163 research outputs found

    New advances in vehicular technology and automotive engineering

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    An automobile was seen as a simple accessory of luxury in the early years of the past century. Therefore, it was an expensive asset which none of the common citizen could afford. It was necessary to pass a long period and waiting for Henry Ford to establish the first plants with the series fabrication. This new industrial paradigm makes easy to the common American to acquire an automobile, either for running away or for working purposes. Since that date, the automotive research grown exponentially to the levels observed in the actuality. Now, the automobiles are indispensable goods; saying with other words, the automobile is a first necessity article in a wide number of aspects of living: for workers to allow them to move from their homes into their workplaces, for transportation of students, for allowing the domestic women in their home tasks, for ambulances to carry people with decease to the hospitals, for transportation of materials, and so on, the list don’t ends. The new goal pursued by the automotive industry is to provide electric vehicles at low cost and with high reliability. This commitment is justified by the oil’s peak extraction on 50s of this century and also by the necessity to reduce the emissions of CO2 to the atmosphere, as well as to reduce the needs of this even more valuable natural resource. In order to achieve this task and to improve the regular cars based on oil, the automotive industry is even more concerned on doing applied research on technology and on fundamental research of new materials. The most important idea to retain from the previous introduction is to clarify the minds of the potential readers for the direct and indirect penetration of the vehicles and the vehicular industry in the today’s life. In this sequence of ideas, this book tries not only to fill a gap by presenting fresh subjects related to the vehicular technology and to the automotive engineering but to provide guidelines for future research. This book account with valuable contributions from worldwide experts of automotive’s field. The amount and type of contributions were judiciously selected to cover a broad range of research. The reader can found the most recent and cutting-edge sources of information divided in four major groups: electronics (power, communications, optics, batteries, alternators and sensors), mechanics (suspension control, torque converters, deformation analysis, structural monitoring), materials (nanotechnology, nanocomposites, lubrificants, biodegradable, composites, structural monitoring) and manufacturing (supply chains). We are sure that you will enjoy this book and will profit with the technical and scientific contents. To finish, we are thankful to all of those who contributed to this book and who made it possible.info:eu-repo/semantics/publishedVersio

    RF CMOS transceiver at 2.4 GHz in wearables for measuring the cardio-respiratory function

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    This paper presents a radio-frequency (RF) transceiver for operation in the 2.4 GHz ISM band. The RF CMOS transceiver can be supplied with only 1.8 V, and it was designed to establish wireless links for distances up to 10 m, for a maximum baud-rate of 250 Kbps with a Bit Error Probability less than 10 6. The transmitter can deliver a output power of 0 dBm with a consumption of only 11.2 mW, while the receiver has sensitivity of 60 dBm and consumes only 6.3 mW. The goal of RF CMOS transceiver is for co-integration with sensors in the same die using microsystems techniques. The target application of such microsystems is in wearables (e.g., in wireless electronic shirts) for measuring biomedical data of patients. The wireless electronic shirt (WES) measures the heart rate and the respiratory frequency, and at the same time it allows patients to maintain their mobilit

    Microlenses for stereoscopic image formation

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    This paper presents microlenses for integration on a stereoscopic image sensor in CMOS technology for use in biomedical devices. It is intended to provide an image sensor with a stereoscopic vision. An array of microlenses potentiates stereoscopic vision and maximizes the color fidelity. An array of optical filters tuned at the primary colors will enable a multicolor usage. The material selected for fabricating the microlens was the AZ4562 positive photoresist. The reflow method applied to the photoresist allowing the fabrication of microlenses with high reproducibility.This work was fully supported by the Portuguese Foundation for Science and Technology under the project FCT/PTDC/EEA-ELC/109936/2009

    Maximum power point tracking CMOS circuit to connect a solar cell into a solid-state battery

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    This paper presents a Maximum Power Point Tracking (MPPT) circuit in CMOS technology for integration into an energy harvesting solution, comprising a solid-state thin-film lithium battery fabricated in the back side of a plastic solar cell. The MPPT CMOS circuit is required in the energy transfer process from the solar cell to the battery. The MPPT circuit was designed in the 0.7 µm CMOS process from on semiconductor (former AMIS, Alcatel-Mietec). The pulse width modulation (PWM) gate control of the DC-DC step-up converter is obtained only with analog circuits, which are composed by rail-to-rail operational amplifiers, analog multipliers and a ring oscillator. The ripple correlation control algorithm is used in the implementation of the analog MPPT circuit. This is a dynamically rapid method (e.g., 5 ms step response was measured) where the inevitable ripple of the inductor current of the DC-DC converter is analyzed and used to adjust the set-point of the same DC-DC converter. The full energy harvesting is also described in this paper

    Thermoelectric microconverter for energy harvesting systems

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    This paper presents a solution for energy microgeneration through energy harvesting by taking advantage of temperature differences that are converted into electrical energy using the Seebeck effect. A thermoelectric microconverter for energy scavenging systems that can supply low-power electronics was fabricated using thin films of bismuth and antimony tellurides. Thin films of n-type bismuth (Bi2Te3) and p-type antimony (Sb2Te3) tellurides were obtained by thermal coevaporation with thermoelectric figures of merit (ZT) at room temperature of 0.84 and 0.5 and power factors (PF × 10−3 [W · K−1 · m−2]) of 4.87 and 2.81, respectively. The films were patterned by photolithography and wet-etching techniques. The goal for this thermoelectric microconverter is to supply individual electroencephalogram (EEG) modules composed by an electrode, processing electronics, and an antenna, where the power consumption ranges from hundredths of microwatts to a few milliwatts. Moreover, these wireless EEG modules allow patients to maintain their mobility while simultaneously having their electrical brain activity monitored.Portuguese Foundation for Science and Technology - Project FCT/PTDC/EEA-ENE/66855/200

    A flexible infrastructure for dynamic power control of electric vehicle battery chargers

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    This paper proposes a Flexible Infrastructure for Dynamic Power Control (FIDPC) of Electric Vehicle (EV) Battery Chargers. This infrastructure dynamically adjusts the EV battery charger current, according to the power demand of the home wherein the vehicle is plugged. An infrastructure was implemented to validate this proposal. Such infrastructure is composed by an EV battery charger and a communication system based on a Radio Frequency interface. The battery charger has nominal power of 3.6 kVA and operates with sinusoidal current and unitary total power factor, while the RF interface provides continuous data flow to the battery charger with information about the home total current consumption (rms value). Experimental tests were performed under realistic conditions to validate the concept behind the proposed FIDPC. These tests served to assess the behavior of the EV battery charger with dynamic power control on a single-phase, 230 V, 16 A, 50 Hz residential electrical installation. The experimental results confirm the quick time response of the FIDPC even when working under heavy home load variations.This work was supported by the Fundacao para a Ciencia e Tecnologia (FCT) through Project PEst-UID/CEC/00319/2013. The work of V. Monteiro was supported by the FCT agency through a doctoral scholarship under Grant SFRH/BD/80155/2011. The review of this paper was coordinated by Dr. D. Cao

    On-chip CMOS wireless sensors interface for automotive applications

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    This paper describes a CMOS interface for short-range wireless sensor networks. The sensor interface is composed by the sensor readout and a transceiver in CMOS 0.18 µm process technology and a patch antenna at 5.7 GHz frequency, 50 MHz bandwidth and an efficiency of 18%. Automotive applications are the target of this wireless sensor interface

    5.7 GHz on-chip antenna/RF CMOS transceiver for wireless sensors network

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    This paper describes a chip-size antenna for operation at 5.7 GHz, assembled with a low-power, low-voltage RF CMOS transceiver, fabricated in UMC RF CMOS 0.18 µm process. Measurements shown a patch antenna with the central frequency of 5.705 GHz, a bandwidth of 90 MHz at –10 dB of return loss, a directive gain of 0.3 dB, with an efficiency of 18%, and a transceiver with a measured total power consumption of 23 mW

    Low f-number microlenses for integration on optical microsystems

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    This paper presents microlenses (MLs) with low f-number made of AZ4562 photoresist for integration on optical microsystems. The fabrication process was based on the thermal reflow and rehydration. Large series of MLs were fabricated with a width of 35 μm, a thickness of 5 μm, and spaced apart by 3 μm. The MLs were fabricated directly on the surface of a die with type n+/p-substrate junction photodiode fabricated in a standard CMOS process. The measured focal length was 49 μm with a tolerance of ±2 μm (maximum error of ±4%), resulting in a numerical aperture of 33.6 × 10-2 (±1.3 × 10-2). The measurements also revealed an f-number of 1.4.This work was sponsored by the Brazilian agency Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq) under the grant 400110/2014-8: Ciencia sem Fronteiras, Bolsa Pesquisador Visitante Especial (PVE) 2014. The associate editor coordinating the review of this paper and approving it for publication was Prof. M. Nurul Abedin

    Super-regenerative receiver at 433MHz

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    This paper presents a receiver for operation in the 433 MHz ISM band. The selected architecture explores the super regeneration phenomena to achieve a high sensitivity for applying in wireless implantable microsystems. This radio frequency (RF) chip can be supplied with a voltage of only 3 V for demodulating signals with powers in the range [ 100, 40] dB. The codulation (modulation and coding) scheme of the binary data is a variation of the Manchester code combined with OOK (on/off keying) modulation. The AMIS 0.7 µm CMOS process was selected for targeting the requirement to fabricate a low cost receiver, whose prototype was integrated in a die with an area of 55 mm2. Also, this receiver is fully compatibility with commercially transmitters for the same frequency
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