scholarly journals Passive Visible Light Detection of Humans

Sensors ◽  
2020 ◽  
Vol 20 (7) ◽  
pp. 1902 ◽  
Author(s):  
Kenneth Deprez ◽  
Sander Bastiaens ◽  
Luc Martens ◽  
Wout Joseph ◽  
David Plets
Keyword(s):  
Visible Light ◽  
Detection Rate ◽  
Detection System ◽  
Light Emitting Diode ◽  
Line Of Sight ◽  
Controlled Environment ◽  
Ambient Light ◽  
Light Emitting ◽  
Light Sensing ◽  
Reflected Light

This paper experimentally investigates passive human visible light sensing (VLS). A passive VLS system is tested consisting of one light emitting diode (LED) and one photodiode-based receiver, both ceiling-mounted. There is no line of sight between the LED and the receiver, so only reflected light can be considered. The influence of a human is investigated based on the received signal strength (RSS) values of the reflections of ambient light at the photodiode. Depending on the situation, this influence can reach up to ± 50 % . The experimental results show the influence of three various clothing colors, four different walking directions and four different layouts. Based on the obtained results, a human pass-by detection system is proposed and tested. The system achieves a detection rate of 100% in a controlled environment for 21 experiments. For a realistic corridor experiment, the system keeps its detection rate of 100% for 19 experiments.

scholarly journals Integrated Light Sensing and Communication for LED Lighting

Designs ◽  
2018 ◽  
Vol 2 (4) ◽  
pp. 49 ◽  
Author(s):  
Massimo Ruo Roch ◽  
Maurizio Martina
Keyword(s):  
Light Emitting Diode ◽  
Low Cost ◽  
Solid State Lighting ◽  
High Flux ◽  
Ambient Light ◽  
Light Emitting ◽  
Industrial Environment ◽  
Led Lighting ◽  
Light Sensing ◽  
Visual Light

Solid state lighting is nowadays widely diffused both in residential and office or industrial environment. Ambient light sensing to modulate lamp power is typical too, but sensors inside a lamp are a challenge, due to the high flux of these sources, which easily saturates nearby light detectors. Usually, separate sensing devices must be introduced in the system, thus increasing complexity and cost. In this work, a methodology will be presented, to allow integration of a light sensing device inside a lamp, using low cost circuitry to mitigate interactions between high power light-emitting diode (LED) sources and sensing photodiodes. Moreover, the same circuit allows visual light communication among sources.

An approach to ensure joint illumination & communication performance of a forward error corrected indoor visible light communication (VLC) system in presence of ambient light interference

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Sourish Chatterjee ◽  
Biswanath Roy
Keyword(s):  
Visible Light ◽  
Bit Error Rate ◽  
Error Rate ◽  
Light Emitting Diode ◽  
Visible Light Communication ◽  
Ambient Light ◽  
Ambient Illumination ◽  
Communication Performance ◽  
Light Interference ◽  
Forward Error

AbstractIn recent time of looming radio frequency (RF) spectrum crisis, visible light communication using lighting infrastructure emerged as a potential alternative at an indoor environment. This paper addresses the setback associated with ambient light interference in an indoor Visible Light Communication (VLC) system to ensure joint communication and illumination performance inside an office room. A novel VLC architecture with suitable white light emitting diode (WLED) luminaire arrangement is presented to minimize the dispersion of signal to interference plus noise ratio (SINR) across the room. Luminaires are categorized in two groups viz. data transmitting illuminants and illuminants for lighting purpose. The first group is dedicated to transmit data as well as serves the purpose of illumination. The other set creates only ambient illumination to achieve quality lighting attributes. The proposed forward error corrected receiver configuration discards the ambient light noise originated by the illuminants that serve the ambient illumination. Tail biting convolutional encoder and viterbi decoder are used at the encoding section of the transmitter and decoding section of the receiver respectively to improve bit error rate. Results obtained through MATLAB simulation shows better average bit error rate (BER) in the order of 10−8 measured at uniformly distributed 25 grid points over the working plane. At the same time achieved average horizontal illuminance with good uniformity comply with ISO recommendation.

The Intellectual Lighting And Data Transmission System based On RGBW Light Emitting Diodes

2021 ◽  
pp. 63-68
Author(s):  
Daniil S. Shiryaev ◽  
Olga A. Kozyreva ◽  
Ivan S. Polukhin ◽  
Sergey A. Shcheglov ◽  
Svetlana A. Degtiareva ◽  
...  
Keyword(s):  
Visible Light ◽  
Data Transmission ◽  
Light Transmission ◽  
Transmission Rate ◽  
Light Emitting Diode ◽  
Spectral Characteristics ◽  
System Component ◽  
Transmission Channel ◽  
Error Vector Magnitude ◽  
Light Emitting

The system of intellectual lighting data transmission via visible light is developed and manufactured. Spectral characteristics of a downlink which uses the red crystal of a RGBW light emitting diode for data transfer were studied. The DALI protocol-based radiation chromaticity control system which allows us to set different lighting scenarios with constant data transmission rate was developed. The radiation chromaticity range covers almost the entire colour gamut in the colour space. The system of high-frequency matching of system component impedances was developed and frequency characteristics of the suggested scheme were studied for development of the system. Optimal parameters of the signal for visual light communication such as carrier frequency, modulation type and band were determined. Observation of the constellation diagram which represents different values of the complex amplitude of the keyed signal in the form of a complex number on a quadrature plane (cosine and sine components of the carrying signal) and of fixation of the amplitude of the error vector magnitude (EVM) was selected as a method of study of the transmission channel quality. The value of EVM in the visible light transmission channel was significantly lower for signals with amplitude modulation than for phase-manipulated signals. When implementing different lighting change scenarios, radiation of other crystals of the light emitting diode crystals not used for transmission did not lead to increase of EVM by more than one percent.

scholarly journals Penyuluhan Alat Deteksi Kesadahan Dalam Air Berbasis Light Dependent Resistor Di Kelurahan Giritontro, Kecamatan Giritontro, Kabupaten Wonogiri

2018 ◽  
Vol 2 (2) ◽  
pp. 95-99
Author(s):  
Sumarna Sumarna ◽  
Dyah Kurniawati Agustikasa ◽  
Agus Purwanto ◽  
Nur Kadarisman ◽  
Anggiyani Ratnaningtyas Eka Nugraheni ◽  
...  
Keyword(s):  
Kidney Disease ◽  
Community Service ◽  
Detection System ◽  
Light Emitting Diode ◽  
Water Hardness ◽  
Natural Sciences ◽  
State University ◽  
Light Emitting ◽  
Light Passing ◽  
Service Activity

Beberapa daerah di Wonogiri memiliki tanah yang mengandung kapur, sementara itu sebagian masyarakat mengonsumsi air yang berasal dari dalam tanah. Pada kegiatan pengabdian kepada masyarakat tahun 2016 ditemukan permasalahan dalam masyarakat di kelurahan Wonogiri yaitu sulitnya mendeteksi adanya kapur dalam air yang mereka konsumsi. Sebagai akibatnya banyak masyarakat yang menderita penyakit dalam yang diakibatkan pengendapan kapur di dalam tubuh mereka seperti penyakit ginjal. Oleh karenanya, tim PPM Fakultas MIPA Universitas Negeri Yogyakarta membangun sistem pendeteksi adanya kapur dalam cairan berbasis Light Emitting Diode (LED) dan Light Dependent Resistor (LDR). LED digunakan untuk menyinari cairan dengan kadar kapur yang berbeda-beda, kemudian LDR akan mendeteksi cahaya LED yang melewati cairan tersebut. Besar kecilnya nilai luaran LDR akan bergantung kadar kapur dalam cairan. Masyarakat sangat antusias dan mulai menggunakan alat ini untuk mendeteksi adanya kapur di air yang mereka konsumsi. Kata kunci: Kesadahan, LDR, LED Workshop On Detector of Water Hardness Based On Light Dependet Resistor In Giritontro Village, Giritontro District, Wonogiri RegencyAbstract           Some areas in Wonogiri contain hardness in its soil, while some people consume water that come from the soil. In community service activity in 2016, we found problems in the community in Giritontro, Wonogiri that is the difficulties to detect the hardness in the water that people consume. As a result, many people who suffer from internal diseases caused by the deposition of lime in their bodies such as kidney disease. Therefore, the PPM team of the Faculty of Mathematics and Natural Sciences of Yogyakarta State University built a hardness detection system in liquid based Light Emitting Diode (LED) and Light Dependent Resistor (LDR). LEDs are used to irradiate fluids with different lime levels, then LDR will detect the LED light passing through the liquid. The size of the LDR output value will depend on the lime content in the liquid. People are very enthusiastic and start using this tool to detect the presence of limestone in the water they consume. Keywords: Hardness, LDR, LED

Reduction of Reflected Light On Fluorescence Emission for Indocyanine Green

2021 ◽  
Author(s):  
So Yoon Kwon ◽  
Ki-Cheol Yoon ◽  
Kwang Gi Kim
Keyword(s):  
Blood Vessel ◽  
Indocyanine Green ◽  
Blood Vessels ◽  
Light Emitting Diode ◽  
Polarized Light ◽  
Fluorescence Emission ◽  
Light Reflection ◽  
Light Emitting ◽  
Surgical Microscope ◽  
Reflected Light

Abstract Inside the brain tumor, the blood vessels are intricately composed, and the tumors and blood vessels are similar in color. Therefore, when observing tumors and blood vessels with the naked eye or a surgical microscope, it is difficult to distinguish between tumors and blood vessels. Fluorescence staining with indocyanine green (ICG) is performed to distinguish between brain tumors and blood vessels using a surgical microscope. However, when observing the blood circulation state of a tumor or blood vessel through a surgical microscope, light reflection occurs from the camera. In the process of observing the state of the blood vessel, due to the occurrence of light reflection, an obstruction phenomenon in which the observation field is blocked by the blood vessel of the object to be observed occurs. Therefore, it is difficult to diagnose the vascular condition. In this experiment, the 780nm light-emitting diode (LED) was irradiated to the ICG phantom, and then, when the fluorescence expression image was observed, the polarizing filter such as circular polarized light (CPL) filter and linear polarized light (LPL) filter were inserted into the camera and the reflected light was reduced. Therefore, it is possible to reduce the reflected light from the fluorescence expression image by using a polarizing filter, and it is expected to be applicable to surgery and diagnostic fields of cancer such as surgery.

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