1,721,171 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
Controllo Cycle-Resolved delle Emissioni nei Motori a Combustione Interna Mediante un Innovativo Sensore Ottico
Full text linkPRIN 2005
Il programma di ricerca si propone di sviluppare un innovativo sistema per la misura cycle-resolved delle emissioni di NOx e CO nei motori a combustione interna e del relativo sistema di controllo.
Attraverso la misura cycle-resolved delle emissioni nei gas di scarico si intende effettuare il controllo retroazionato e l’adeguamento in tempo reale dei parametri che regolano il processo di combustione, quali per esempio la pressione di iniezione, il numero delle iniezioni per ciclo ed il loro posizionamento, il livello di EGR, ecc., al fine di ottimizzare, anche in regime transitorio, il consumo di carburante e le emissioni. Grazie al monitoraggio on line delle emissioni sarà, inoltre, possibile compensare eventuali perdite di prestazioni dovute all’usura dei componenti installati. Il sistema che si intende sviluppare consiste di un elemento sensibile a base di nitruro di gallio e alluminio (Alx-Ga-Nx) in grado di rilevare la variazione dello spettro emesso da una sorgente luminosa al variare della concentrazione dei gas combusti, da una sorgente luminosa che emetta nella regione spettrale dell’UV e da un sistema di controllo motore in grado di sfruttare il segnale del sensore. Il principale problema che ha impedito l’uso di sensori ottici per la rilevazione delle emissioni in campo automobilistico è che essi tendono a sporcarsi a seguito della deposizione di particelle di carbonio e di altre sostanze organiche provenienti dal combustibile in uso e dagli oli necessari per la lubrificazione.
Nell’ambito del presente progetto tale problema sarà risolto per la parte sensibile mediante l’uso di nitruri di gallio e alluminio che consentono la realizzazione di un sensore in grado di lavorare ad una temperatura di esercizio superiore a quella di ossidazione del carbonio e delle altre sostanze organiche presenti nei gas di scarico impedendo così lo sporcamento del sensore stesso. Invece, per evitare lo sporcamento della sorgente luminosa si utilizzerà come sorgente UV un arco voltaico che verrà fatto scoccare fra due elettrodi opportunamente posizionati rispetto al sensore.
Per il sensore e la sorgente luminosa, verrà, quindi, studiato un opportuno packaging che ne consenta la facile installazione nei condotti di scarico di un motore alternativo ed un rapido collegamento con la parte di controllo e acquisizione del segnale.
Infine, con questo progetto si svilupperà un sistema di controllo motore in grado di utilizzare il segnale del sensore per effettuare un controllo cycle-resolved del motore
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
Smart electronic system for dancing fountains control capable to create water and lighting scenarios synchronized with a music track
Full text linkThis work regards on hardware and firmware development of an electronic control and driving system for dancing fountains, able to manage water and lighting scenarios synchronized with mp3 music files stored on an external SD memory card connected to the designed system. The smart PIC-based control unit reproduces the music file related to a particular scenario and drives, in a synchronized way, fountain’s LED-based headlights and water pumps to create amazing light and water plays
Development of smart PIC–based electronic equipment for managing and monitoring energy production of photovoltaic plan with wireless transmission unit
Full text linkAim of this paper is to present a PIC-based low-cost monitoring system for domestic PV plant, able to detect environmental and electrical parameters for controlling energy production and its proper functioning. Thereby the designed equipment can guarantee, by sending alarm signal to a data/receiving viewing device, quick detection in case of system’s malfunction or productivity’s drops. In fact realized system is able to transmit by wireless ZigBee module, the PIC processed data about PV plant’s status and productivity to a remote device, touch screen display or PC, for viewing the information to the user
Thermo-solar plant managing and monitoring by electronic programmable device with touch-screen interface and local or remote control possibility
Full text linkThis paper describes a programmable electronic
equipment for controlling the environmental parameters and
managing the electrical functions of a thermo-solar plant. The
control unit acquires data from analog sensors, processes these
information and commands external actuation devices in order
to optimize plant performances improving efficiency and energy
saving. The designed electronic system has a touch-screen
display for graphical interface with users, which makes device
programming and managing operations easier. In addition to,
the system is accessible via PC terminal on site by RS232 serial
cable and from Android-based mobile devices connected to
internet network for remote monitoring, since control unit is
connected to a modem/router device with an RS485/Ethernet
adapter
Wide band gap amorphous hydrogenated carbon films grown by plasma enhanced chemical vapor deposition
Full text linkWe have fabricated amorphous hydrogenated carbon films by rf plasma enhanced chemical vapor deposition with very low ion bombardment energy. We demonstrate that the optical gap of the films can be tuned in a wide range, from 3.46 up to 4.95 eV, i.e., close to the diamond gap ~5.5 eV!, by proper control of the negative dc self-bias voltage. This behavior suggests that a dramatic reduction in the content and clustering of the sp2 sites occurs by lowering the ion bombardment energy
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
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