A mechatronic positioning system actuated using a micro DC-motor-driven propeller–thruster

One of the greatest challenges facing designers in the mechatronics field is the development of autonomous systems capable of guiding an airborne object along a given trajectory or maintaining its position in a specified location. Nonetheless, developing such ability is essential to support emerging UAV (Unmanned Aerial Vehicle) requirements in the civil and military domains. Accordingly, this study commences by constructing a mechatronic system featuring a manipulator arm actuated by a DC-motor-driven constant-pitch propeller and then develops suitable control schemes to regulate the power supplied to the DC motor such that the manipulator arm is driven through a specified rotational displacement. Three different control schemes are implemented to regulate the displacement of the manipulator arm, namely a fixed gain PID controller, a function-based variable gain PID controller and a fuzzy gain-mixing PID controller. The feasibility of the three control systems is evaluated both numerically and experimentally. It is shown that the fixed gain PID controller results in a significant overshoot of the manipulator arm and leads to a loss of control. However, the function-based variable gain PID controller and the fuzzy gain-mixing PID controller both ensure an accurate tracking performance, even when the manipulator arm is manually perturbed during rotation.     

面向越野自主导航的鲁棒GPS/INS融合定位系统

实时可靠的三维定位能力是自主车实现越野自主导航的前提.提出了一种基于全状态空间扩展卡尔曼滤波的GPS/INS融合算法.在考虑传感器误差源的基础上建立了系统观测方程.以连续状态空间为基础并加以离散化后建立了系统状态方程.最后由扩展卡尔曼滤波器实现了系统状态的可靠估计.该算法可以放松以往对INS误差精确建模的要求,并能有效地应对由路面剧烈颠簸导致的INS短时失效和由遮挡等原因导致的GPS失效.实验结果表明该GPS/INS融合定位系统是可靠和成功的.     

A new positioning system using television synchronization signals

The technique discussed herein may be used to position a range of wireless devices that require location information when in inclement urban conditions, including PDA's, laptops, cellular phones, asset-tracking devices and radios for emergency response personnel. We make use of synchronization signals that are part of the standard for Television set forth by the Advanced Television Systems Committee. Consequently, the technique described herein requires no changes to the television broadcast stations. The signal can accommodate robust indoor positioning where the Global Positioning System (GPS) fails, since the television synchronization signals typically have a power advantage over GPS of more than 40 dB. In addition, the effects of multipath are substantially mitigated since the signals have a bandwidth of roughly 6 MHz, and substantially superior geometry for triangulating lateral position to that which GPS can typically provide in inclement environments. A wide range of VHF and UHF frequencies have been allocated to television stations; consequently, there is redundancy built into the system to protect against deep fades on particular channels. In addition, unlike GPS, the synch signals are not affected by transmitter Doppler, ionospheric propagation delays, or data that is modulated onto the signals. In overview, the technology exploits the considerable Digital TV infrastructure to achieve more reliable, accurate and rapid positioning than can be achieved with existing technologies.     

A Millimeter-Wave (23–32 GHz) Wideband BiCMOS Low-Noise Amplifier

This paper presents a 23–32 GHz wideband BiCMOS low-noise amplifier (LNA). The LNA utilizes coupled-resonators to provide a wideband load. To our knowledge, the proposed LNA achieves the widest bandwidth with minimum power consumption using 0.18 $mu$m BiCMOS technology in K-band. Analytical expressions for the wideband input matching, gain, noise figure and linearity are presented. The LNA is implemented using 0.18 $mu$m BiCMOS technology and occupies an area of 0.25 mm$^2$ . It achieves a voltage gain of 12 dB, 3-dB bandwidth of 9 GHz, noise figure between 4.5–6.3 dB, linearity higher than ${-}$6.4 dBm with a power consumption of 13 mW from a 1.5 V supply.      

Intelligent ship autopilots––A historical perspective

The paper presents a historical perspective of the development and use of the so-called intelligent paradigms of fuzzy logic and/or neural networks in ship autopilot designs. After a brief review of the development of the first PID autopilots, the paper describes how early work using fuzzy logic techniques to describe and model the actions of helmsmen led to the development of the first fuzzy autopilots and how parallel advances in self-organising and adaptive network fuzzy inference systems were utilised to refine the early fuzzy autopilot designs. The use of artificial neural networks in adaptive and model reference approaches is also highlighted as is their use in optimising the parameters of neurofuzzy designs. The paper concludes with some observations on stability issues and suggestions for future developments in intelligent ship autopilots.     

Electromigration in fine-line conductors (0.45–2 μm)

The electromigration behaviour of various metallization systems has been tested on Si, GaAs and GaInAs substrates. Lifetime dependence on temperature and current density has been measured by accelerated lifetime tests. Linewidth was between 0.45 μm and 2 μm. The best electromigration resistance was found for electroplated gold lines, however also the system Al on Ti showed a as much as 40 times better performance than standard Al metallization. For linewidths of 0.45 μm a steep increase in stability has been found.     

Electrochromic Window Based on Conducting Poly(3,4‐ethylenedioxythiophene)–Poly(styrene sulfonate)

A short survey of technological aspects of electrochromism with various electroactive species is given. Different approaches with inorganic and organic materials have been pursued in the past. So far widespread usage of this technology for large area applications has not been achieved. Nevertheless one major technical product, self‐darkening rear‐view mirrors for cars, is already well established. This article reviews some research results on electroactive polythiophenes, especially poly(3,4‐alkylenedioxythiophenes). Some promising results with the commercially available electrically conducting polymer Baytron P (PEDT/PSS) are presented. It is demonstrated that an all solid‐state electrochromic multilayer assembly based on a polymeric electrochromic material might be close to technical realization. The coating of large area substrates with aqueous poly(3,4‐ethylenedioxythiophene)‐poly(styrenesulfonate) dispersion can be a way to an economically viable product.     

SEROS – A SELF-ROUTING OPTICAL ATM SWITCH

A fault-tolerant high-performance SElf-Routing 2 × 2 Optical ATM Switch (SEROS) is proposed. The switch is designed using all-optical components which allows the exploitation of spatial parallelism. SEROS can be used with any multistage interconnection network such as Omega, Banyan, Shuffle or Benes. For the purpose of this study, SEROS has been incorporated into a generic self-routing multistage interconnection network that uses 2 × 2 switches and is not fault tolerant. Reliability analysis is carried out and the results are compared with two major fault-tolerant networks. They show that without redundant switches, better network survivability is achieved. All the switches in the network are 2 × 2, making it easier to mass produce.     

VSP – A gate stack analyzer

An efficient software tool for investigations on novel stacked gate dielectrics with emphasis on reliability has been developed. The accumulation, depletion, and inversion of carriers in MOS capacitors is properly considered for n- and p-substrates. The effect of carrier quantization on the electrostatics and the leakage current is included by treating carriers in quasi-bound states (QBS) and continuum states. The effect of interface traps and bulk traps in arbitrarily stacked gate dielectrics is taken into account. Trap assisted tunneling (TAT) is incorporated assuming an inelastic single step tunneling process. A brief overview of implemented models is given. The capabilities of our tool are demonstrated by several examples.     

Third‐generation GPS: A low‐maintenance,high‐reliability future GPS system

This paper introduces the principles of the third‐generation Global Positioning Satellite (GPS) system, which is now in the early development phase. The new system has substantial advantages, including the elimination of the Doppler correction and signal tracking circuitry in the receivers. The benefits will be a significantly reduced receiver size and low‐maintenance requirements for the satellites. Another objective of the paper is to present a closed‐form solution for the GPS geolocation equations that does not depend on range data. Such a solution did not exist previously in the literature. Simulations that characterize the User Equivalent Range Errors in the new system are given. Copyright © 2010 John Wiley & Sons, Ltd.     

A maintenance planning and business case development model for the application of prognostics and health management (PHM) to electronic systems

This paper presents a model that enables the optimal interpretation of prognostics and health management (PHM) results for electronic systems. In this context, optimal interpretation of PHM results means translating PHM information into maintenance policies and decisions that minimize life cycle costs, or maximize availability or some other utility function. The electronics PHM problem is characterized by imperfect and partial monitoring, and a random/overstress failure component must be considered in the decision process. Given that the forecasting ability of PHM is subject to uncertainties in the sensor data collected, the failure and damage accumulation models applied, the material dimensions and properties used in the models, the decision model in this paper addresses how PHM results can best be interpreted to provide value to the system maintainer. The result of this model is a methodology for determining an optimal safety margin and prognostic distance for various PHM approaches in single and multiple socket systems where the LRU’s in the various sockets that make up a system can incorporate different PHM approaches (or have no PHM structures at all).The discrete event simulation model described in this paper provides the information needed to construct a business case showing the application-specific usefulness for various PHM approaches including health monitoring (HM) and life consumption monitoring (LCM) for electronic systems. An example business case analysis for a single socket system is provided.     

PVQM – A perceptual video quality measure

Modern video coding systems such as ISO-MPEG1,2,4 exploit properties of the human visual system, to reduce the bit rate at which a video sequence is coded, given a certain required video quality. As a result, to the degree in which such exploitation is successful, accurate prediction of the quality of the output video of such systems, should also take the human visual system into account. In this paper, we propose a perceptual video quality system, that uses a linear combination of three indicators. The indicators are, the “edginess” of the luminance, the normalized color error and the temporal decorrelation. In the benchmark by the Video Quality Expert Group (VQEG), a combined ITU-T and ITU-R expert group, the model showed the highest variance weighted regression overall correlation of all models.     

Miniaturised dielectrically-loaded quadrifilar antenna for globalpositioning system (GPS)

A new approach to designing a handset antenna for satellite applications is reported. It is based on precise control of the phasing between two bifilar helices, giving accurate resonant frequency position and radiation pattern volute. Results show an antenna with a gain of -2 dBi, 19 dB discrimination between the right and left hand circular polarisations and an axial ratio less than 1 dB. The front-to-back ratio is 24 dB. A return loss of 14.6 dB is also measured     

Synthesis,Morphology, and Properties of Poly(3‐hexylthiophene)‐block‐Poly(vinylphenyl oxadiazole) Donor–Acceptor Rod–Coil Block Copolymers and Their Memory Device Applications

Novel donor–acceptor rod–coil diblock copolymers of regioregular poly(3‐hexylthiophene) ( P3HT )‐block‐poly(2‐phenyl‐5‐(4‐vinylphenyl)‐1,3,4‐oxadiaz‐ole) ( POXD ) are successfully synthesized by the combination of a modified Grignard metathesis reaction ( GRIM ) and atom transfer radical polymerization ( ATRP ). The effects of the block ratios of the P3HT donor and POXD pendant acceptor blocks on the morphology, field effect transistor mobility, and memory device characteristics are explored. The TEM, SAXS, WAXS, and AFM results suggest that the coil block fraction significantly affects the chain packing of the P3HT block and depresses its crystallinity. The optical absorption spectra indicate that the intramolecular charge transfer between the main chain P3HT donor and the side chain POXD acceptor is relatively weak and the level of order of P3HT chains is reduced by the incorporation of the POXD acceptor. The field effect transistor (FET) hole mobility of the system exhibits a similar trend on the optical properties, which are also decreased with the reduced ordered P3HT crystallinity. The low‐lying highest occupied molecular orbital (HOMO) energy level (–6.08 eV) of POXD is employed as charge trap for the electrical switching memory devices. P3HT‐ b ‐POXD exhibits a non‐volatile bistable memory or insulator behavior depending on the P3HT / POXD block ratio and the resulting morphology. The ITO/ P3HT₄₄ ‐b‐ POXD₁₈ /Al memory device shows a non‐volatile switching characteristic with negative differential resistance (NDR) effect due to the charge trapped POXD block. These experimental results provide the new strategies for the design of donor‐acceptor rod‐coil block copolymers for controlling morphology and physical properties as well as advanced memory device applications.     

A study of the quadrifilar helix antenna for Global PositioningSystem (GPS) applications

An analytic model for computing the radiation properties of the quadrifilar helix volute antenna is discussed and various design considerations for GPS applications are presented. The effects of modifying the antenna length and diameter on the antenna amplitude and phase performance are presented, and using the antenna for dual-frequency operation is discussed. The effects of phase imbalances are presented and compared with measured pattern anomalies     

A 3–8 GHz Low-Noise CMOS Amplifier

A wideband CMOS low-noise amplifier (LNA) is proposed by using the concept of mutual coupling technique implemented through a symmetric center-tap inductor. A frequency widening network is designed with a center-tap inductor at the input and the output of an LNA to achieve bandwidth extension with a single stage amplifier. The proposed wideband low noise amplifier is implemented in the 0.18 mum CMOS technology. This design obtains a bandwidth of 3-8 GHz with a power consumption of 3.77 mW from a 1.8 V supply.     

Reliability evaluation of ultra-thin CSP using new flip-chip bonding technology––double-sided CSP and single-sided CSP

A high-density packaging technology has been developed that uses new flip-chip bonding technology with a thin IC and a thin substrate. Numerical analysis with the finite element method as well experiments clearly showed that deflection of the IC and reliability were affected by the IC thickness. Consequently, reliability could be improved by reducing IC thickness. The dependency of the life in single-sided chip-size packages (CSPs) could be expressed using a normal stress value in thickness, which is computed by the IC thickness and substrate type and thickness. The dependency of the life in double-sided CSPs could be expressed using a shear stress value in the vertical cross section, which is computed in IC thickness and substrate type and thickness, respectively.Moreover, a double-sided flip-chip approach solved the problem of warpage. A high-capacity memory card of 512 MB was put to practical use by applying these results. This increased the Si density by four times over that of a conventional CSP.     

Micrometer patterning using synchrotron radiation and the polyaniline – PVC blend

In the present work we investigated the localized photodoping process of polyaniline‐emeraldine base/poly(vinylchloride) blends by high‐energy photons from a synchrotron source. The doped blend was characterized using optical and electrical parameters. An abrupt increase of conductivity by four orders of magnitude (10⁻¹⁰ to 10⁻⁶ Scm⁻¹) was observed using an initial dose of 500 Jcm⁻³. Lithographic patterns were recorded with micrometer resolution. Copyright © 2000 John Wiley & Sons, Ltd.     

A 500‐kW PV generator I–V curve

This paper presents the measurement of the I–V curve of a 500‐kW PV generator by means of an own‐made capacitive load. It is shown that I–V curve analysis can also be applied to big PV generators and that when measuring the operation conditions with reference modules and taking some precautions (especially regarding the operation cell temperature), it is still a useful tool for characterizing them and therefore can be incorporated into maintenance procedures. As far as we know, this is the largest I–V curve measured so far. Copyright © 2013 John Wiley & Sons, Ltd.     

A combined optical–wireless indoor communication system

This new combined optical–wireless indoor communication system provides an economic and flexible approach for local area networks mainly in large buildings or in a group of several buildings. The radiation from the radio base stations of mobile networks cannot penetrate into large buildings completely. That problem is more serious at higher frequencies. The present approach offers a good solution to this problem. In this approach the wireless communication serves small picocells which are interconnected by an optical backbone. The performance of the system is enhanced by assigning a specific radio frequency for each picocell which enables the transmission of the wireless channels without altering their modulation formats. This method allows for a simple, and low-cost indoor communication system.