Light Intensity Sensor Research Articles

Characteristic Analysis Light Intensity Sensor Based On Plastic Optical Fiber At Various Configuration

This research discusses the light intensity sensor based on plastic optical fiber. This light intensity sensor is made of plastic optical fiber consisting of two types, namely which is cladding and without cladding. Plastic optical fiber used multi-mode step-index type made of polymethyl metacrylate (PMMA). The infrared LED emits light into the optical fiber of the plastic and is subsequently received by the phototransistor to be converted to an electric voltage. The sensor configuration is made with three models: straight configuration, U configuration and gamma configuration with cladding and without cladding. The measured light source uses a 30 Watt high power LED with a light intensity of 0 to 10 Klux. The measured light intensity will affect the propagation of light inside the optical fiber sensor. The greater the intensity of the measured light, the greater the output voltage that is read on the computer. The results showed that the best optical fiber sensor characteristics were obtained in U configuration. Sensors with U-configuration without cladding had the best sensitivity and resolution values of 0.0307 volts/Klux and 0.0326 Klux. The advantages of this measuring light intensity based on the plastic optical fiber instrument are simple, easy-to-make operational systems, low cost, high sensitivity and resolution.

WSNs heterogeneous cluster routing based on distributed fuzzy logic inference

In this paper, the wireless sensor network of heterogeneous non-uniform distribution is studied, and sun energy harvesting model ISHE based on intensity of illumination is proposed. In ISHE model, the light intensity sensor is used to read solar illuminance under the current environment, and then, energy size obtained by solar energy supply node at specified period can be estimated based on corresponding relation between illuminance and irradiance. The experiment results show that invalidation round rate of the first node LEACH in the algorithm proposed in the paper is 86.2% higher than the average value and invalidation round rate of the last node is 65.9% higher than the average value; network coverage rate of the algorithm in 86% of lifetime is 38% higher than LEACH; network throughput of the algorithm proposed in the thesis at round 2,000 is five times as that of LEACH.

WSNs heterogeneous cluster routing based on distributed fuzzy logic inference

In this paper, the wireless sensor network of heterogeneous non-uniform distribution is studied, and sun energy harvesting model ISHE based on intensity of illumination is proposed. In ISHE model, the light intensity sensor is used to read solar illuminance under the current environment, and then, energy size obtained by solar energy supply node at specified period can be estimated based on corresponding relation between illuminance and irradiance. The experiment results show that invalidation round rate of the first node LEACH in the algorithm proposed in the paper is 86.2% higher than the average value and invalidation round rate of the last node is 65.9% higher than the average value; network coverage rate of the algorithm in 86% of lifetime is 38% higher than LEACH; network throughput of the algorithm proposed in the thesis at round 2,000 is five times as that of LEACH.

Design of Wireless Sensor Network Bidirectional Nodes for Intelligent Monitoring System of Micro-irrigation in Litchi Orchards

Wireless sensor network (WSN) bidirectional nodes, including the sensing node and the solenoid valve control node, were developed for information collection and micro-irrigation monitoring system in a litchi orchard, aimed at improving the problem of wireless communication barriers and the micro-irrigation management efficiency. The sensing node was composed of an MCU8051, a CC2530 RF chip for communication, a RFX2401for amplification. This node is supposed to collect data from a DHT22 air temperature and humidity sensor, a GY-30 light intensity sensor and a TDR-3 soil moisture sensor. The control node includes an MCU8051, a CC2530 RF chip for communication, and peripheral drive circuits for adapting the bi-stable pulse solenoid valve. The application software and backstage management software were written with these two nodes as the hardware platform, based on ZStack agreement. The maximum effective bidirectional communication distance of the designed nodes reached 1205m in unoccupied regions and 122m in litchi orchards. Within a 30 min working cycle, it could be estimated that two 3.7 V battery with a rated capacity of 3000 mA•h can power the sensing node for time up to 500d. Test results in litchi orchards show that the average packet loss rate is 0.75%. The system was processing smoothly with the above nodes for information acquisition and controlling micro-irrigation in litchi orchards.

Photoreaction of BlrP1: the role of a nonlinear photo-intensity sensor.

Blue-light-regulated phosphodiesterase 1 (BlrP1) is a blue light sensor protein that controls the hydrolysis of cyclic dimeric guanosine monophosphate, which regulates cellular motility, virulence, and formation of biofilms. In this report, the photoreaction dynamics of BlrP1 and its blue light sensor using a flavin adenine dinucleotide (BLUF) domain were investigated by the time-resolved transient grating method. Only a minor conformational change of the BlrP1-BLUF domain was observed. In contrast, a significant conformational change of the full-length BlrP1 was detected as a diffusion change with a time constant of 21 ms. Interestingly, the extent of the conformational change was concentration-dependent and the dimer form of BlrP1 was found to be the species that exhibited the conformational change. In combination with circular dichroic measurements, a quaternary structural change was determined to be the main origin of the diffusion change. Surprisingly, this conformational change was found to depend strongly on the excitation light intensity. This light-intensity-dependence indicates that the conformational change is induced by the photoexcitation of two monomer units of the dimer. The results suggest that BlrP1 is not only a photosensor but also a light intensity sensor possessing a nonlinear response.

The photocycle of orange carotenoid protein conceals distinct intermediates and asynchronous changes in the carotenoid and protein components

The 35-kDa Orange Carotenoid Protein (OCP) is responsible for photoprotection in cyanobacteria. It acts as a light intensity sensor and efficient quencher of phycobilisome excitation. Photoactivation triggers large-scale conformational rearrangements to convert OCP from the orange OCPO state to the red active signaling state, OCPR, as demonstrated by various structural methods. Such rearrangements imply a complete, yet reversible separation of structural domains and translocation of the carotenoid. Recently, dynamic crystallography of OCPO suggested the existence of photocycle intermediates with small-scale rearrangements that may trigger further transitions. In this study, we took advantage of single 7 ns laser pulses to study carotenoid absorption transients in OCP on the time-scale from 100 ns to 10 s, which allowed us to detect a red intermediate state preceding the red signaling state, OCPR. In addition, time-resolved fluorescence spectroscopy and the assignment of carotenoid-induced quenching of different tryptophan residues derived thereof revealed a novel orange intermediate state, which appears during the relaxation of photoactivated OCPR to OCPO. Our results show asynchronous changes between the carotenoid- and protein-associated kinetic components in a refined mechanistic model of the OCP photocycle, but also introduce new kinetic signatures for future studies of OCP photoactivity and photoprotection.

Personalized cumulative UV tracking on mobiles & wearables.

Maintaining a balanced Ultra Violet (UV) exposure level is vital for a healthy living as the excess of UV dose can lead to critical diseases such as skin cancer while the absence can cause vitamin D deficiency which has recently been linked to onset of cardiac abnormalities. Here, we propose a personalized cumulative UV dose (CUVD) estimation system for smartwatch and smartphone devices having the following novelty factors; (a) sensor orientation invariant measurement of UV exposure using a bootstrap resampling technique, (b) estimation of UV exposure using only light intensity (lux) sensor (c) optimal UV exposure dose estimation. Our proposed method will eliminate the need for a dedicated UV sensor thus widen the user base of the proposed solution, render it unobtrusive by eliminating the critical requirement of orienting the device in a direction facing the sun. The system is implemented on android mobile platform and validated on 1200 minutes of lux and UV index (UVI) data collected across several days covering morning to evening time frames. The result shows very impressive final UVI estimation accuracy. We believe our proposed solution will enable the future wearable and smartphone users to obtain a seamless personalized UV exposure dose across a day paving a way for simple yet very useful recommendations such as right skin protective measure for reducing risk factors of long term UV exposure related diseases like skin cancer and, cardiac abnormality.

A Monitoring System of Battery LiFePO4 for Assessment Stand-Alone Street Light Photovoltaic System Based on LabVIEW Interface for Arduino

The paper presents monitoring and assessment system of battery LiFePO<sub>4</sub> performance that applied on a stand-alone photovoltaic system. A stand-alone photovoltaic system is constructed by photovoltaic module 50 Watt Peak, Pulse Width Modulation solar controller, battery module LiFePO<sub>4</sub> battery (12 Volt 21 Ah), and street light 10 watt. To overcome the data acquisition, a simple monitoring system has been designed using LabVIEW Interface for Arduino. The voltage divider, current sensing type ACS712, temperature and humidity sensor, and light intensity sensor were used to collect the data. The data processed by a dual microcontroller (ATmega-2560 and ATmega-328) and LabVIEW software on Personal Computer. The assessment of stand-alone photovoltaic system includes battery LiFePO<sub>4</sub> performance (State of Charge, voltage, and current) during charging and discharge condition, the power efficiency, and environmental condition (temperature, humidity and solar radiation). In the discharge condition, voltage battery and State of Charge decreased about 40% after 12 hours operated. In the charge condition, the current battery fluctuated in the range of 0.10 A-1.95 A and the State of Charge increased up to 25% after 8 hours operated. It indicates that the power of the battery has always lacked.

Sistem Atap Rumah Otomatis pada Smarthome dengan Menggunakan Arduino

Development of Smarthome system has many important contributions to make a comfortable house. One of the problems is how to keep the house comfortable without becoming moist and getting enough sunlight. In this study, the roof opening that can automatically provide the supply of sunlight using automated roof opener. Manual control of the tool is using smartphone application that communicates through a Bluetooth HC-05 module. This tool also uses an automatic controller with a raindrop sensor that automatically activated when the rain drops on the sensor panel. In addition, this system also integrates the automatic light-intensity sensor using LDR (Light Dependent Resistor). The result of whole system testing is automatic rooftop opener using Arduino Uno works perfectly as the design that the motor is able to be controlled by smartphone application using serial communication based on Bluetooth so that the rooftop can be opened and closed. Pembuka atap otomatis dikembangkan dengan mengunakan mikrokontroler Arduino uno. Kontrol manual dari alat ini dilakukan dengan menggunakan aplikasi smartphone yang secara otomatis dan serial berkomunikasi dengan modul bluetooth HC-05. Alat ini juga menggunakan pengendali otomatis dengan sensor rintik hujan yang diaktifkan secara otomatis bila tetes hujan menyentuh panel sensor. Selain itu, sistem ini juga mengintegrasikan sensor cahaya intensitas otomatis menggunakan LDR (Light Dependent Resistor). Hasil pengujian sistem secara keseluruhan adalah pembuka atap otomatis menggunakan uno Arduino bekerja sempurna sebagai perencanaan bahwa motor ini mampu dikontrol oleh aplikasi smarthome dengan mengunakan komunikasi bluetooth, sehingga atap dapat terbuka dan tertutup pada titik tertentu.

Desarrollo de un Sistema de Iluminación Artificial Inteligente para Cultivos Protegidos

This article describes the hardware and software development of an artificial lighting system for protected crops. The system consists of a set of lamps, power control circuits and light intensity sensor, which together with a software developed in LabVIEW® allow to carry out the control over the amount of energy radiated throughout the cultivation process taking into consideration how this energy is distributed in each photoperiod. All this monitoring process takes place in a computer which is connected to an Arduino MEGA device serves as data acquisition card. To program the operation of the control system an interface is designed that enables the user to input parameters and display the system operating information. It also allows selecting the appropriate control strategy with a choice of selecting a predictive control or PD control system. Both algorithms make use of a mathematical model of the lamps which is responsible for transforming the signals generated by the drivers in digital signals that govern the operation of the implemented electronic system. Finally, the experimental results are analysed in various tests using both control algorithms to show the benefits and disadvantages of each controller.

A Photodetector Based on a Conjugated Polymer and PbS Colloidal Quantum Dots

This work presents the development of a light intensity sensor based using colloidal PbS quantum dots. A simple fabrication method at low cost makes the developed sensor suitable for light detection applications. Photodetectors based on quantum dots have various advantages compared to solid-state photodetectors. The reported advantages include ease of fabrication, narrow and tunable spectral response, large sensing area, reduced dark current, and high sensitivity [1, 2]. Solution-based fabrication makes the whole process simple and cost efficient. The structure of the sensor in this work is shown in the figure having a light sensitive composite sandwiched by two electrodes of which one is usually a transparent electrode made of indium tin oxide (ITO). For validation, we employed PbS colloidal quantum dots and poly(2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene) or MEH-PPV to form the light sensitive composite [3]. In the light sensitive composite, a charge separation occurs by a photon generating a neutral exciton at the interface of the conjugated polymer and the quantum dots. We started with an ITO coated glass substrate. The light sensitive composite made of MEH-PPV and colloidal quantum dots was then cast on top by spin coating. For the other electric contact, an aluminum layer was deposited by physical vapor deposition. The fabricated photodetector shows a promising sensitivity to incident light, and further characterization is currently underway. Since the entire structure of the photodetector is simple and the entire process can be done with low thermal budget, the photodetector can also be formed on a flexible substrate.

Development and implementation of control-oriented models for terminal heating and cooling units

Two control-oriented models that can predict the temperature of a perimeter office space were developed by using the data gathered from light intensity, motion and temperature sensors, and terminal heating and cooling units. One model had five unknown parameters while the second had ten unknown parameters and an immeasurable state. The models’ parameters were estimated in recursion by employing the Extended Kalman Filter. The appropriateness of the models to the dataset was analyzed through a residual analysis, and the predictive accuracy of the models was contrasted. Both models could make offline predictions over a two day horizon at less than 0.75°C mean absolute error. It was concluded that the one-state model was able to mimic the temperature response of small perimeter office spaces parsimoniously. The one-state model was implemented inside four building controllers serving eight private office spaces. In tandem with Gunay et al. [1]’s occupancy-learning algorithm, the one-state model was employed to determine optimal start and stop times for the temperature setback periods. Results of this implementation indicated that the duration of the weekday temperature setback periods could be increased more than 50% for both heating and cooling—in contrast to the default control scheme. EnergyPlus simulation results suggest that this accounts for about 30% reduction in heating and 13% reduction in cooling loads without affecting the indoor air temperature during occupied periods.

Artificial Versus Natural Light Source Identification with Light Intensity Sensors for Energy Monitoring

Studies have shown that increasing the granularity of energy consumption information in buildings could facilitate achieving energy saving objectives. Lighting systems in buildings are one of the main consumers of electricity with a share of approximately (direct and indirect) 23 percent of the total electricity in the US. Direct monitoring of lighting systems is not feasible due to challenges for instrumentation. In this study, we are proposing an approach for monitoring of lighting systems energy consumption by using single light intensity sensors. Load monitoring through light sensors is challenging due to the contribution of natural light in variation of the signal magnitude in the captured time series. Accordingly, we have proposed a new feature in frequency domain that helps us identify artificial light (AL) source type and improve AL event detection. Field experimental study showed the effectiveness of the proposed feature by eliminating all false positives in event detection.

AUTOMATIC HEADLIGHT BEAM INTENSITY SWITCHER

The evolution in the technology of automobiles has reached its peak. One of the most innovative features is the invention of driver less car or an autonomous car. An autonomous car controls the motion, sensor activation and action automatically without any human intervention. Such vehicles ensure high degree of safety, comfort and ease of driving. The project aims at designing a system to be used in such autonomous cars. The project is to develop an automatic headlight beam intensity switcher. Such a system will sense the beam status of opposing vehicle and switch the beam intensity of headlight. A sensor based mechanism is utilized to develop the system. The beam intensity switcher plays a very important role while driving. During night time, when two vehicles approach each other in opposite direction the high intensity headlight creates an effect called “Troxler effect”. This effect creates a temporary blindness for some seconds thus resulting in unfortunate accidents. Thus, the high beam of both the vehicles must be switched to low so as to have a comfortable driving. The use of such a device in cars can prevent accidents at night time due to driver inattentiveness and provides an ease of driving. We have used the Arduino UNO board as our microcontroller and application specific sensors. In our project we have designed a device which is a combination of software and hardware coding. The sensor used is a light intensity sensor named BH1750 which has a wide range of sensing capacity. The light sensor takes the “lux ” reading of the headlight rays from the opposing vehicle and checks for a threshold value assigned in the coding. Based on the threshold value the beam switches from high to low state and vice-versa when both the vehicles pass by each other. The same process takes place in opposite vehicle too. This device can be implanted on the front part of the car at an appropriate position and angle.

The Research and Design of the Adaptive Automotive Headlamps Based LED System

A new control scheme with self-adaption is put forward in this paper. The digital control and the analog circuit are combined. A light intensity sensor can be implemented with a photoelectric triode. This sensor makes the self-adaptation control of LED possible. As a result, the light of LED can be adjusted automatically with a PWM chopper according to the ambient brightness. The whole system’s power supply is from a Boost converter which has a high efficiency. In addition, This combination improves the hommization of the system and solves the problems existing incurrent headlamps, unsafe factors are also reduced. The validity of design is verified by experimental results.

Light Intensity Sensor Based on an Azo-Infiltrated Microstructured Optical Fiber

The photoisomerization effect of the azo functional material is introduced into a solid-core microstructured optical fiber (MOF) by infiltrating the N-Ethyl-N-(2-hydroxyethyl)-4-(4-nitrophenylazo) aniline (Disperse Red 1)-chloroform mixture solution into its cladding air holes. The irradiation laser power density as well as temperature effects on the transmission spectral characteristics of the solution-infiltrated MOF have been investigated. Owing to its highly sensitive light responsivity, ease of manipulation, and compactness, our proposed photosensitization approach for fiber-optic devices would have great promises for various related applications, such as light-intensity measurement and light-driven reconfigurable optical filtering.

A Hemispherical Sun Sensor for Orientation and Geolocation

We propose a novel sensing system with a hemispherical arrangement of light intensity sensors to determine the vector to the dominant light source in its environment. We apply this system to the measurement of sun vector. The accuracy of our sensor is proved to be scalable when using more sensing pixels. Our experimental data yields the solar azimuth to within 5° and the solar zenith to within 1° using only five light intensity sensors. A sensor operation procedure is provided to improve sensor accuracy. A method is shown that determines absolute orientation and location from the measured sun vector. The corresponding uncertainty analysis is also presented.

Design of a Simulating Control System for Hybrid Wind/PV Power Generation

A system based on STM32F103 chip is designed to simulate the hybrid wind and PV wind power generation control process. The simulation system consists an electric motor with stepless rotational speed regulating feature to simulate wind turbine power generation, a light intensity sensor to simulate PV power generation with its measure results, the electrical source of chip microcomputer to simulate the current output from storage batteries, and two electric motors with different power to simulate the direct-current loads. The control strategy and the corresponding programs are developed based on certain hardware composition and the control system is implemented and operates well.

Modulating energy arriving at photochemical reaction centers: orange carotenoid protein-related photoprotection and state transitions.

Photosynthetic organisms tightly regulate the energy arriving to the reaction centers in order to avoid photodamage or imbalance between the photosystems. To this purpose, cyanobacteria have developed mechanisms involving relatively rapid (seconds to minutes) changes in the photosynthetic apparatus. In this review, two of these processes will be described: orange carotenoid protein(OCP)-related photoprotection and state transitions which optimize energy distribution between the two photosystems. The photoactive OCP is a light intensity sensor and an energy dissipater. Photoactivation depends on light intensity and only the red-active OCP form, by interacting with phycobilisome cores, increases thermal energy dissipation at the level of the antenna. A second protein, the "fluorescence recovery protein", is needed to recover full antenna capacity under low light conditions. This protein accelerates OCP conversion to the inactive orange form and plays a role in dislodging the red OCP protein from the phycobilisome. The mechanism of state transitions is still controversial. Changes in the redox state of the plastoquinone pool induce movement of phycobilisomes and/or photosystems leading to redistribution of energy absorbed by phycobilisomes between PSII and PSI and/or to changes in excitation energy spillover between photosystems. The different steps going from the induction of redox changes to movement of phycobilisomes or photosystems remain to be elucidated.

Collector Design of Tracking System Based on PLC

This article describes the Parabolic trough solar collector design of single-axis tracking system based on PLC, Siemens S7-300 as a controller, using a complex mathematical model, based on the special climate of Western Region, select the single-axis design process, greatly reduced cost, collectors need only be completed that automatically tracks the sun azimuth. Feedback device selection angle sensor, light intensity sensor and sun sensor, strain two conditions that cloudy and sunny, which greatly improves the efficiency of the collector, the better to achieve real-time tracking grasp the situation.