Compact High Performance Research Articles

Thermal Analysis of a Novel Cylindrical Transverse-Flux Permanent-Magnet Linear Machine

This paper presents a novel staggered-teeth cylindrical transverse-flux permanent-magnet linear machine (TFPMLM), which aims to improve the power factor and force density. Due to the compact structure and high performance requirement, thermal problems should be seriously considered. The three-dimensional (3-D) temperature field model is established. The determination of convection heat transfer coefficients is discussed. Equivalent thermal conductivities of stator core and winding are given to simplify the analysis. With the thermal effect of the adhesive coatings among permanent magnets (PMs) and mover yoke taken into account, the temperature field distribution and variation rules of the TFPMLM are obtained using the finite volume method (FVM). The influences of slot filling factor and air flow velocity on the temperature field distribution are analyzed. It is found that the hottest spot of the TFPMLM appears in the middle of the end winding; and there is no risk of demagnetization for PMs.

Thermodynamic performance simulation and design optimisation of trilateral-cycle engines for waste heat recovery-to-power generation

Abstract The trilateral cycle (TLC) is one of the most promising alternatives among the heat recovery-to-power technologies, due to its compact system configuration and high performance at relatively low compression work and low-to-moderate expander inlet temperature. These feats make the TLC beneficial for off-grid applications particularly in remote or offshore applications where power-to-weight ratio of the power plant is of significance. This study presents the thermodynamic performance simulation and design optimisation of the TLCs using unconventional working fluid for heat recovery-to-power generation from low-grade waste heat, which is considered for process development and integration of the TLC. Four system configurations, comprising the simple TLC, recuperated TLC, reheat TLC and regenerative TLC are analysed and compared their performance metrics. Based on the theory of steady-state steady-flow thermodynamics, the simulation models of the TLC power plants, corresponding to their thermodynamic processes are established and implemented using engineering equation solver. The results show that the thermal efficiencies of the simple TLC, recuperated TLC, reheat TLC and regenerative TLC employing n-pentane are 11.85–21.97%, 12.32–23.91%, 11.86–22.07% and 12.01–22.9% respectively at subcritical operating conditions with low-grade heat in the temperature limit of 393–473 K. These suggest that the thermal integration of the optimised design of the simple TLC enhanced heat exchange efficiencies as well as the performance metrics. A comparative study among these cycles shows that the proposed recuperated TLC achieved the best performance metrics.

A Novel Dual-Band Mixer Using Arbitrary Impedances-Matching Coupler for Long-Term Evolution Applications

A novel microstrip dual-band down-conversion mixer is proposed in this article, which uses an inherent arbitrary impedances-matching coupler and a high-performance lowpass filter for long-term evolution (1.7–1.9 and 2.5–2.7 GHz) applications. Based on the accurate terminated impedances design method, the designed coupler can be directly used as an inherent matching network. In this article, the proposed dual-band mixer is fabricated and experimentally measured to show good agreement between simulated and measured results. This proposed mixer features a compact size and high linearity performance and achieves best power conversion gains of –15 and –10 dB in two bands, respectively. The input 1-dB compression point (P1dB) for two bands of the mixer are approximately –3 and –6 dBm, while the measured input third-order intercept point (IIP3) in two bands are 11 and 3 dBm, separately.

Machining robot for foamed polystyrene materials using fuzzy feed rate controller

Generally, cast metal is produced by using a sand mould. A foamed polystyrene mould is used as not only the master mould for making the corresponding sand mould but also the lost–foam pattern for full mould casting, i.e., lost–foam casting. Recently, the development of a flexible machining robot for foamed polystyrene materials is expected in the cast metal industries because of the high cost and inefficiency of conventional large sized CNC machine tools. In this paper, a machining robot based on an industrial robot is developed for foamed polystyrene materials by applying the already developed robotic CAM system. A compact and lightweight high performance tool is also considered and attached to the arm tip. The feed rate of an end mill is skilfully regulated by a fuzzy reasoning method. The design of the machining robot using the robotic CAM system and fuzzy feed rate controller is presented to efficiently produce foamed polystyrene moulds.

2C15 Dynamics and control of reconfigurable multi-body systems : Control utilizing embedded dynamic models in modules(The 12th International Conference on Motion and Vibration Control)

Mechanical systems have become more diverse and more complex. Control algorithms have been proposed for those systems by using compact sensors and high performance computers. As a result, the systems as well as the controller design processes have become more and more complex. Now, a simple method to design the control system is required. It is well known that modularization is effective for both hardware and software to design. Many reconfigurable modular robots have appeared so far. In those systems, however, the dynamics are not considered for motion control. Here we propose a new concept of modularization that integrates hardware modules and software modules in multi-body dynamic systems. Many mechanical systems are composed of multi-body systems. The mechanical system can be modularized with simple common elementary modules. To each module, a modularized simple dynamic model is given. A whole dynamic model can be constructed by connecting to each other dynamic model of each module. If the system is changed, its dynamic model can be constructed by changing the combination of elementary modules. In this study, our concept was evaluated by constructing software modules based on a Newton-Euler method as well as elementary hardware modules.

Real-time C++: efficient object-oriented and template microcontroller programming

The C++ language has powerful object-oriented and template features that can improve software design and portability while simultaneously reducing code complexity and the risk of error. Furthermore, C++ compiles highly efficient native code. This unique and effective combination makes C++ well-suited for programming microcontroller systems that require compact size, high performance and safety-critical reliability. With this book, Chris Kormanyos delivers a highly practical guide to programming real-time embedded microcontroller systems in C++. It is divided into three parts plus several appendices. Part I provides a foundation for real-time C++ by covering language technologies, including object-oriented methods, template programming and optimization. Next, part II presents detailed descriptions of a variety of C++ components that are widely used in microcontroller programming. It details some of C++s most powerful language elements, such as class types, templates and the STL, to develop components for microcontroller register access, low-level drivers, custom memory management, embedded containers, multitasking, etc. Finally, part III describes mathematical methods and generic utilities that can be employed to solve recurring problems in real-time C++. The appendices include a brief C++ language tutorial, information on the real-time C++ development environment and instructions for building GNU GCC cross-compilers and a microcontroller circuit. The most recent specification of C++11 in ISO/IEC 14882:2011 is used throughout the text. To facilitate portability, no libraries other than those specified in the language standard itself are used. Efficiency is always in focus and numerous examples are backed up with real-time performance measurements and size analyses that quantify the true costs of the code down to the very last byte and microsecond. The target audience of this book mainly consists of students and professionals interested in real-time C++. Readers should be familiar with C or another programming language and will benefit most if they have had some previous experience with microcontroller electronics and the performance and size issues prevalent in embedded systems programming.

Compact and high-performance bandpass filter and diplexer based on SCMRC-loaded SIR

Bandpass filter (BPF) and diplexer, which are required to be compact size and high performance, are widely used in modern wireless communication systems. In this article, novel BPF and diplexer are designed using the proposed resonator called spiral compact microstrip resonator cell (SCMRC)-loaded stepped-impedance resonator (SIR). The SCMRC-loaded SIR is proposed using the slow-wave structure SCMRC to replace the low-impedance section of the conventional SIR. Compared with the conventional SIR, the new SCMRC-loaded SIR has a compacter size and can generate a transmission zero above its fundamental resonant frequency. As examples, a BPF with the central frequency at f 0 = 1 GHz and a diplexer operating at 0.9/1.57 GHz are designed and fabricated. The fabricated BPF occupies a compact size of 0.07 λ 0 × 0.035 λ 0 and has a −60 dB rejection level wide stopband from 1.2 f 0 to 3.8 f 0. The fabricated diplexer occupies a compact size of 0.076 λ 0 × 0.128 λ 0 and has an up to −50 dB output isolation. Good agreement can be observed between the simulations and the measurements.

Rapid electrochemical detection on a mobile phone

We present a compact mobile phone platform for rapid, quantitative biomolecular detection. This system consists of an embedded circuit for signal processing and data analysis, and disposable microfluidic chips for fluidic handling and biosensing. Capillary flow is employed for sample loading, processing, and pumping to enhance operational portability and simplicity. Graphical step-by-step instructions displayed on the phone assists the operator through the detection process. After the completion of each measurement, the results are displayed on the screen for immediate assessment and the data is automatically saved to the phone's memory for future analysis and transmission. Validation of this device was carried out by detecting Plasmodium falciparum histidine-rich protein 2 (PfHRP2), an important biomarker for malaria, with a lower limit of detection of 16 ng mL(-1) in human serum. The simple detection process can be carried out with two loading steps and takes 15 min to complete each measurement. Due to its compact size and high performance, this device offers immense potential as a widely accessible, point-of-care diagnostic platform, especially in remote and rural areas. In addition to its impact on global healthcare, this technology is relevant to other important applications including food safety, environmental monitoring and biosecurity.

A newly developed rotary-linear motion platform with a giant magnetostrictive actuator

Demands for machining and measuring three-dimensional geometries have recently increased in a variety of industries. In order to meet such demands, it is necessary to develop a compact versatile high performance spindle system. This paper presents a newly developed rotary motion platform combined with a linear motion mechanism driven by a giant magnetostrictive actuator. The developed platform can be characterized by a compact structure, a noncontact structure, and high accuracy. Performance evaluation results confirm that the developed platform provides precise linear motion during rotating.

Research on the characteristics of tunable structure nanowire-grid polarizer

Nanowire-grid polarizer is of a periodic sub-wave structure of metallic nanowire on the substrate, fabricated by nanoimprint technology. Different from traditional polarization prism and dichroic polarizer, the nanowire-grid polarizer has many advantages such as compact size, easy integration and high polarization performance. However, in the ultraviolet and visible regions, it is infeasible to improve the performance of single layer nanowire structure by reducing the character size of nanowire because of the bottleneck of lithographic process. The double-layer nanowire-grid structure could improve the polarization characteristics at some special wavelengths but not full-wave band of ultraviolet and visible regions. In this paper, we propose a tunable double-layer structure to enhance the extinction ratio and transmission at each wavelength by tuning the distance between two nanowire-grid polarizers through adjusting the voltage applied to PZT. To calculate the transmittance and transmission extinction ratio of tunable structure, software VirtualLab is employed and the Fourier model method is used. The numerical simulation results show that the tunable structure have a higher polarization characteristic in ultraviolet and visible regions than single layer structure and double layers structure.

MIMO Exploitation of 3D Multipath Statistics in a Heterogeneous LTE-Advanced Network

This paper analyses the impact of 3D multipath in an LTE-Advanced heterogeneous network. The impact of the base station array configuration is considered in both the azimuth and elevation planes. Spatial and temporal multipath statistics are generated for example macro- and picocellular base stations, and these are combined with appropriately oriented complex polarimetric antenna patterns. The resulting wideband channels are then passed to an LTE-Advanced physical layer simulator. The optimal spatial multiplexing mode is determined by computing the throughput using the received bit mutual information rate for all modulation and coding schemes. The fastest link speed for each user is identified given a packet error rate threshold of 10%. Results show that RMS angle spread statistics and the base station MIMO array configuration strongly influence user performance in an LTE-A network. The deployment of macrocellular vertical arrays is shown to significantly degrade network performance. In contrast, the elevation angle spread is found to be far greater in picocells, and this allows vertical arrays to be applied to produce compact high performance picobase stations.

A Compact High-Performance Orthomode Transducer for the Atacama Large Millimeter Array (ALMA) Band 1 (31–45 GHz)

This paper describes a compact high-performance orthomode transducer (OMT) with a circular waveguide input and two rectangular waveguide outputs based on the superimposition of three aluminum blocks. Several prototypes operating in the band 1 (31-45 GHz) of the atacama large millimeter array have been fabricated and measured. The design is based on the use of a turnstile junction that is machined in a single block, requiring neither alignment nor a high degree of mechanical tolerances. Thus, a high repeatability of the design is possible for mass production. Across the 31-45 GHz band, the isolation is better than 50 dB and the return losses at the input and outputs of the OMT are better than -25 dB.

10 ps resolution, 160 ns full scale range and less than 1.5% differential non-linearity time-to-digital converter module for high performance timing measurements

We present a compact high performance time-to-digital converter (TDC) module that provides 10 ps timing resolution, 160 ns dynamic range and a differential non-linearity better than 1.5% LSB(rms). The TDC can be operated either as a general-purpose time-interval measurement device, when receiving external START and STOP pulses, or in photon-timing mode, when employing the on-chip SPAD (single photon avalanche diode) detector for detecting photons and time-tagging them. The instrument precision is 15 ps(rms) (i.e., 36 ps(FWHM)) and in photon timing mode it is still better than 70 ps(FWHM). The USB link to the remote PC allows the easy setting of measurement parameters, the fast download of acquired data, and their visualization and storing via an user-friendly software interface. The module proves to be the best candidate for a wide variety of applications such as: fluorescence lifetime imaging, time-of-flight ranging measurements, time-resolved positron emission tomography, single-molecule spectroscopy, fluorescence correlation spectroscopy, diffuse optical tomography, optical time-domain reflectometry, quantum optics, etc.

Industrial Spray Gun with Compact Dimensions and High Performance

Industrial Spray Gun with Compact Dimensions and High Performance

Through-Silicon-Via Design with Clustering Structure and Adaptive Through-Silicon-Via Control for Three-Dimentional Solid-State-Drive Boost Converter System

This paper presents a through-silicon-via (TSV) design methodology for three-dimentional solid-state-drive (3D-SSD) system with the 20 V boost converter. Although TSV technologies give compact packaging and high performance compared to the conventional wire-bonding technology, the parasitic resistors and capacitors of TSVs may cause the performance degradation. Additionally, since the number of the activated NAND chip is dynamically changed as access patterns from real processor, the optimum design point for the boost converter is also moved according to the situation. Then, the clustering method with two different sizes of Cu-TSVs and the adaptive TSV number controlling technique for polycrystalline silicon TSVs are proposed to reduce the parasitic resistors and capacitors. With the cluster structure and Cu-TSVs, the performance of the proposed 3D-SSD is improved by ∼10%. Furthermore, the adaptive TSV number controller enhances the performance up to 2 times higher for poly-Si TSV case by reducing the parasitic elements due to TSVs.

A triple band‐notched planar monopole antenna for ultrawide band applications

AbstractThis article presents the compact planar antenna with 3.5/5.5/8.2 GHz triple band‐notched characteristics. The antenna consists of an octagon shape patch with 50 Ω transmission line. By etching two C‐shaped slots in the patch and adding pair of L‐shaped resonator coupled to the radiating patch, band‐rejected filtering properties in the WiMAX/WLAN/ITU bands are achieved. The proposed ultrawide band (UWB) antenna is optimized to operate in the frequency band from 3 to 11 GHz for VSWR < 2. Measured results confirm that the antenna is suitable for UWB applications because of its compact size and high performance. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:539–543, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26581

ALLFlight: tackling the brownout problem

In 2008, the German Aerospace Center (DLR) started the project ALLFlight (Assisted Low Level Flight and Landing on Unprepared Landing Sites). The aim of the program is to integrate a full scale enhanced vision sensor suite in DLR’s research helicopter EC135. The sensor suite consists of a variety of imaging sensors, including a color TV camera and an uncooled thermal infrared camera. Two different ranging sensors are also part of the sensor suite: an optical radar scanner and a millimeter wave radar system. Both radar systems are equipped with specialized software for experimental modes, such as terrain mapping and ground scanning. To be able to process and display the enormous amount of data generated by these sensors, a compact high performance sensor co-computer system (SCC) has been designed and set up. It is built to be easily installable in the helicopter’s cargo bay. We describe the high performance, distributed data acquisition, recording, processing, and fusion software architecture that has been developed and implemented during the first project year. Furthermore, this paper describes the challenging mechanical integration of such a comprehensive sensor suite in the EC135 and explains the architectural hard- and software concept and its implementation in the SCC.

Special Issue on Pneumatics for Innovative Machine Design

Pneumatics has greatly progressed as convenient multifunctional automation technology. One typical application is in compact light-weight highperformance pneumatic actuators. The introduction of control theory has also enabled useful pneumatic servosystems. New actuators include pneumatic artificial rubber muscles, which are small, light-weight, and soft. These are used for applications in the medical, welfare, and nursing fields. This special issue focuses on actuator development in drive-circuit analysis and design. Issues in these areas include pneumatic actuators, pneumatic rubber muscles, pneumatic circuit analysis and design, energy-saving, pneumatic servocontrol, advanced control systems, industrial applications, automation, vehicles, entertainment, medical, welfare and nursing applications, and education. This special 13-article issue is divided into (i) control design and pneumatic cylinder and bellows applications and (ii) the development and applications of soft pneumatic actuators. Some types of soft pneumatic actuators use artificial rubber muscles for welfare and rehabilitation equipment. This special issue should prove useful in understanding state-of-the-art of pneumatic technology applicable to analysis, design, control, and application in innovative machine design. I would like to express my sincere appreciation to all of the authors and reviewers for their invaluable effort.

Hybrid Dielectric-Loaded Plasmonic Waveguide-Based Power Splitter and Ring Resonator: Compact Size and High Optical Performance for Nanophotonic Circuits

The key challenge of the plasmonic waveguide is to achieve simultaneously both the long propagation length and high confinement. The hybrid dielectric-loaded plasmonic waveguide consists of a SiO2 stripe sandwiched between a Si-nanowire and a silver film and thus promises as a best candidate to overcome this challenge. We propose to exploit this unique property of this structure to design different high-efficient silicon-based plasmonic components including waveguide, power splitter, and wavelength-selective ring resonator. As a result, the proposed power splitter with a waveguide cross section (λ 2/60) and a strong mode confinement area (~λ 2/240) features a low power transmission loss (<0.4 dB) at the optimal arm length of 4 μm with respect to different separation distances of output arms. Moreover, we also demonstrate that a plasmonic ring resonator with a compact ring radius of 2 μm may achieve high optical performance such as high-extinction ratio of 30 dB, large free spectral range of 67 nm, and small bandwidth of 0.6 nm. These superior performances make them promising building blocks for integrated nanophotonic circuits.

Investigations on hydrodynamics of multilayer Π‐type radial flow reactors

ABSTRACTConsisting of two or three different layers of catalyst or adsorbent, the multilayer radial flow reactor is a novel radial reactor with compact structure and high performance. In this article, pressure profiles in the flow channels and layers of a three‐layer radial flow reactor were measured and the properties of the fluids in the flow channels and layers were investigated. Results show that the uniformity of the pressure profiles in the distributing and collecting channels in the axial direction has a significant effect on the flow distribution of each layer. The uniformity of the flow distribution in multilayer Π‐type radial flow reactors varies in the radial direction. It is better in the outer layer than in the inner layer when the pressure variation in the center channel is more significant than that in the annular channel. The main contributions of this work are helpful to the proper design and optimum operation of the multilayer radial reactor. Copyright © 2011 Curtin University of Technology and John Wiley &amp; Sons, Ltd.