Development of a visible light transmission (VLT) measurement system using an open-path optical method

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.

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Experimental study of saturation by visible light transmission in dual-scale fibrous reinforcements during composite manufacturing

Journal of Reinforced Plastics and Composites ◽

10.1177/0731684417725187 ◽

2017 ◽

Vol 36 (23) ◽

pp. 1693-1711 ◽

Cited By ~ 4

Author(s):

F LeBel ◽

É Ruiz ◽

F Trochu

Keyword(s):

Visible Light ◽

Light Transmission ◽

Void Formation ◽

In Situ Monitoring ◽

Injection System ◽

Computer Assisted ◽

Liquid Composite Molding ◽

Composite Molding ◽

The Impact ◽

Dual Scale

A new in situ monitoring strategy is proposed to study void formation during real-time impregnation of dual-scale fibrous reinforcements in liquid composite molding. Void content data from burn-off tests are used to calibrate a refractive index matching approach based on two optical principles: Beer–Lambert and Fresnel laws. Once calibrated, this approach based on visible light transmission is used to study the impact of key process parameters on the saturation footprint of dual-scale fibrous reinforcements during and after mold filling. The injection parameters investigated are the flow front velocity, the pressure distribution inside the mold cavity, the bleeding flow rate, and the mold packing pressure. The experimental setup is a computer-assisted injection system and a transparent resin transfer molding mold is used to perform unidirectional injections. A vinyl ester resin is injected through E-glass bidirectional non-crimp fabrics under various manufacturing conditions. This investigation not only confirms the decreasing trend in void formation by mechanical entrapment of air with the decrease in impregnation velocity, as it converges toward the optimal impregnation conditions for this fibrous reinforcement reported in previous studies, but it also brings insights on void dissolution and transport in liquid composite molding.

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Sistem Komunikasi Suara Bawah Air dengan Metoda Simplex menggunakan Visible Light Communication (VLC)

ELKOMIKA Jurnal Teknik Energi Elektrik Teknik Telekomunikasi & Teknik Elektronika ◽

10.26760/elkomika.v7i2.253 ◽

2019 ◽

Vol 7 (2) ◽

pp. 253

Author(s):

LUCIA JAMBOLA ◽

ARSYAD RAMADHAN DARLIS ◽

LITA LIDYAWATI ◽

DZIKRI FACHRI HUSAENI

Keyword(s):

Visible Light ◽

Communication Systems ◽

Light Transmission ◽

Visible Light Communication ◽

Color Filter ◽

Underwater Communication ◽

Test Results ◽

Voice Communication ◽

Yellow Color ◽

Long Time

ABSTRAKSistem komunikasi suara bawah air telah dikenal sejak lama, diantaranya sonar dan akustik. Seiring perkembangan zaman dan kemajuan teknologi, kini hadir komunikasi dengan media transmisi cahaya tampak yaitu Visible Light Communication (VLC) yang dapat diterapkan pada komunikasi bawah air. Pada penelitian ini telah dilakukan komunikasi suara bawah air (simplex) menggunakan VLC, dengan media akuarium berisi air dan beberapa pengujian diantaranya menggunakan color filter, didapat hasil pengujian terbaik yaitu tegangan 4,4 Vpp dan frekuensi 3,003 kHz untuk color filter yellow, pengujian menggunakan lensa didapat hasil pengujian terbaik yaitu tegangan 4,4 Vp-p dan frekuensi 3,051 kHz untuk lensa (+50), dan pengujian terakhir menggunakan lampu UV didapat hasil pengujian terbaik dengan tegangan 4,4 Vp-p dan frekuensi 3,010 kHz. Implementasi sistem VLC ini menunjukkan hasil yang baik dan layak untuk diterapkan pada komunikasi suara bawah air (simplex).Kata kunci: VLC, Komunikasi Suara Bawah Air, Simplex. ABSTRACTUnderwater voice communication systems have been known for a long time, including sonar and acoustics. Along with the development and advancement of technology, now there is communication with visible light transmission media, namely Visible Light Communication (VLC) which can be applied to underwater communication. Under this study underwater voice communication (simplex) has been carried out using VLC, with aquarium media containing water and several tests including using a color filter, the best test results obtained are voltage 4.4 Vp-p and frequency 3.003 kHz for yellow color filter, testing using the lens obtained the best test results namely voltage 4.4 Vp-p and frequency 3.051 kHz for lenses (+50), and the last test using UV lights obtained the best test results with a voltage of 4.4 Vp-p and a frequency of 3.010 kHz. The implementation of the VLC system shows good and feasible results to be applied to underwater voice communication (simplex).Keywords: VLC, Underwater Voice Communication, Simplex.

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