1,720,990 research outputs found
An overview on state-of-art and future application fields of BLDC motors : design and characterization of a PC-interfaced driving and motion control system
Full text linkNew generations of equipments must have better performances respect to the previous generations, such as higher efficiency, low power consumption, reduced electromagnetic interference, small dimensions, lightness and so on; all these improvements must be achieved while maintaining, at the same time, systems cost as low as possible. Brush-Less Direct
Current (BLDC) motors, employed even more in the last years in many equipments in various application fields, present low maintenance costs, compact size, high reliability, efficiency, low power consumption and other optimum features, proposing themselves as excellent candidates for satisfying the stringent requirements mentioned previously. In this paper,
after a detailed overview on the current and possible future application fields of BLDC motors, from home appliances, to automotive, industrial automation, medical equipments and robotic instrumentation, the design and realization of a driving and control system of a BLDC motor, with Hall sensors embedded, is presented. A BLDC motor is provided by permanent
magnets on moving part (rotor) and windings on fixed part (stator); energized stator windings create electromagnetic poles and the rotor (equivalent to a bar magnet) is attracted by the energized stator phase. By using appropriate sequence to supply stator phases, a rotating field on stator is created and maintained. The lead between rotor and rotating field must be
controlled to produce torque and this synchronization implies accurate knowledge of rotor position which is obtained by means of the embedded Hall effect sensors. The realized driving system is composed by three principal blocks: the control electronic board, the power driving board and the BLDC motor. By PC connected via USB with the driving board, the user
can choose the motor rotation direction, set the desired rpm value and, by varying potentiometer value located on board, change the rotation speed. Different tests were performed for verifying the correct motor operation and the results show that all the employed devices, driving board, control board and BLDC motor, work properly
Solar-powered LED-based lighting facilities: an overview on recent technologies and embedded IoT devices to obtain wireless control, energy savings and quick maintenance
Full text linkAim of this paper is to illustrate and describe the trend of last technological innovations and new IoT-based devices employed in solar-powered LED-based lighting systems, in order to obtain energy savings, low mainteinance costs and to offer additional services to the users or community. Technological developments, in the last years, have allowed the use of LEDs technology in many general illumination applications, from houses to commercial or outdoor spaces. LED lighting is projected to reduce related energy consumption of 15% in 2020 up to 40% in 2030; in this contest, solarpowered LED lighting facilities offer a significant contribution to obtain energy savings, together with substantial environmental and health benefits. Last innovations in nanotechnology and quantum physics have the potential to strongly increase the electrical power obtained from solar panels for feeding any portable device. Furthermore, the spread of Internet of Things (IoT) and the huge use of smartphones and related apps allow wirelessly to control and drive the LED-based lighting systems, that also can be provided with integrated sensors thus realizing new functionalities, an improved management of energy and new services for smart cities. Finally, systems made up of connected lighting devices could
become data collection platforms that, making use of renewable energies, enable even greater energy savings referred to
lighting and in general electrical facilities present in smart buildings or cities
Solar Powered Wireless Monitoring System of Environmental Conditions for Early Flood Prediction or Optimized Irrigation in Agriculture
Full text linkThis paper describes the design and realization of a smart electronic system, based on a Wireless Sensor Network, for wide-area monitoring of availability level and rapid changes of the water presence in the monitored soil, in order to guarantee, depending on application, early flood prediction, water savings in the optimized farmland irrigation as well as waste reduction and optimal use of water resources where its availability is low. The designed sensor node, equipped with a small PV panel to recharge the Li-Ion battery for feeding the entire system, by means of the different embedded sensors, is capable of detecting environmental parameters, the solar radiation level and soil temperature and moisture (i.e.water volume content) values. The sensors communicate with a central processing unit located on board, the ESP8266 SoC module, used both as data processing unit and as Wi-Fi transceiver to receive/transmit sensors data; the user near a sensor node, by a tablet or smartphone with an appropriate app, can collect information provided from sensors and share them with all users who use the same app, through peer to peer Wi-Fi or other internet connection
An overview on state-of-art energy harvesting techniques and related choice criteria: a WSN node for goods transport and storage powered by a smart solar- based EH system
No full textThis paper describes a solar-based harvesting system able to properly power supply the sensor node of a Wireless Sensor Network (WSN) developed for ensuring traceability and services relatively to goods stored in containers placed in the monitored areas (e.g commercial seaport). Battery life-time is a main problem especially in networks where sensor nodes are not easily accessible. For this reason, sensor nodes are equipped with power management devices able to supply power, in an intelligent way, from the harvester when harvestable energy is available or from backup batteries, ensuring, under every operating conditions, the correct functioning of node. In this research work, an overview of the available energy harvesting technologies, showing some related devices present on the market, is presented; subsequently, the suitable energy harvesting technique for power supply the designed WSN node was chosen. Hence the smart node able to monitor the physical parameters deemed of interest related to stored goods and a solar-based harvesting board, based on LTC3330 IC, were designed and tested. Supercapacitors are charged when harvestable energy is higher than the one required from node; stored energy is then used in time periods with no harvestable energy before requiring the backup battery intervention
Design and Testing of a Control System Based on STM X-Nucleo Development Boards for Detection and Wireless Transmission of Sensors Data Applied to a Single-Seat Formula SAE Car
Full text linkThe emerged potentials and opportunities in the electronics field are becoming greatly appreciated in a highly competitive environment such that of the mechanic/engine field. In fact, the electronic system integrated in a vehicle is playing an increasingly fundamental role, especially in the competition/races sector, such that related to the “Formula SAE” (Society of Automotive Engineers), a competition in which participating teams (eg the Salento Racing Team) compete in the design, construction and testing of prototype single-seater cars (Fig. 1(a)). In this research work, an electronic system able to monitor in real time and constantly principal parameters characterizing the moving vehicle and to transmit wirelessly the acquired data was realized [1, 2]. Different sensors, mounted on vehicle, exchange data with the data acquisition and wireless communication control unit (Fig. 1(b)): linear potentiometers in order to monitor the suspensions behavior, temperature transducers located inside the engine compartment, gyroscope/accelerometer for detecting the accelerations and the inclination angles in space (i.e. pitch, roll and yaw), one NTC thermistor for acquiring the cooling liquid temperature and Hall effect sensors for monitoring the vehicle speed and any slippage of the wheels [3]. Besides, the realized data acquisition board, shown in Figs 2a and 2b, is composed of a conditioning board, for adjusting the voltage value of signals provided by sensors in accordance to voltage values required by the STM-32 Nucleo F411RE development board, which processes received data and, by means of the DORJI DRF1278F WiFi radio module, sends them to the base station (Fig. 2c) [4]. A further component is the SPARKFUN CAN-BUS shield module employed for data storage on SD memory card and for establishing the communication between the STM board and the engine control unit which receives signals from Hall sensors and from the NTC thermistor. The developed firmware (flow chart shown in Fig. 3), installed on STM32F411RET6 microcontroller embedded on STM board, allows the reading of signals provided by sensors, the SPARKFUN CAN module management and wireless transmission data through DORJI WiFi module. In Fig. 4, graphs relative to the sent data to the base station, concerning the vehicle speed, suspensions behavior and cooling liquid temperature monitoring, are shown. As reported in the graphs, data are correctly received by the base station and they show accordance between themselves, confirming, in this way, the proper functioning of the developed data acquisition and wireless transmission systems
Wireless Monitoring System of Household Electrical Consumption with DALY-based Control Unit of Lighting Facilities Remotely Controlled by Internet
Full text linkAim of this paper is to present a wireless monitoring smart system of household electrical facilities, with ZigBee/WiFi transceivers, able to detect absorbed current from electrical loads, to calculate dissipated power and energy by means of PIC-based software and to view, in real-time, calculated consumption values on web page properly realized for user’s remote control. Depending on light/presence sensors’ signal, the realized system can switch on/off the monitored electrical loads for obtaining energy saving and user satisfaction. Also by sending DALI-standard commands to slave loads (e.g lighting facilities based on LEDs), the user can monitor, remotely by using a tablet/smartphone connected to internet, the operation’s state and adjust the light intensity of each light point for achieving different scenarios. All functional tests, carried out on realized PCB prototype, have provided positive results allowing the use for the monitoring/driving of a real house’s electrical facilities
Electronic Control System of LED-Induced CNTs Photo-Ignition for Improved Fuels Combustion in Advanced Engines
Full text linkThe use of carbon nanotubes (CNTs) in the combustion and propulsion sector, which is the object of this work, is due to the discovery of photo-ignition properties of such nano-material, when they are exposed to an intense luminous flash [1]. This phenomenon allows obtaining fuels combustion system more efficient and clean (HCCI engine) [2]. Most of the literature studies involve a Xe-lamp to ignite the CNTs mixed with metal catalyst; the use of this light source is not without criticism because it requires very high supply voltages, has an intrinsic mechanical instability, and it can’t work at frequencies required by an automotive engine running [3]. A LED-based ignition system can be considered the optimum solution, because LEDs have high luminous efficiency, higher mechanical stability and for the absence of frequency limitations. In this work, a LEDs-based experimental setup used to perform combustion tests of gaseous fuels, by means of photo-ignition of MWCNTs/FeCp2, has been proposed (Fig. 1). The setup uses a multi-LED ignition-system, placed outside the combustion chamber, convoying the light emitted by each LED source into the chamber by a fiber optic. The electronic section drives and controls the LED sources, synchronizing temporally them with the input of the enriched air-fuel mixture. Moreover, it will also handle and monitor all physical / environmental parameters involved in the combustion process, such as temperature and pressure inside the combustion chamber, etc. In order to obtain a light pulse of controlled duration, a driving and control electronic system was realized (Fig. 2). The white power LEDs (Cree XHP70) were driven by proper LED drivers; to generate a single light pulse, a pulsed signal is applied to the enable control input of each LED driver. This last signal is obtained on PC audio channel by proper LabVIEW application and after conditioning by an interface board. A four LEDs source was used to perform ignition tests on the dry mixtures MWCNTs/FeCp2 to obtain energy density comparable to which obtained with the Xe lamp. In the Figs. 3a and b, the setup used to perform ignition tests on dry mixtures MWCNTs/FeCp2, is shown; the driving and control unit is constituted by four LED drivers, the interface board and the PC with LabVIEW application (Fig. 3a), whereas tests area with the four LEDs source and the power/energy meter (Thorlabs PM100D) equipped with pyroelectric sensor (Thorlabs ES145C) are shown in Fig. 3b. The light source is placed at 1cm at least from the pyroelectric sensor and then from CNTs sample (Fig. 3b). Using this experimental setup, the minimum pulse durations needed to ignite the MWCNTs/FeCp2 samples for the different concentrations by weight, are determined. Known the light source intensity, the minimum ignition energy of the MWCNTs/FeCp2 samples for the considered concentrations, are calculated (Fig. 4)
An Innovative Approach for Monitoring Elderly Behavior by Detecting Home Appliance’s Usage
No full textDetecting how elderly people interact with their surrounding environment, especially with domestic electrical appliances, is an important parameter to assess Mild Cognitive Impairments and frailty issues. This paper proposes an innovative approach for monitoring elderly behavior by detecting
home appliance’s usage. It is based on an unobtrusive smart meter that periodically measures the global power consumption in the house, associated with some smart plugs for punctually monitoring specific electrical devices. This infrastructure has been implemented and validated within the Personal Data Capturing System of the City4Age Platform, where, joined with other provided monitoring systems, can feed risk detection
algorithms with more accurate data. Summarizing, implemented system, although simple and at low cost, is able to combine data provided by designed power meter with those of smart meter plugs and, by means of implemented algorithms, to detect unusual elder behavior, moreover resulting reliable and accurate
MEASUREMENT AND CONTROL SYSTEM FOR THERMO-SOLAR PLANT AND PERFORMANCE COMPARISON BETWEEN TRADITIONAL AND NANOFLUID SOLAR THERMAL COLLECTORS
Full text linkAim of this work is the design of a programmable electronic system for monitoring the environmental parameters and managing the electrical functions of a thermo-solar plant. The designed control unit detects data from temperature and light sensors, processes acquired information and commands external equipments (pumps, electric valves and power supplies) in order to optimize plant performances and maximize efficiency and energy savings. Recently several researches, in the field of solar thermal energy production, have demonstrated that nanofluid-based solar collectors present higher conversion efficiency. In this context, the designed control unit can be used to detect their operation parameters in order to compare the performances of nanofluid- based solar collector with those of traditional one. The electronic experimental setup is capable to monitor, at the same time, the two different types of solar collector in similar environmental conditions and to show on touch screen display the detected performances. In order to have reference data, experimental measurements have been carried out by using traditional water and Al2O3–based nanofluid thermo solar collectors. The obtained experimental data showed the benefit in terms of efficiency in the use of nanofluid as heat transfer fluid in such a system
Morphological analysis of injected sprays of different bio-diesel fuels by using a common rail setup controlled by a programmable electronic system
Full text linkBiodiesel fuels are increasingly attracting interest in the scientific community and in the world motor industry. The morphological analysis of injected sprays is a key factor to
increase engine performances using new biodiesel fuels and to compare them with those related to the use of conventional fuels. In this paper, an experimental setup is realised to carry out test campaigns, in order to analyse and compare the spray injections of different fuel typologies. A PC-interfaced electronic system was realised for driving BOSCH injectors and for varying the injection pressure and opening time. Hence, the morphological analysis was performed for each tested fuel by characterising the shaperatio and penetration depth inside the velocimetric chamber. The results show higher penetration values for biodiesel fuels due to their viscosity and drops in superficial
tension, which facilitate a deeper penetration compared to those obtained with conventional diesel fuels. Although used biodiesels contain only 20% of renewable vegetable-origin diesel fuels, the viscosity and superficial tension are slightly higher than those of petroleum diesel, thus determining a weak vaporisation and formation of larger drops. By knowing the morphological behaviour of sprays using biofuels and conventional fuel, it is possible, by using programmable electronic systems, to adjust and improve the spray parameters in order to obtain better engine performances. The results reported in this instance could be utilised by future research works for choosing the most
suitable biofuel based on the desired morphological behaviour of the injected sprays
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