Navegando por Assunto "Sensores"

Agora exibindo 1 - 5 de 5

Acesso aberto (Open Access)
Controlador fuzzy para uso em conversores de frequência aplicado à sistemas fotovoltaicos de bombeamento
(Universidade Federal do Pará, 2015-11-06) MARANHÃO, Geraldo Neves de Albuquerque; BRITO, Alaan Ubaiara; http://lattes.cnpq.br/9194391143997588; MACÊDO, Wilson Negrão; http://lattes.cnpq.br/3386249951714088
This work proposes a fuzzy controller applied to a commercial variable-speed drive (VSD) for use in direct-coupled photovoltaic pumping systems (PVPS). The fuzzy logic system used is embedded in a controlling programming device (CPD) connected to the auxiliary input of the VSD for controlling the pump's working speed according to the power provided by photovoltaic generator (PVG). The objective is to avoid unintended behaviors in the d.c. bus voltage level VSD and cause the system to operate near the point of maximum efficiency. The control methodology is based on achieving the dynamic be-havior of the irradiance with which the PVPS is subjected via two different methods of low cost sensing, namely: using a light-dependent resistor (LDR) and using a low power sensor module. Experimental tests were performed using two tests bench for motor pumps able to simulate several-head wells. The results confirm the feasibility of using fuzzy con-troller with both sensing methods. Using LDR it possible to ensure the availability of PVPS, since it could suppress the undesired undervoltage errors, as with the methodology using the sensor module, and ensure availability of the system was obtained also satisfac-tory yield assembly VSD + motor pump, with a daily average efficiency of approximately 23 %.
Acesso aberto (Open Access)
Desevolvimento de dispositivos eletrônicos orgânicos nano e micro-estruturados: memória volátil, sesores e fotocélulas
(Universidade Federal do Pará, 2011-02-14) REIS, Marcos Allan Leite dos; DEL NERO, Jordan; http://lattes.cnpq.br/5168545718455899
In this work, several nano and microstructured organic devices were developed based on molecules of 4-dimethyl amino azobenzene-2-carboxylic acid (Methyl Red – VM), C60 Fullerene, nanocomposite of Aluminum/Carbon Nanotubes (Al/NC) and polymers: Poly(3, 4- dioxithiophene ethylene)-poly(sulfonate stireno) – PEDOT-PSS and poly(3-hexiltiofeno) – P3HT. These devices are volatile memory, fuel sensors, thermal-piezoresisitive sensor and photocells, which were manufactured by spin-coating, drop casting and chemical vapor deposition, resulting in devices with planar or layer by layer geometry. Morphological, optical, electrical and thermal characterizations were performed on devices, resulting: (a) volatile memory with a bit retention time of 4.5 s, the characteristic curves of current vs. voltage with peak-valley ratios of 8: under a 10:1 voltage positive and negative electrical energized with electrical conductivity of 10-4 S / m (OFF state) to 3.10 S / m (ON) at room temperature, (b) fuel sensors like chemiresistor sensors characteristics with sensitivity to ethanol and gasohol in concentrations of 26.25 ppm, (c) thermal-piezoresistive sensor with polynomial relationship between temperature and electrical resistance, linear relationship between pressure and electrical resistance, more accurate than a K type thermocouple when compared to a mercury thermometer at room temperature, (d) photocells with better performance when doped by Methyl Red showed quantum efficiencies up to 0.04%, real power at 0.27 and power conversion efficiency of 2.0%. These results indicate that electronic devices developed showed a better performance in comparison to similar organics.
Acesso aberto (Open Access)
Estimação do local de incidência da descarga atmosférica utilizando o método TOA e tempos artificiais de detecção dos sensores
(Universidade Federal do Pará, 2016-03-22) MIRANDA, Bruno Nazareno Prazeres de; MACEDO, Valquiria Gusmão; http://lattes.cnpq.br/4288739747304808; ROCHA, Brigida Ramati Pereira da; http://lattes.cnpq.br/9943372249006341
Over the years, lightning were the central point of researches in various scientific communities around the world, no doubt for its aggressive and devastating nature, but mostly for damage caused in the electricity sector, so it is necessary to clarify what is and what it is for a Lightning Location System (LLS). This work proposes to demonstrate the operation of the algorithm utilized in LLS that is used to locate in geographical terms, lightning, using the arrival times of electromagnetic signals in the sensors. In order to prepare this paper it was used the data format generated by LPATS IV sensors belonging to Amazon Protection System (SIPAM). These data were generated in an artificial way for use in the algorithm tests. The lightning location will be based on a finite sequence rules that use the intersection of hyperbolas, resulting from the difference of arrival times at each sensor. The algorithm is able to identify the lightning location incidence using a system with three sensors. Each pair of sensors defines two hyperbole forming a total of six, because each hyperbole has a bright side and a negative side, so there will be two intersections of three hyperboles. For analysis of the results is considered the nearest crossing point to the sensor that identified the electromagnetic disturbance faster. Studies about atmospheric electricity, lightning types, electromagnetic radiation during storms, types of electromagnetic sensors and lightning detection networks have given the knowledge to develop the algorithm.
Acesso aberto (Open Access)
Prototipagem de sistema de alarme de incêndio baseado em sensor nanoestruturado integrado a IoT
(Universidade Federal do Pará, 2021-06-29) FREITAS, Luís Gustavo Oliveira de; REIS, Marcos Allan Leite dos; http://lattes.cnpq.br/8252507933374637
The improvement of remote sensing systems for the detection of forest fires or industrial plants is fundamental to the development of industry 4.0, and it is becoming increasingly important for many countries where forest fires occur frequently. Therefore, it is necessary to design and explore a device that has a quick response, that has remote monitoring in real time and can generate warning signs that precede major fires in indoor (indoor) and outdoor (outdoor) environments, this nanostructured sensor based on buckypaper that it consists of carbon nanotube films and has thermal sensitivities that can be measured in short response times. In the prototyping of the fire alert sensor, thermal tests were carried out to evaluate the effectiveness. Furthermore, it was integrated with IoT (Internet of Things) using the NodeMCU architecture together with the MQTT (Message Queuing Telemetry Transport) protocol, thus enabling the sending of the alert message to the end user through an Android application. Preliminary results show that this nanostructured sensor can be effective at distances of less than 1 meter from the fire source, for example at 20 cm, generating a thermovoltage of 2.3 mV over 80 seconds with a heat source at 240 ° C. This work shows the entire development process of this prototype with real-time monitoring with the function of issuing an early fire alert.
Acesso aberto (Open Access)
Sistema embarcado para monitoramento de harpia (Harpia harpyja)
(Universidade Federal do Pará, 2012-07-04) PANTOJA, Breno Ramos; MANTOVANI, Jose Eduardo; http://lattes.cnpq.br/1714283455902751; KLAUTAU JÚNIOR, Aldebaro Barreto da Rocha; http://lattes.cnpq.br/1596629769697284
This Master Thesis consists of an integrated monitoring system for tracking the Harpy Eagle (Harpia harpyja), a species found in Amazon Rainforest, Cerrado and Atlantic Forest. This monitoring system can be divided in three stages: collection, storage and data transmission. The first stage embraces that collection sensors that aim at detecting the presence of birds in the nest, with the support of a camera for video capturing. The second stage executes the data pre-processing and storage. In the third stage, data transmission is performed via the Brazilian System of Ambient Data Collection (SBCDA). This work implemented some of the designed modules, building an incomplete prototype for monitoring. Techniques for embedded systems are also analyzed and the developed detector is evaluated.