Optimal tuning of controller parameters for a magnetic levitation system using radial basis based neural network metamodeling approach

The Magnetic Levitation System (MLS) is a challenging nonlinear mechatronic system in which an electromagnetic force required to suspend an object (metal sphere) in the air. The electromagnetic force is very sensitive to the noise, which can create acceleration forces on the metal sphere, causing the sphere to move into the unbalanced region. Maglev’s benefits the industry, and the system has reduced power consumption, has increased power efficiency, and reduced maintenance cost. The typical applications for Maglev’s Power Generation, for example, wind turbine, Maglev’s trains, and Medical Device (magnetically suspended Artificial Heart Pump). This project presents a comparative assessment of controllers for the magnetic levitation system and the way of optimally tune of the PID parameter. The magnetic levitation system divided into two types, attractive and repulsive, in this project attractive type has been chosen. The analysis will be performed after finding the state space model of magnetic levitation system, and simulation will be performed using MATLAB Simulink. The optimal tuning based PID controller will offer a transient response with better overshoot and rise time than the standard optimization methods. For the trained networks, metamodel radial basis function networks perform more robustly and tolerantly than the gradient descent method even when dealing with noised input data set. The simulation output using the radial basis based metamodel approach showed an overshoot of 9.34% and rise time 9.84ms, which is better than the gradient descent and conventional PID methods

Controlling the properties of OPEFBPLA polymer composite by using fe2o3 for microwave applications

Microwave-absorptive polymer composite materials provide protection against interference to communication systems caused by microwave-inducing devices. Microwave-absorptive polymer composites were prepared from polylactic acid (PLA) biocomposite blended with oil palm empty fruit bunch (OPEFB) fiber and commercial Iron oxide (Fe2O3) as filler using the melt-blending method. The composites characterization was carried out using the scanning electron microscopy (SEM) and X-ray diffraction (XRD) analyses. The coefficient of reflection S11 and coefficient of transmission S21 of the composites for various Fe2O3 filler percentages were determined using a rectangular waveguide in connection with microwave vector network analyser (HP/Agilent model PNA N5227). These coefficients were then used to calculate microwave-absorption properties (in decibels). XRD analysis showed that increasing amounts of reinforced material (Fe2O3) reduces the crystallinity of the composites. SEM data indicated that Fe2O3 filler ratio increased in the composites, and adhesion to the cellulose fiber grew gradually until the highest percentage of filler was added. The complex relative permittivity and relative permeability were obtained within the broad frequency range of 8-12 GHz at room temperature for various percentages of filler and were measured by the transmission/reflection method using a vector network analyser. Fe2O3 embedment in OPEFB/PLA was observed to have resulted in enhancing the dielectric and magnetic properties. The values of permittivity and permeability increased with increasing Fe2O3 filler content. Theoretical simulation studied the relation between ε' and ε" of the relative complex permittivity in terms of Cole-Cole dispersion law. The result indicated that the processes of Debye relaxation in Fe2O3/OPEFB/PLA, the unique dielectric characteristics of Fe2O3 cannot be accounted for by both the Debye dipolar relaxation and natural resonance. Results further showed that the material transmission, reflection, and absorption properties could be controlled by changing the percentage of Fe2O3 filler in the composite

Controlling the properties of OPEFB/PLA polymer composite by using Fe2O3 for microwave applications

Microwave-absorptive polymer composite materials provide protection against interference to communication systems caused by microwave-inducing devices. Microwave-absorptive polymer composites were prepared from polylactic acid (PLA) biocomposite blended with oil palm empty fruit bunch (OPEFB) fiber and commercial Iron oxide (Fe2O3) as filler using the melt-blending method. The composites characterization was carried out using the scanning electron microscopy (SEM) and X-ray diffraction (XRD) analyses. The coefficient of reflection S11 and coefficient of transmission S21 of the composites for various Fe2O3 filler percentages were determined using a rectangular waveguide in connection with microwave vector network analyser (HP/Agilent model PNA N5227). These coefficients were then used to calculate microwave-absorption properties (in decibels). XRD analysis showed that increasing amounts of reinforced material (Fe2O3) reduces the crystallinity of the composites. SEM data indicated that Fe2O3 filler ratio increased in the composites, and adhesion to the cellulose fiber grew gradually until the highest percentage of filler was added. The complex relative permittivity and relative permeability were obtained within the broad frequency range of 8–12 GHz at room temperature for various percentages of filler and were measured by the transmission/reflection method using a vector network analyser. Fe2O3 embedment in OPEFB/PLA was observed to have resulted in enhancing the dielectric and magnetic properties. The values of permittivity and permeability increased with increasing Fe2O3 filler content. Theoretical simulation studied the relation between ε′ and ε″ of the relative complex permittivity in terms of Cole-Cole dispersion law. The result indicated that the processes of Debye relaxation in Fe2O3/OPEFB/PLA, the unique dielectric characteristics of Fe2O3 cannot be accounted for by both the Debye dipolar relaxation and natural resonance. Results further showed that the material transmission, reflection, and absorption properties could be controlled by changing the percentage of Fe2O3 filler in the composites

Fabrication and characteristics of oil palm fibre- reinforced polylactic acid composite filled with iron oxide for microwave application

Microwave absorbers generally consist of a filler material inside a polymer matrix. The filler contains one or more elements that do most of the absorbing. Absorbers are used in a wide range of applications to eliminate stray or unwanted radiation that could interfere with a system’s operation. Ferrites is the most common shielding material in the development of absorbing composites. However, ferrites are heavy, corrosive, non-biodegradable and expensive. This project investigates the application of oil palm empty fruit bunch fibres (OPEFB) as an alternative to ferrite fillers for microwave absorbing applications with PLA as the host matrix. OPEFB offer various advantages such as low cost, low density, better thermal, insulating properties and biodegradability. Also PLA has significant advantages including ease of fabrication, zero toxicity, biodegradability, high mechanical strength and thermal plasticity. Different compositions of filler were doped and blended to produce OPEFB-PLA and OPEFB-PLA-Fe2O3 composites via Brabender Plastograph EC blending machine operating at 170°C with rotor speed of 50 rpm for 20 minutes. The total mass of each blended composite was 45g and contained 200 μm size OPEFB fibres. The crystalline structure of the composites was analyzed using X-ray diffraction (XRD) machine. The elemental compositions were examined using Scanning Electron Microscopy (SEM), energy dispersive X-ray analysis (EDX) and Fourier transform infrared (FTIR) techniques. Thermal analyses were carried out using TGA and DTG. The dielectric properties and S-Parameters, were measured using a PNA (N5227) Network Analyzer from 8GHz to 12 GHz for rectangular waveguide and 0.01 GHz to 12 GHz for microstrip at room temperature. The theoretical calculations of the S-Parameters coefficients of the samples were computed using Finite Element Method (FEM) in conjunction with the COMSOL software. The comparison between the measured and calculated scattering parameters was also investigated. The permittivity of the composites was found to be dependent on the mixing ratio between OPEFB, PLA, and Fe2O3. At 10 GHz in the X-band frequencies, the dielectric constants of OPEFB-PLA and OPEFB-PLA-Fe2O3 composites were found to be between 3.04 to 3.36 and 3.14 to 3.7 respectively while the loss factor values were from 0.3 to 0.4 and 0.3 to 0. 346. Both the dielectric constant and loss factor of the OPEFB-PLA OPEFB-PLA-Fe2O3 composites increased with increasing percentages of OPEFB and Fe2O3 fillers. Furthermore, the results obtained from the scattering parameters |S11| and |S21| were used to determine the absorption loss of the different percentages of OPEFB-PLA and OPEFB-PLA-Fe2O3 composites samples, the absorption loss were found at 10 GHz to be from 0.049 to 0.105 and 0.045 to 0.062 respectively. Finally, the effect of the different percentages of OPEFB and Fe2O3 filler on the electric field was investigated by visualizing the electric field distribution pattern of the OPEFB-PLA and OPEFBPLA-Fe2O3 composites samples placed in the rectangular waveguide and placed on the top of microstrip using finite element method