Induction Magnetometers Principle, Modeling and Ways of Improvement

International audienceThis book provides an introductory overview of the research done in recent years in the area of magnetic sensors. The topics presented in this book range from fundamental theories and properties of magnets and their sensing applications in areas such as biomedicine, microelectromechanical systems, nano-satellites and pedestrian tracking. Written for the readers who wished to obtain a basic understanding of the research area as well as to explore other potential areas of applications for magnetic sensors, this book presents exciting developments in the field in a highly readable manner

Control and supervision of an AGV with energy consumption optimization

Os veículos guiados autónomos (AGVs) ganharam enorme importância e interesse no campo da indústria. Estes são soluções populares para o transporte de bens materiais para diferentes partes das fábricas. No entanto, em muitas fábricas, os armazéns estão localizados à parte da linha de produção ou em edifícios separados, exigindo que o transporte de bens materiais seja feito exteriormente. Os ambientes exteriores representam um desafio particular para os AGVs. Por um lado, estes ambientes causam mais desgaste nos componentes dos veículos e o clima na Europa pode atingir extremos opostos, dependendo da estação do ano e das regiões. Por outro lado, estes ambientes aumentam as preocupações de segurança, uma vez que outros veículos ou peões podem circular no mesmo espaço e ao mesmo tempo. Neste projecto, um rebocador eléctrico XXL será transformado num AGV, que opera em ambiente exterior. Este veículo é responsável pelo transporte de mercadorias do final da linha de produção para o armazém exterior numa fábrica de automóveis. O principal objectivo é assegurar o seu funcionamento contínuo durante um turno de 16 horas, garantindo o mínimo de interrupções para v«carregamento da bateria. Desta forma, nesta dissertação foram abordados dois capítulos distintos: para a análise e estudo do consumo energético foi simulado a powertrain de um veículo eléctrico. Neste, foi considerado um motor de indução cujo método de controlo aplicado foi o Field Oriented Control (FOC). Para além do comportamento eléctrico, também foi simulado o modelo físico da carga, bem como o cálculo da energia eléctrica consumida. Para a navegação, foi estudada uma solução baseada na integração do GPS com o INS. Dadas as restrições temporais, apenas a solução GPS foi testada e a técnica Loosely Coupled foi abordada como uma possível solução de integração.Autonomous guided vehicles (AGVs) have gained enormous importance and interest in the industry field. These are popular solutions for transport of good and material to different parts of the factories. However, in many factories, warehouses are located apart from the factory floor or in separate buildings, requiring the transport of material goods to be done outdoors. Outdoor environments represent a particular challenge for AGVs. On one hand, these environments causes more wear and tear on vehicle components and the weather in Europe can reach opposite extremes depending on the season and regions. On the other hand, these environments increase safety concerns since other vehicles or pedestrians can circulate in the same space at the same time. In this project, an electric tugger XXL will be transformed into an AGV, which operates in outdoor environment. This vehicle is responsible for transporting goods from the end of the production line to the outside warehouse in a car manufacturing plant. The main objective is to ensure its continuous operation during a 16-hour shift, and guarantee the minimum battery charging actions. In this way, in this dissertation two distinct chapters were approached: for the analysis and study of the energy consumption it was simulated the powertrain of an electric vehicle. In this one it was considered an induction motor whose control method applied was the Field Oriented Control (FOC). Besides the electrical behaviour, also the physical model of the load was simulated as well as the calculation of the consumed electrical energy. For navigation, a solution based on the integration of GPS with INS was studied. Given the temporal constraints, only the GPS solution was tested and the loosely coupled technique was approached as a possible integration solution

Measurement of permeability for ferrous metallic plates using a novel lift-off compensation technique on phase signature

Lift-off of sensor affects the prediction of electromagnetic properties for both ferrous and non-ferrous steel plates. In this paper, we developed a strategy to address this issue for ferrous plates. With increased lift-off, the phase of the measured impedance for steel plates reduces. Meanwhile, the magnitude of the impedance signal decreases. Based on these facts, a phase compensation algorithm is developed which corrects the phase change due to lift-off considering the magnitude of the impedance signal. Further, a new magnetic permeability prediction technique is presented, which has been validated by analytical and measured results. With this new technique, the error in permeability prediction is less than 2% within the range of lift-offs tested

Performance Comparison of Different Speed Estimation Techniques in Sensorless Vector Controlled Induction Motor Drives

Field-oriented control and direct torque control are fast becoming necessities of modern industrial setups for induction motor drive control. Induction motors are considered as the beginning part to create any electrical drive system to be subsequently utilized for several industrial requirements. So now a day due to its high application the need to control the performance of the induction motor is gaining importance. In modern control system, IM is analyzed by different mathematical models mainly depending on its applications. Vector control method is suitably applied to induction machine in 3-phase symmetrical or in 2-phase unsymmetrical version. For vector control IM is realized as DC motor having its characteristics. This dissertation work is aimed to give a detailed idea about the speed control and variations in an induction motor through vector control technique thereby showing its advantage over the conventional scalar method of speed control. It also focusses on the speed estimation techniques for sensorless closed loop speed control of an IM relying on the direct field-oriented control technique. The study is completed through simulations with use of MATLAB/Simulink block sets allowing overall representation of the whole control system arrangement of the Induction motor. The performance of different sensorless schemes and comparison between them on several parameters like at low speed, high speed etc. is also provided emphasizing its advantages and disadvantages. The analysis has been carried out on the results obtained by simulations, where secondary effects introduced by the hardware implementations have not been considered. The simulations and the evaluations of different control techniques are executed using parameters of a 50 HP, 60 Hz induction motor which is fed by an inverter

A Novel Variable Geometry based Planar Inductor Design for Wireless Charging Application

In this thesis, the performance, modelling and application of a planar electromagnetic coil are discussed. Due to the small size profiles and their non‐contact nature, planar coils are widely used due to their simple and basic design. The uncertain parameters have been identified and simulated using ANSYS that has been run utilising a newly developed MATLAB code. This code has made it possible to run thousands of trials without the need to manually input the various parameters for each run. This has facilitated the process of obtaining all the probable solutions within the defined range of properties. The optimum and robust design properties were then determined. The thesis discusses the experimentation and the finite element modelling (FEM) performed for developing the design of planar coils and used in wireless chargers. In addition, the thesis investigates the performance of various topologies of planar coils when they are used in wireless chargers. The ANSYS Maxwell FEM package has been used to analyse the models while varying the topologies of the coils. For this purpose, different models in FEM were constructed and then tested with topologies such as circular, square and hexagon coil configurations. The described methodology is considered as an effective way for obtaining maximum Power transfer efficiency (PTE) with a certain distance on planar coils with better performance. The explored designs studies are, namely: (1) Optimization of Planar Coil Using Multi-core, (2) planar coil with an Orthogonal Flux Guide, (3) Using the Variable Geometry in a Planar coil for an Optimised Performance by using the robust design method, (4) Design and Integration of Planar coil on wireless charger. In the first design study, the aim is to present the behaviour of a newly developed planar coil, built from a Mu-metal, via simulation. The structure consists of an excitation coil, sensing coils and three ferromagnetic cores 2 located on the top, middle and bottom sections of the coil in order to concentrate the field using the iterative optimisation technique. Magnetic materials have characteristics which allows them to influence the magnetic field in its environment. The second design study presents the optimal geometry and material selection for the planar with an Orthogonal Flux Guide. The study demonstrates the optimising of the materials and geometry of the coil that provides savings in terms of material usage as well as the employed electric current to produce an equivalent magnetic field. The third design study presents the variable geometry in a planar inductor to obtain the optimised performance. The study has provided the optimum and robust design parameters in terms of different topologies such as circular, square and hexagon coil configurations and then tested, Once the best topology is chosen based on performance. The originality of the work is evident through the randomisation of the parameters using the developed MATLAB code and the optimisation of the joint performance under defined conditions. Finally, the fourth design study presents the development of the planar coil applications. Three shapes of coils are designed and experimented to calculate the inductance and the maximum power transfer efficiency (PTW) over various spacing distances and frequency