scholarly journals Design of a 3-RPR Flexure System for Optical Switch Assembly

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Guiyue Kou ◽  
Mouyou Lin ◽  
Changbao Chu
Keyword(s):  
Permanent Magnets ◽  
Optical Switch ◽  
Low Cost ◽  
Mechanical Vibration ◽  
Analytical Models ◽  
Assembly System ◽  
Sensors And Actuators ◽  
Damping Force ◽  
Element Analysis ◽  
Compact Size

In the MEMS optical switch assembly, the collision is likely to happen between the optical fiber and the U-groove of the chip due to the uncontrollable assembly errors. However, these errors can hardly be completely eliminated by the active control using high precision sensors and actuators. It will cause the large acting force and part damage, which further leads to the assembly failure. To solve this question, this paper presents a novel low-cost three-degree-of-freedom (three-DOF) passive flexure system to adaptively eliminate the planar assembly errors. The flexure system adopts three parallel kinematic chains with a novel 3-RPR structure and has a compact size with a diameter of 125 mm and thickness of 12 mm. A novel eddy current damper with the structure of Halbach array permanent magnets (PMs) is utilized to suppress the adverse mechanical vibration of the assembly system from the background disturbances. Analytical models are established to analyze the kinematic, static, and dynamic performances of the system in detail. Finally, finite element analysis is adopted to verify the established models for optimum design. The flexure system can generate a large deformation of 1.02 mm along the two translational directions and 0.02° along the rotational direction below the yield state of the material, and it has much higher natural frequencies than 200 Hz. Moreover, the large damping force means that the designed ECD can suppress the system vibration quickly. The above results indicate the excellent characteristics of the assembly system that will be applied into the optical switch assembly.

scholarly journals A Combination of a Vibrational Electromagnetic Energy Harvester and a Giant Magnetoimpedance (GMI) Sensor

Sensors ◽  
2020 ◽  
Vol 20 (7) ◽  
pp. 1873
Author(s):  
Juan Jesús Beato-López ◽  
Isaac Royo-Silvestre ◽  
José María Algueta-Miguel ◽  
Cristina Gómez-Polo
Keyword(s):  
Permanent Magnets ◽  
Energy Harvester ◽  
Vibrational Energy ◽  
Magnetic Levitation ◽  
Low Cost ◽  
Mechanical Vibration ◽  
Inertial Mass ◽  
Amorphous Wire ◽  
Magnetic Element ◽  
Giant Magnetoimpedance

An energy harvesting device combined with a giant magnetoimpedance (GMI) sensor is presented to analyze low frequency vibrating systems. An electromagnetic harvester based on magnetic levitation is proposed for the electric power generation. The device is composed of two fixed permanent magnets at both ends of a cylindrical frame, a levitating magnet acting as inertial mass and a pick-up coil to collect the induced electromotive force. At the resonance frequency (10 Hz) a maximum electrical power of 1.4 mW at 0.5 g is generated. Moreover, an amorphous wire was employed as sensor nucleus for the design of a linear accelerometer prototype. The sensor is based on the GMI effect where the impedance changes occur as a consequence of the variations of the effective magnetic field due to an oscillating magnetic element. As a result of the magnet’s periodic motion, an amplitude modulated signal (AM) was obtained, its amplitude being proportional to mechanical vibration amplitude (or acceleration). The sensor’s response was examined for a simple ferrite magnet under vibration and compared with that obtained for the vibrational energy harvester. As a result of the small amplitudes of vibration, a linear sensor response was obtained that could be employed in the design of low cost and simple accelerometers.

Design and Fabrication of a Robotic Arm for Material Handling

2005 ◽  
Vol 2 (2) ◽  
pp. 61
Author(s):  
P Nageswara Rao ◽  
Anuar Ahmad ◽  
Abdul Rahman Omar ◽  
Muhammad Azmi Ayub
Keyword(s):  
Motion Control ◽  
Material Handling ◽  
Low Cost ◽  
Educational Institution ◽  
Ball Screw ◽  
Pneumatic Cylinder ◽  
Joint Movement ◽  
Sensors And Actuators ◽  
Element Analysis ◽  
Prismatic Joint

The commercial robots are expensive for use in the educational institutions. The operation of them will not leave room for experimentation, which is necessary in an educational institution. Further a large number of components that can be used for building a robot are readily available in the market. Hence this project has been taken up to allow us to build a working robot using as many of the off the shelf components to provide the necessary flexibility. This would make it a low cost robot with enough flexibility for the students to experiment the various functions of the robot.The mechanical component of the manipulator was built with three degrees of freedom, one revolute and two prismatic joints. This configuration is most common to be used as a material-handling device for machine tools. The revolute joint was achieved by making use of a pneumatic rotary table and one prismatic joint is realized by means of a pneumatic cylinder. The second prismatic joint in the Z-direction is achieved by the use of an AC servomotor with a ball screw and linear motion elements to provide for accurate positioning capability. The gripper had been designed for cylindrical components, since this robot was conceived as a material handling unit for a CNC turning center. All the necessary design calculations had been done and the finite element analysis was carried out for the main structure. The control system of the robot was one of the crucial elements. A PC is used as a controller. The motion control was carried out with the help of a motion control card DC2-PC100. It had the ability to control 2 servo and 2 stepper motors in addition to other digital and analogue controls. Several types of sensors and actuators were used for the robot to be fully automatic. The signal conditioning circuitry was designed in house for the interfacing between sensors, actuators and controllers. The control algorithm was developed with the necessary functioning to coordinate all the joint movement as well as gripper manipulation.

Shape Optimized Heliostats Using a Tailored Stiffness Approach

2013 ◽  
Vol 136 (2) ◽  
Author(s):  
Li Meng ◽  
Zheng You ◽  
A. F. M. Arif ◽  
Steven Dubowsky
Keyword(s):  
Low Cost ◽  
Spot Size ◽  
Substantial Improvement ◽  
Analytical Models ◽  
Element Analysis ◽  
Optical Efficiency ◽  
Honeycomb Sandwich ◽  
Stiffness Profile ◽  
Optical Ray Tracing ◽  
The Ideal

In central receiver systems, the ideal reflective shape of a heliostat is a section of a paraboloid that adapting with the sun's angle and the mirror's location in the field. Deviation from this shape leads to optical astigmatism that increases the spot size on the receiver aperture, which eventually causes higher energy loss and lower conversion efficiency. However, it is challenging to implement the ideal shape by conventional design and manufacturing methods. In this paper, a novel compliant heliostat design methodology is proposed. By tailoring the two dimensional stiffness profile of a square plate, the paraboloid shape can be formed by a simple, low-cost mechanism with concentrated moment loads on the corners of the plate. The static optimized shapes, which can be easily realized by adjusting the loads according to the locations during heliostat assembly on the site, are suggested as approximations of the ideal shapes. Analytical models were developed in detail for the methodology. Numerical analysis consists of finite element analysis, optical ray tracing, and optimization. The numerical results illustrate that the performance of the shape optimized heliostats using tailored stiffness approach is close to the ideal shapes, providing substantial improvement in optical efficiency and reduction in spot size comparing to the flat mirrors. Furthermore, experiments on a prototype heliostat mechanism with a honeycomb-sandwich panel were conducted to validate the effectiveness of this low-cost shaping approach.

Modeling Eddy-Current Damping Force in Magnetic Levitation Systems With Conductors

2017 ◽  
Author(s):  
Mohammad Khodabakhsh ◽  
Mehran Ebrahimian ◽  
Bogdan Epureanu
Keyword(s):  
Permanent Magnet ◽  
Eddy Current ◽  
Eddy Currents ◽  
Magnetic Levitation ◽  
Analytical Models ◽  
Damping Force ◽  
Element Analysis ◽  
Wide Range ◽  
Eddy Current Damping ◽  
Damping Effects

An analytical method is used to develop a model to calculate steady-state eddy-current damping effects in two configurations of magnetic levitation (maglev) systems. The eddy-current based force (eddy-current force) is used for high precision positioning of a levitated permanent magnet in maglev systems. In these systems, the motion of the levitated permanent magnet and changes of the coil’s currents, generate eddy current in the conductors. The proposed analytical model is used to calculate both effects. A conductive cylindrical shell around the levitated object is implemented as a new technique to generate eddy currents in maglev systems. The model is also employed to obtain eddy-current damping effects in a system with a conductive plate beneath the levitated object. The analytical models match results from high fidelity finite element analysis (FEA) with acceptable accuracy in a wide range of operations. Advantages of the two configurations are discussed.

scholarly journals Matrix and reinforcement materials for low-cost building isolators: an overview of results from experimental tests and numerical simulations

2019 ◽  
Vol 17 (1) ◽  
Author(s):  
Ingrid E. Madera Sierra ◽  
Johannio Marulanda Casas ◽  
Peter Thomson
Keyword(s):  
Low Cost ◽  
Experimental Tests ◽  
Steel Plates ◽  
Analytical Models ◽  
Compression Tests ◽  
Horizontal Shear ◽  
Scrap Tire ◽  
Element Analysis ◽  
Isolation System ◽  
Scrap Tire Rubber

During the last years several options to replace the conventional steel-reinforced isolators have been investigated using different materials for the matrix and reinforcement to implement isolation system in buildings. As alternatives to natural rubber, recycled elastomers derived from tires and industrial leftover, scrap tire rubber pads and nanocomposite rubber, have been proposed. Furthermore, with the goal of replacing the inflexible, thick steel plates, a wide variety of fabric reinforcements, such as nylon, carbon, polyester, polyamide, glass and thin flexible steel plates, have been investigated. The manufacturing process and connections between the devices and the structure (bonded, unbonded and partially bonded) have also been studied. This paper presents an overview of the results from investigations where the mechanical properties of prototypes were determined through horizontal shear and vertical compression tests and, in certain cases, through finite element analysis with hyperelastic models. In order to facilitate the visualization and comparison between investigations, the results are tabulated and plotted. The organization and presentation of the results allows to identify important aspects implemented in different experimental programs and analytical models developed for low-cost isolators.

Study and design of dual stator permanent magnet machine with spoke-type configurations using phase-group concentrated-coil windings

2020 ◽  
Vol 64 (1-4) ◽  
pp. 1381-1389
Author(s):  
Dezhi Chen ◽  
Chengwu Diao ◽  
Zhiyu Feng ◽  
Shichong Zhang ◽  
Wenliang Zhao
Keyword(s):  
Permanent Magnet ◽  
Permanent Magnets ◽  
Low Cost ◽  
Dynamic Performance ◽  
Torque Ripple ◽  
Permanent Magnet Machine ◽  
Torque Density ◽  
Phase Group ◽  
High Torque ◽  
Simulation Results

In this paper, a novel dual-stator permanent magnet machine (DsPmSynM) with low cost and high torque density is designed. The winding part of the DsPmSynM adopts phase-group concentrated-coil windings, and the permanent magnets are arranged by spoke-type. Firstly, the winding structure reduces the amount of copper at the end of the winding. Secondly, the electromagnetic torque ripple of DsPmSynM is suppressed by reducing the cogging torque. Furthermore, the dynamic performance of DsPmSynM is studied. Finally, the experimental results are compared with the simulation results.

scholarly journals Efficient Estimation of CFO-Affected OFDM BER Floor in Small Cells with Resource-Limited IoT End-Points

Sensors ◽  
2020 ◽  
Vol 20 (13) ◽  
pp. 3747
Author(s):  
Adriana Lipovac ◽  
Vlatko Lipovac ◽  
Borivoj Modlic
Keyword(s):  
Orthogonal Frequency Division Multiplexing ◽  
Carrier Frequency Offset ◽  
Signal To Noise Ratio ◽  
Low Cost ◽  
Error Recovery ◽  
Efficient Estimation ◽  
Analytical Models ◽  
Small Cells ◽  
End Points ◽  
Power Delay Profile

Contemporary wireless networks dramatically enhance data rates and latency to become a key enabler of massive communication among various low-cost devices of limited computational power, standardized by the Long-Term Evolution (LTE) downscaled derivations LTE-M or narrowband Internet of Things (NB IoT), in particular. Specifically, assessment of the physical-layer transmission performance is important for higher-layer protocols determining the extent of the potential error recovery escalation upwards the protocol stack. Thereby, it is needed that the end-points of low processing capacity most efficiently estimate the residual bit error rate (BER) solely determined by the main orthogonal frequency-division multiplexing (OFDM) impairment–carrier frequency offset (CFO), specifically in small cells, where the signal-to-noise ratio is large enough, as well as the OFDM symbol cyclic prefix, preventing inter-symbol interference. However, in contrast to earlier analytical models with computationally demanding estimation of BER from the phase deviation caused by CFO, in this paper, after identifying the optimal sample instant in a power delay profile, we abstract the CFO by equivalent time dispersion (i.e., by additional spreading of the power delay profile that would produce the same BER degradation as the CFO). The proposed BER estimation is verified by means of the industry-standard LTE software simulator.

scholarly journals A 300-GHz low-cost high-gain fully metallic Fabry–Perot cavity antenna for 6G terahertz wireless communications

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Basem Aqlan ◽  
Mohamed Himdi ◽  
Hamsakutty Vettikalladi ◽  
Laurent Le-Coq
Keyword(s):  
Communication Systems ◽  
Low Cost ◽  
Frequency Selective Surface ◽  
High Gain ◽  
Wireless Communication Systems ◽  
Beam Radiation ◽  
Compact Size ◽  
Fabry Perot ◽  
Operating Bandwidth ◽  
Polarization Level

AbstractA low-cost, compact, and high gain Fabry–Perot cavity (FPC) antenna which operates at 300 GHz is presented. The antenna is fabricated using laser-cutting brass technology. The proposed antenna consists of seven metallic layers; a ground layer, an integrated stepped horn element (three-layers), a coupling layer, a cavity layer, and an aperture-frequency selective surface (FSS) layer. The proposed aperture-FSS function acts as a partially reflective surface, contributing to a directive beam radiation. For verification, the proposed sub-terahertz (THz) FPC antenna prototype was developed, fabricated, and measured. The proposed antenna has a measured reflection coefficient below − 10 dB from 282 to 304 GHz with a bandwidth of 22 GHz. The maximum measured gain observed is 17.7 dBi at 289 GHz, and the gain is higher than 14.4 dBi from 285 to 310 GHz. The measured radiation pattern shows a highly directive pattern with a cross-polarization level below − 25 dB over the whole band in all cut planes, which confirms with the simulation results. The proposed antenna has a compact size, low fabrication cost, high gain, and wide operating bandwidth. The total height of the antenna is 1.24 $${\lambda }_{0}$$ λ 0 ($${\lambda }_{0}$$ λ 0 at the design frequency, 300 GHz) , with a size of 2.6 mm × 2.6 mm. The proposed sub-THz waveguide-fed FPC antenna is suitable for 6G wireless communication systems.

Analysis of a Tubular Linear Permanent Magnet Motor for Reciprocating Compressor Applications

2013 ◽  
Vol 448-453 ◽  
pp. 2114-2119 ◽  
Author(s):  
Izzeldin Idris Abdalla ◽  
Taib Ibrahim ◽  
Nursyarizal Mohd Nor
Keyword(s):  
Permanent Magnet ◽  
Permanent Magnets ◽  
Outer Radius ◽  
Design Parameters ◽  
Reciprocating Compressor ◽  
Permanent Magnet Motors ◽  
Permanent Magnet Motor ◽  
Element Analysis ◽  
Split Ratio ◽  
Single Coil

This paper describes a design optimization to achieve optimal performance of a two novel single-phase short-stroke tubular linear permanent magnet motors (TLPMMs) with rectangular and trapezoidal permanent magnets (PMs) structures. The motors equipped with a quasi-Halbach magnetized moving-magnet armature and slotted stator with a single-slot carrying a single coil. The motors have been developed for reciprocating compressor applications such as household refrigerators. It is observed that the TLPMM efficiency can be optimized with respect to the leading design parameters (dimensional ratios). Furthermore, the influence of mover back iron is investigated and the loss of the motor is computed. Finite element analysis (FEA) is employed for the optimization, and the optimal values of the ratio of the axial length of the radially magnetized magnets to the pole pitch as well as the ratio of the PMs outer radius-to-stator outer radius (split ratio), are identified.

Microactuator based on electroplated permanent magnets and flexible polydimethyl siloxane diaphragm

2008 ◽  
Vol 222 (3) ◽  
pp. 517-524 ◽  
Author(s):  
Y Su ◽  
H Wang ◽  
W Chen
Keyword(s):  
Permanent Magnets ◽  
Magnetic Energy ◽  
Optical Switch ◽  
Geometrical Parameters ◽  
Maximum Deflection ◽  
Polydimethyl Siloxane ◽  
Flexible Membrane ◽  
Microelectromechanical System ◽  
Planar Coil ◽  
A Current

The design, fabrication, and testing of a novel bidirectional magnetic microactuator were presented in the paper. The microactuator is composed of an integrated planar coil and a flexible polydimethyl siloxane (PDMS) diaphragm with embedded CoNiMnP-based permanent magnet arrays. There is a 7 × 7 array of magnets in a unit. The PDMS diaphragm is 2 mm × mm × 40 μm and the magnet post is 50 × 50 × 20 μm. Computer simulation was applied to verify the geometrical parameters. Electroplating under external magnetic field is carried out to improve the magnetic properties of the electroplated magnet, including coercivity, remanence and magnetic energy, and so on. The measured maximum coercivity, remanence and maximum magnetic energy were 2623 Oe (208.73 kA/m), 0.2 T (2000 G), and 10.15 kJ/m3 with the magnetic post, respectively. Moreover, and the deflection of the PDMS membrane is proportional to the exciting current. In a case of 0.35 A current, the maximum deflection of the membrane is 45 μm. Adjusting the electroplating mould results in the variation of the electroplated structure, thus the calibration of the microactuator. Due to the biomedical compatibility and simplicity of the fabrication, the flexible membrane-based microactuator is potential to be used as micropump and optical switch, the microelectromechanical system applications.

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