This article is focused main problem during and after FSW especially when joining blanks AA2024 embedded with interlayer strip widths AA7075, in microstructure of the welded zone, that will in turn affect its mechanical properties of the welded joints. So, a number of interlock strip widths of AA7075 as 1, 1.5, 2, 2.5 and 3 mm were added between two substrates of base metal AA2024 during FSW technique then followed heating and cooling procedures to incorporate into the heat treatment process, which is conducted to create changes in a material's microstructure that will in turn affect its mechanical properties. The analyses by optical microscope and scanning electron microscope were used to clarify microstructural characterization of FSWed with interlock strip widths after PWHTed. On the other hand, the microhardness and tensile tests were performed to determine mechanical properties of FSWed with interlock strip widths after PWHTed. The observations of microstructural elucidated that the good bonding connection between interlayer strip widths AA7075 and base metal AA2024 was due to use the procedures of PWHT. The mechanical properties such as microhardness and tensile of produced joints with PWHTed were showed higher than without PWHTed. Specifically, the ultimate tensile strength, and hardness values of the post-heat joint when using 3mm interlayer strip were obtained the highest values 299MPa, 186 HV respectively. This presents improvement by 11.2% in tensile strength, and 84% in hardness, compared to as weld joint.

Water management, distribution, and consumption are not visualized in real time in conventional systems; this delays the leakage detection process. Nowadays, an increase in the development of smart water- meter trials and demand management requires higher spatial and temporal decisions. This paper proposes a solution for the water management and distribution problem. The solution is based on the IoT technology. First, a prototype abstracting the water distribution network (WDN) is developed. Second, sensors are installed on the network to capture the targeted physical quantities such as water pH level, turbidity, and flow rates. Third, sensor network is established to send the readings to Firebase platform. Fourth, an IoT testbed architecture is proposed to comprehensively interface all the IoT modules. Leakage detection scenarios are conducted to sense and warn admins and users to fix it. Application of the proposed system to smart homes would enable monitoring of water quality, measurement of consumption, and detection of leakage. Moreover, it provides an awareness highlight to users about consumption, and a monitoring platform for both users and admins for leakage detection.

Abstract—Implementation of robotic systems has significantly improved the flexibility and accuracy of prostate brachytherapy. In our previous study, an ultrasound (US) guided dual-arm robotic brachytherapy system was developed. This system was integrated with an end-effector for needle insertion and an end-effector for US probe. The calibration accuracy of the system determines the effectiveness of the whole system. However, existing calibration methods are mechanism-based calibration methods or image-based calibration methods. With these methods, external tracker and complex phantom are needed, which may result in accumulative errors. Therefore, this article presents a mechanism-image fusion approach to the calibration of a US-guided dual-arm robotic brachytherapy system. With this approach, no tracker or complex phantom is needed as the dual-arm robotic system can use one arm as a substitute for the tracker and phantom to calibrate the other arm. The needle-tip positions localized by the mechanism and image are utilized while the needle is also the controlled object of needle insertion. Experiments using three registration algorithms were performed, and results were evaluated utilizing the leave-one-out cross-validation method. The results showed that the calibration accuracy of the whole system is 0.65±0.31 mm. Additional experimental and parametrical comparisons of the proposed

This article presents a multiple-vector finite-control-set model predictive control (MV-FCS-MPC) scheme with fuzzy logic for permanent-magnet synchronous motors (PMSMs) used in electric drive systems. The proposed technique is based on discrete space vector modulation (DSVM). The converter’s real voltage vectors are utilized along with new virtual voltage vectors to form switching sequences for each sampling period in order to improve the steady-state performance. Furthermore, to obtain the reference voltage vector (VV) directly from the reference current and to reduce the calculation load of the proposed MV-FCS-MPC technique, a deadbeat function (DB) is added. Subsequently, the best real or virtual voltage vector to be applied in the next sampling instant is selected based on a certain cost function. Moreover, a fuzzy logic controller is employed in the outer loop for controlling the speed of the rotor. Accordingly, the dynamic response of the speed is improved and the difficulty of the proportional-integral (PI) controller tuning is avoided. The response of the suggested technique is verified by simulation results and compared with that of the conventional FCS-MPC.

In this article, a deadbeat predictive control (DB-PC) strategy for permanent-magnet synchronous generators (PMSGs)-based modern wind turbines is proposed. The main advantages of the DB-PC technique are its excellent dynamics and its constant switching frequency. However, the main idea of DB-PC is obtaining the actuation voltage for the next sample from the mathematical model of the generator. Therefore, the DB-PC is highly sensitive to mismatches in the parameters of the PMSG. In order to obviate this problem, a disturbance estimator (extended Kalman filter (EKF)) is employed in this work to enhance the robustness of the proposed DB-PC scheme by estimating the total disturbance due to parameter mismatches and adding it to the calculation of the actuation voltage. Furthermore, the same EKF observe the rotor speed and position of the PMSG, i.e., mechanical sensors are not required. Moreover, the EKF is able to reduce the harmonic distortion in the stator currents of the PMSG. The proposed DB-PC strategy is implemented in the laboratory. The experimental results proved the superiority of the proposed DB-PC strategy over the traditional DB-PC technique.

Maximum power point tracking (MPPT) is an essential and primary objective in photovoltaic (PV) systems implementation. Thus, in this article, the predictive fixed switching MPPT technique is proposed for a two-stage PV system, where the system under consideration consists of a PV source, boost converter, and two-level inverter. The MPPT design is based on dual adaptive step-size realization to limit the duty cycle oscillations at a steady state. Furthermore, the PI controller is eliminated, which simplifies the MPPT implementation. The suggested tuning procedure of the duty cycle is compared with the conventional adaptive step-size perturb and observe (P&O) method. The inverter is controlled using an efficient finite-set model predictive control (FS-MPC) algorithm with reduced computation burden, where the optimal switching state vector is identified based on the polarity of the reference voltage in the α - β reference frame and without any need for sector determination. Furthermore, the cost function of the FS-MPC algorithm is modified to include the reduction of the switching frequency as a secondary objective for the inverter control. The overall control methodology is evaluated using experimental results at different operating conditions.

The present paper deals with an active fault-tolerant speed tracking of a five-phase permanent magnet synchronous motor with currents and speed sensor failures. The active fault tolerant control scheme, integrating a sliding mode observer and backstepping controllers, is proposed to provide a continuous drive operation of the five-phase permanent magnet synchronous motor, even during more than one sensor fault occurrence. The sliding mode observer is designed to generate the residual signal necessary for the detection stage, whereas speed and current backstepping controllers handle the operation of the five-phase permanent magnet synchronous motor thanks to their ability to consider the nonlinearities of the system model in generating a control law that is robust enough in healthy and faulty cases. Furthermore, the FTC strategy uses the information received from the fault-tolerant switching block in terms of the measured and the observed currents and speed signals. To gain the maximum benefit of the sliding mode observer’s robustness to random noises and its ease of implementation, the observed currents and speed of the five-phase permanent magnet synchronous motor have been estimated. The simulation results are conducted to show the effectiveness of the proposed FTC control scheme and to prove its high performance in fault detection and tolerant control for the five-phase permanent magnet synchronous motor, since it significantly outperforms the performance provided by traditional methods.

In photovoltaic systems, parasitic capacitance is often formed between PV panels and the ground. Because of the switching nature of PV converters, a high-frequency voltage is usually generated over these parasitic capacitances; this, in turn, can result in a common-mode current known as leakage current. This current can badly reach a high value if a resonance circuit is excited through the PV’s parasitic capacitance and the converter’s inductive components. Transformers are usually used for leakage current mitigation. However, this decreases the efficiency and increases the cost, size, and weight of the PV systems. Number of strategies have been introduced to mitigate the leakage current in transformer-less converters. Among these strategies, using common-ground converters is considered the most effective solution as it offers a solid connection between the negative terminal of PV modules and the neutral of the grid side; thus, complete mitigation of the leakage current is achieved. Number of common-ground inverters have been recently presented. These inverters are different in their size, cost, boosting capability, the possibility of producing DC currents, and their capability to offer multilevel shaping of output voltage. This work introduces a comprehensive review and classification for various common-ground PV inverters. Therefore, a clear picture of the advantages and disadvantages of these inverters is clarified. This provides a useful indication for a trade-off between gaining some of the advantages and losing others in PV systems. In addition, the potentials for optimization based on different performance indicators are identified.