Due to the substantial increase in the number of electrically driven systems onboard more electric aircraft (MEA), the onboard electric power systems (EPSs) are becoming more and more complex. Therefore, there is a need to develop a control strategy to manage the overall EPS energy flow and ensure the operation of safety-critical systems (which are electrical loads) under different operating scenarios and to consider EPS losses minimization, exploiting the thermal capability of generators, different load priorities, and available batteries with their charging and discharging schedules. This article presents an energy management (EM) strategy that considers the aforementioned objectives. The optimal droop gain approach is employed as a power-sharing method to minimize the total EPS losses in MEA. A finite state machine (FSM) has been used to implement the control strategy to realize the EPS reconfiguration
This paper provides a design, a charging control, and energy management of a movable Photo Voltaic (PV) charging station with an Automatic Battery Replacement (ABR) system to enable drones for ongoing missions. The paper represents the first stage of a three-staged project titled Fall Armyworm (FAW) insect killer. The other two stages involve the flight control of drones and detecting and killing FAW insects. Without chemical methods, the project aims to eliminate harmful FAW insects that are rapidly spreading in Africa and Asia. The power source is a hybrid PV system with energy storage devices (batteries and supercapacitors). The maximum power from PV panels is tracked using three different online methods (PSO, IC, and P&O), and the best method with the highest accuracy is selected. The experimental and simulation results approved that PSO is the recommended method used in this project among the studied methods because of its high target reach (about 97%) and low steady-state oscillation (maximum 2.15%). An intelligent energy management system is investigated and designed to efficiently utilize solar power with a constant-current constantvoltage charger for LiPo batteries. A new Battery Selection System (BSS) is designed and verified to efficiently utilize the harvested energy and increase the mission time. The BSS targets to manage the selection of the appropriate battery to charge and control its charging rate. The system performance is tested using MATLAB software. Then, an experimental setup for the system is built to validate simulation results. The results of simulations and experiments proved the reliability of BSS
Finding the optimum path for mobile robots is now an essential task as lots of autonomous mobile robots are widely used in factories, hospitals, farms, etc. Many path planning algorithms have been developed to finding the optimum path with the minimum processing time. The vertical cell decomposition algorithm (VCD) is one of the popular path planning algorithms. It is able to find a path in a very short time. In this paper, we present a new algorithm, called the Radial cell decomposition (RCD) algorithm, which can generate shorter paths and a slightly faster than VCD algorithm. Furthermore, the VCD algorithm cannot be applied directly to obstacles in special cases, like two vertices have the same x-coordinate; on the other hand, the RCD algorithm can be applied to these special cases directly. In addition to that, the RCD algorithm is very suitable for corridor environments, unlike the VCD algorithm. In this paper …
Structure health monitoring is a general term used to describe the process of assessing the civil structure status and detecting and/or identifying any damage that occurs in the structure under monitoring. This work presents the design and operation of a synchronized structure health monitoring system that utilizes the internet of things technology. The proposed system consists of leaf nodes, a central node, and a monitoring server. The system utilizes two different wireless technologies to efficiently transfer the data and eliminate the need of fixed network infrastructure. The leaf nodes collect the acceleration signals from specific points in the structure using synchronized accelerometer sensors and send these signals to the central node using short range wireless communication protocol. The sampling process is synchronized among different sensors using an accurate timing signal from the global positioning system and an accurate external clock. The central node gathers the signals and relays them to a remote server using long range cellular internet connectivity. At the server, different damage detection and identification techniques are applied on the received data to assess the status of the structure. We provide details about the proposed system design and operation including the hardware and software parts. The different damage detection and identification techniques were considered and compared for predicting structural damage. Moreover, practical experiments were carried out, in which a five-story building model and real plane truss bridge were used to test the system. The results show the feasibility of the proposed synchronized system in automating the change in stiffness and mass by monitoring the dynamic behaviour.
Photovoltaic (PV) power systems are integrated with high penetration levels into the grid. This in turn encourages several modifications for grid codes to sustain grid stability and resilience. Recently, constant power management and regulation is a very common approach, which is used to limit the PV power production. Thus, this article proposes dual-mode power generation algorithm for grid-connected PV systems. The developed system considers the two-stage PV configuration for implementation, where the dual-mode power generation technique is executed within the DC–DC conversion (boost) stage. Most of the techniques adopted for dual-mode power operation employ the conventional perturb and observe method, which is known with unsatisfactory performance at fast-changing atmospheric conditions. Considering this issue, this study suggests a modified maximum power point tracker for power extraction. Furthermore, a new adaptive DC-link controller is developed to improve the DC-link voltage profile at different operating conditions. The adaptive DC-link controller is compared with the
traditional PI controller for voltage regulation. The inverter control is accomplished using finite-set model predictive control with two control objectives, namely reference current tracking and switching frequency minimization. The overall control methodology is evaluated at different atmospheric and operating conditions using MATLAB/Simulink software.
Sensorless strategies become very popular in modern control techniques because they increase the system reliability. Besides, they can be used as back-up control in case of sensor failure. In this paper, a DC-link sensorless control approach is developed, which is suited for grid-connected PV systems. The studied system is a two-stage PV scheme, where the DC–DC stage (boost converter) is controlled using an adaptive step-size perturb and observe (P&O) method. Further, the inverter control is accomplished by voltage oriented control (VOC). Generally, the VOC is implemented with two cascaded control loops, namely an outer voltage loop and an inner current loop. However, in this work, the outer loop is avoided and the reference current is generated using a losses model for the system. The losses model accounts for the most significant losses in the PV system. Moreover, particle swarm optimization (PSO) is utilized to compensate for the unmodeled losses. The PSO is
executed offline for the purpose of calculation burden reduction. The proposed approach simplifies the cascaded VOC strategy and eliminates the DC-link voltage sensor, which in turn decreases the cost of the system. Finally, the proposed technique is compared with the conventional one at different atmospheric conditions and validated using MATLAB simulation results.
Frictional stir welding (FSW) technology is increasingly used to weld various alloys, especially aluminum alloys, which are used in the manufacture of aircraft, ships, trains, etc. One of the most common techniques used to improve the mechanical properties of welded joints made of different alloy aluminum is the Vertical Compensation Friction Stir Welding (VCFSW) technique. Moreover, the use of different conditions of post-weld heat treatment of VCFSWed joints has a major impact on the mechanical properties of welded joints . Therefore, in the present work, different conditions of post-weld heat treatments were carried out on the VCFSW joints in order to improve the mechanical properties. Specifically, this paper focused on the effect of aging conditions (artificial aging at 120°C, 140°C, and 160°C) and 3 mm wide VCFSW static tape on mechanical properties such as fine hardness and tensile stress . Overall, the results indicated improvement in mechanical properties after using post-weld heat treatment. Specifically, the highest values of exact hardness and tensile strength were obtained at 140 °C, which is due to the change of the microstructure of the welded area by post-weld heat treatment conditions
he Brix value is an important factor in the sugar industry's extraction processes. Brix refers to the amount of sucrose in the raw sugar solution. The concentration of dissolved solids in a solution is measured by the degree Brix (symbol °Bx). One gram of sucrose in 100 grams of solution equals one-degree Brix. a New Suggested method for measuring brix was designed to be low-cost and accurate Brix measuring in raw sugar solutions. it was depended on Electronic sensors can directly measure the mass, and temperature of the solution to express the brix and give the result on the screen. Digital suggested brixmeter was made based on this method. It can be used manually on the production line and in various food industries. The aim of this paper was to evaluate the digital brixmeter performance for measuring brix in raw sugar solutions. Brix measurements were tested for a group of samples at different sizes to find the optimal measurement sizes can verify accurate brix degree value. The factors affecting the accuracy of the measurement were also studied. The results were compared with the brix read from accurate optical refractometer to check and a prove the accuracy of the proposed digital brixmeter.