linear-quadratic-integral (LQI) and model-predictive-control (MPC) have been investigated for reduced attitude control and their performance is compared based on absolute and mean-squared error. The simulation results affirm that the quadrotor remains in a stable region, successfully performs the reference tracking, and ensures a safe landing while counteracting the effects of propeller(s) failures.
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    Strawberries Maturity Level Detection Using Convolutional Neural Network (CNN) and Ensemble Method
    (Computer Vision and Machine Learning in Agriculture, 2023-08-01) Daşkın, Zeynep Dilan ; Khan, Muhammad Umer ; İrfanoğlu, Bülent ; Alam, Muhammad Shahab
    Harvesting high-quality products at an affordable expense has been the prime incentive for the agriculture industry. Automation and intelligent software technology is playing a pivotal role in achieving both practical and effective solutions. In this study, we developed a robust deep learning-based vision framework to detect and classify strawberries according to their maturity levels. Due to the unavailability of the relevant dataset, we built up a novel dataset comprising 900 strawberry images to evaluate the performance of existing convolutional neural network (CNN) models under complex background conditions. The overall dataset is categorized into three classes: mature, semi-mature, and immature. The existing classifiers evaluated during this study are AlexNet, GoogleNet, SqueezeNet, DenseNet, and VGG-16. To further improve the overall prediction accuracy, two Ensemble methods are proposed based on SqueezeNet, GoogleNet, and VGG-16. Based on the considered performance matrices, SqueezeNet is recommended as the most effective model among all the classifiers and networks for detecting and classifying the maturity levels of strawberries.
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    Performance assessment of tripping and drilling operations controllers on an experimental drilling rig prototype
    (Geoenergy Science and Engineering, 2023-07) Nobahar, Amir ; Arıkan, Kutluk Bilge ; Özbek, Mehmet Efe ; Naseri, Babek
    Oil well drilling towers have different operating modes during a real operation, each mode involves certain external disturbances and uncertainties. Performance evaluation of robust or adaptive Cascade PID, Active Disturbance Rejection, Loop Shaping, Feedback Error Learning, and Sliding Mode torque controllers, during the tripping and drilling operations, and their practical comparison are studied and evaluated by constructing a drilling rig prototype. The modeling of the experimental setup is extracted by mathematical modeling, and system identification. The practical performance of the controllers and their stabilities against the uncertain forces including the parametric uncertainties and the external disturbances are studied during the operations, by loading and unloading a disturbance weight. It has been shown that the effects of uncertain forces are successfully eliminated by the controllers. The Loop Shaping controller has the best performance among all the designed controllers, and all of them roughly consume the same control energy. A desired speed profile is designed to shape the vertical speed reference during the tripping operation, then its effect on the system behavior is analyzed to prevent the slackening problem in the drilling cable. Also, the behavior of control architectures in two modes of autonomous drilling is studied and analyzed. By analyzing and optimizing the performance efficiency in a controlled environment, along with enhancing the performances of the controllers, what we learn in this research could presumably be applicable in the field to have an accurate and safe operation.
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    Robotlar ve Mekatronik Mühendisliği
    (Bilim ve Teknoloji, 2012-07-22) ERDEN, Abdülkadir
    Robot kelimesi, ilk kez 1926 yılında kullanılmasına rağmen akademik olarak robot kavramını ilk öneren bilim ve mühendislik insanlarından biri 12. yy’da Selçuklu döneminde El-Cezeri’dir. Ünlü bilim adamı hizmetçilerin yerine iş yapan ve sultana hizmet eden otomat makinalar (robotlar) önermiş ve tasarlamıştır. Çağdaş bilim ve teknolojik gelişim süreci içinde ve 21. yy başında ulaşılan düzey itibarı ile robot kavramı, robot teknolojisi ve uygulamaları, insan ve toplum yaşamını değiştirecek, insan konforu (sağlık, barınma, gıda ve beslenme, eğitim, eğlence, seyahat vb.) ve güvenliği ile ilgili temel kavramlarda ve uygulamalarda köklü değişimlere yol açacak önemli bir bilimsel, mühendislik ve teknolojik aşama olarak yaşanmaktadır.