Magnetic Launcher Research Articles

Enhanced Area Defense: Magnetic Launcher and Sensor Integration

In this article, the most appropriate design method for a field defense system that operates with magnetic field laws by taking audio and video signals as reference is described. The study is important because it eliminates the operator (soldier) factor in the battlefield. Taking into account the effect of capacitor voltage, capacitance value and accelerator winding inductance value, the main criteria for determining the power supply and armature structure of the electromagnetic launcher are proposed. This proposal is made with MATLAB/Simulink software based mathematical model and the differences are explained by comparing with ANSYS Maxwell simulation. The simulated results show that the speed difference between the models is 7%. Additionally, the design methods of the audio and video-based positioning systems that control the system are explained in the study. In this system where signal receiving microphones are positioned in triangular form, a linear algorithm using the time difference method is utilized. By comparing the theoretical mathematical model with the experimental simulation model, the accuracy of the method and the method function is proved. In this study, a deep learning-based target detection system that operates with the YOLO v2 algorithm is used to increase the system's mission execution capacity. The operator is eliminated by switching the system with the signal received from the positioning systems.

Dynamics of Separation of Unmanned Aerial Vehicles from the Magnetic Launcher Cart during Takeoff

Most aircraft launchers exhibit a rapid acceleration of the launching aircraft, often exceeding ten times the acceleration due to gravity. However, only magnetic launchers offer flexible control over the propulsion force of the launcher cart, enabling precise control over the aircraft’s acceleration and speed during its movement on the launcher. Consequently, extensive research is being conducted on magnetic launchers to ensure the repeatability of launch parameters, protect against aircraft overloads, and ensure operator safety. This article describes the process of modeling and analyzing the dynamical properties of a launch cart of an innovative prototype launcher, which employs a passive magnetic suspension with high-temperature superconductors, developed under the GABRIEL project. The developed mathematical model of the magnetic catapult cart was employed to conduct numerical studies of the longitudinal and lateral movement of the cart, as well as the configuration of the UAV–cart system during UAV takeoff under variable atmospheric conditions. An essential aspect of the research involved experimentally determining the magnetic levitation force generated by the superconductors as a function of the gap. The results obtained demonstrate that the analyzed catapult design enables safe UAV takeoff. External factors and potential vibrations resulting from uneven mass distribution in the UAV–cart system are effectively balanced by the magnetic forces arising from the Meissner effect and the flux pinning phenomenon. The primary advantage of the magnetic levitation catapult, in comparison to commercial catapults, lies in its ability to provide a reduced and consistent acceleration throughout the entire takeoff process.

VR-Supported Analysis of UAV—Magnetic Launcher’s Cart System

The subject of the research is a model of a magnetic launcher, which is an innovative alternative to commercially occurring unmanned aircraft launchers (UAV). As the take-off is an energy-demanding phase of the flight; therefore, abandoning the power supply of the UAV during this phase significantly affects increasing the potential range and duration of UAV flight. The magnetic launcher offers the significant advantage of minimizing friction between the starting cart and the launcher, resulting in the higher energy efficiency of the system. Research conducted so far has shown that the possibility of accelerating the aircraft on the longer runway offered by the launcher reduces aircraft overloads occurring during take-off. As a result, the launcher, aircraft, and onboard equipment are much safer. This paper presents the system’s mathematical modeling and numerical simulation results for micro-class UAV take-off and landing using the analyzed magnetic launcher. The computer program for analyzing system dynamics was implemented in the MATLAB environment. Simulation results were visualized graphically and as animations in Virtual Reality. The VR application was implemented in Unity and ran on VR goggles Oculus Quest2. The simulations carried out show that—in the absence of control—an important factor reducing the takeoff distance and affecting the aircraft load is the adoption of a non-zero takeoff thrust of the UAV. The initial pitch angle also has a significant impact on the takeoff process. With an increase in this parameter, the length of the takeoff distance decreases and the lift-off speed decreases, but too much pitch angle may result in the aircraft descending in the first moments of flight, which could lead to a collision with the launch rails.

An Experimental Study on Sensorless Determination of the Projectile Position by Artificial Neural Network in Magnetic Launcher Systems

Electromagnetic launchers are systems in which energy is converted from one form to another. The energy applied to the launcher is converted into magnetic energy in the coil and then into motion energy. The object to be launched follows the magnetic field created in one or more fixed coils. The coil can be fed by direct current (dc) or alternative current (ac) source. In dc systems, the capacitor charging time delays the serial launch. In ac systems, the absence of capacitors enables serial launching. In this study, the application of an ac electromagnetic launch system, which provides a serial launch, is proposed. The maximum force acting on the projectile can be achieved by timely cutting off the energy applied to the coil. Therefore, in electromagnetic launchers, it is critical to know the position of the projectile in the coil. In launcher systems fed with alternating current, the projectile position can be predicted from current changes without the need for an additional setup. In the study, TMS320F28335 digital signal processor (DSP) microprocessor with high processing capacity was used to detect the trigger moment from coil current. Time-delayed artificial neural network was used to estimate the position of the projectile within the coil by using the obtained current differences. The normalized values of the current differences were applied to the time-delayed multilayer neural network (MLNN) algorithm and the projectile position was estimated with 94.67% accuracy. The proposed system increases efficiency compared to systems using conventional sensors, as it prevents or reduces the retraction force.

An autonomous switch based on a rotating magnet driven by magnetic launchers

This paper reports on an innovative electromagnetic energy harvester for autonomous switches relying on a rotating magnet driven by magnetic launchers, and combined with a ferromagnetic circuit and a coil to turn the variation of magnetic flux induced by the rotating magnet into electricity. The device is able to operate on forward and backward translation movements. The energy harvester has been modeled, optimized, manufactured, characterized and integrated into a mechanical actuation system to form a complete autonomous switch that will be commercially available. The experimental output energy reaches 1.235 mJ (350 µJ cm−3) which is among the highest output energies and energy densities reached on autonomous switches in the state of the art. The electromechanical conversion efficiency is 56%, which is excellent for an energy harvester, and obtained thanks to the topology chosen for the electromagnetic converter. The energy harvester is finally connected to a diode-bridge-capacitor circuit to supply the RF emission of the commands with a Zigbee Green Power® transmitter.

Design and Development of High Current Pulse Shaping Inductor Based on Bitter Magnet Configuration for Electro Magnetic Launcher

A unique pulse shaping inductor was designed and developed using a modified Bitter magnet configuration, to operate at peak current of 150 kA for duration of 5-10 ms in a Pulse Forming Network (PFN). The inductor was designed with a stack of parallel copper plates in the form of circular discs with a central hole, with GRP insulation plates in between. The design is optimized by electromagnetic finite element techniques for inductance and structural stability. The conducting discs and insulators are clamped together with tie rods between two endplates to provide adequate contact pressure and sufficient mechanical support. The conducting, inter connecting and insulating components were modeled and optimised parametrically for the desired performance and structural integrity. The device was fabricated, assembled and tested with 24 bitter plates for 28 μH inductance. The inductor was integrated with 400 kJ capacitor bank module and tested under static and dynamic condition. Current pulse of peak above 100 kA was generated, with consistent arc-free performance, high reliability and structural stability.

Solar photovoltaic source based magnetic launcher simulation design with thermal requirements consideration

Solar photovoltaic source based military defense systems, especially magnetic launchers, have significant advantages in terms of source independence, mobility, and efficiency. In this study, a solar photovoltaic sourced magnetic launcher system is modeled, and a critical component of the system’s (launcher coil) thermal requirements are analyzed. The designed system contains four energy conversion steps that are respectively photon, electrical, magnetic, and mechanical energy; also the launcher coil has an energy loss by the form of heat. Solar photovoltaic source based magnetic launcher system is sourced by solar photovoltaic panels and produced electrical energy is filtered, limited, and stored by an electrical converter. Stabilized electrical energy is converted to the magnetic energy by a coil. This magnetic energy is transferred to the projectile as mechanical energy. The microcontroller in the electrical converter unit controls all processes and manages the switching operations. Designed launcher coil is subject to a high amplitude current and employs simple, low-cost materials as an air core and copper wire. For this reason, the insulation breakdown on the launcher coil due to high temperatures are investigated, and a simple cooling configuration is suggested.

Towards implementation of a formation flying for efficient UAV operations

Abstract A flight of a UAV formation is an efficient way to implement surveillance and reconnaissance operations. The usage of a few UAVs as a formation instead of a single vehicle allows creating a distributed network of sensors, which decreases the duration of flight missions and enlarges a total field of view. From a practical point of view, implementations of formation flights require taking into account several separate aspects of flight of UAV such as a quick take-off of several aircraft, aggregating all UAVs in the same space to create swarm and collective flight of the formation towards the area of a surveillance mission. The paper presents the results of researches and experiments carried out towards practical solutions to those aspects. A magnetic launcher is an excellent appliance to put UAV in the air, and its operation could be repeated quickly. Hence, it is ideal to be used in a formation flight. The leader-follower approach based on two-stage switching control is an effective method to aggregate UAVs in the same space while they are flying over large areas. Whereas, the decentralized control of aerial flocking can be used to achieve a coherent flight of UAV formation, which is able to self-organize. Results from simulations and experiments show the effectiveness of each presented aspect and prove their usability in the implementation of formation flights.

Superconducting magnetic bearings simulation using an H-formulation finite element model

The modeling of superconducting magnetic bearings (SMBs) is of great significance for predicting and optimizing their levitation performance before construction. Although much effort has been made in this area, there still remains some space for improvements. Thus the goal of this work is to report a flexible, fast and trustworthy H-formulation finite element model. First the methodology for modeling and calibrating both bulk-type and stack-type SMBs is summarized. Then its effectiveness for simulating SMBs in 2D, 2D axisymmetric and 3D is evaluated by comparison with measurements. In particular, original solutions to overcome several obstacles are given: clarification of the calibration procedure for stack-type and bulk-type SMBs, details on the experimental protocol to obtain reproducible measurements, validation of the 2D model for a stack-type SMB modeling the tapes’ real thickness, implementation of a 2D axisymmetric SMB model, implementation of a 3D SMB model, and extensive validation of the models by comparison with experimental results for field cooling and zero field cooling, for both vertical and lateral movements. The accuracy of the model being having proven, it now has a strong potential for speeding up the development of numerous applications including maglev vehicles, magnetic launchers, flywheel energy storage systems, motor bearings and cosmic microwave background polarimeters.

Concept of the magnetic launcher for medium class unmanned aerial vehicles designed on the basis of numerical calculations

The paper presents a concept of a magnetic coil launcher for unmanned aerial vehicles of mass up to 25 kg. The idea is not new, nevertheless in the paper, an innovative application of magnetic launcher technology for selected class of unmanned aerial vehicles is presented. So far, at Bialystok University of Technology, a magnetic coil launcher for micro aerial vehicles of mass up to 2.5 kg has been investigated. In the article, simulations of a conceptual multi-coil launcher with a magnetic core system are presented. The finite element method has been used in calculations. Moreover, in the paper, the concept of a magnetic support for transmission of mechanical power from the magnetic core to the launched payload is proposed. The applied methodology, computational results and potential technical difficulties of practical applications are also widely discussed.

Simulation Model of an Electromagnetic Multi-Coil Launcher for Micro Aerial Vehicles

The paper presents a model of the 10-coil launcher, which can be used as a catapult of micro aerial vehicles (MAVs). The main advantage of such a device is the possibility of controlling its acceleration. We have also shortly described main disadvantages of pneumatic and rubber launchers and compared them to our solution which involved magnetic phenomena. The history and the classification of magnetic launchers were also mentioned. The investigated magnetic system was described in details. The system voltage equations and energetic conversions which take place during the launch were presented. With the use of finite element method we calculated the lumped parameters of the system (self-and mutual inductances). Nonlinear model was implemented in the MATLAB packet. Launch operation was divided into an acceleration and a braking phase. Thus, nine coils operated as accelerators and the last one was employed as a magnetic brake. The system was controlled by means of PID regulators which were tuned manually. Current values in the modelled coils were also limited by bang-bang controllers. In the last part of the paper we presented results of simulations and discussion about possible improvements of the model in the future.

Selection of Coils Parameters in Magnetic Launchers

This paper describes the process of a coil launcher parameters selection. Objective function Θ was defined and crucial variables were sought. The electro-mechanical system consisting of a copper coil and a ferromagnetic core was designed. Displacement of the core was computed. The magnetic force and coil inductance were calculated in many core position in relation to solenoid. Simulations were done by means of Finite Elements Method (FEM). The model parameters were being changed and the best system geometry was sought. In order to achieve better legibility, the research results were shown in the graphs. Selection process turned out to be very complex. In order to determine the best device parameters, the currents thermal effects should be taken into consideration. As the final conclusion some constructional conceptions of the magnetic launcher were proposed. The research will be continued to improve the coil launcher optimization process. The aim of future investigations is to achieve greater magnetic force and lower inductance of the electro-mechanical system.