- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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The Optical Barcode Detection and Recognition Method Based on Visible Light Communication Using Machine Learning
摘要： Visible light communication (VLC) has developed rapidly in recent years. VLC has the advantages of high confidentiality, low cost, etc. It could be an effective way to connect online to offline (O2O). In this paper, an RGB-LED-ID detection and recognition method based on VLC using machine learning is proposed. Different from traditional encoding and decoding VLC, we develop a new VLC system with a form of modulation and recognition. We create different features for different LEDs to make it an Optical Barcode (OBC) based on a Complementary Metal-Oxide-Semiconductor (CMOS) senor and a pulse-width modulation (PWM) method. The features are extracted using image processing and then support vector machine (SVM) and artificial neural networks (ANN) are introduced into the scheme, which are employed as a classifier. The experimental results show that the proposed method can provide a huge number of unique LED-IDs with a high LED-ID recognition rate and its performance in dark and distant conditions is significantly better than traditional Quick Response (QR) codes. This is the first time the VLC is used in the field of Internet of Things (IoT) and it is an innovative application of RGB-LED to create features. Furthermore, with the development of camera technology, the number of unique LED-IDs and the maximum identifiable distance would increase. Therefore, this scheme can be used as an effective complement to QR codes in the future.
关键词： CMOS image sensor,machine learning,image processing,RGB-LED,visible light communication (VLC)
更新于2025-09-23 15:22:29
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[IEEE 2019 Photonics & Electromagnetics Research Symposium - Fall (PIERS - Fall) - Xiamen, China (2019.12.17-2019.12.20)] 2019 Photonics & Electromagnetics Research Symposium - Fall (PIERS - Fall) - An Intelligent Control System of Music Rhythms by RGB-LED Lamp
摘要： Based on the STM32 single-chip microcomputer (SCM), the relationship between music rhythm and the output color of red-green-blue-light-emitting-diode (RGB-LED) lamp is studied in this paper. Aiming at the problem that music rhythms and colors of light cannot be fully matched, the idea that the colors of RGB-LED lamp are controlled by music rhythms is put forward. Sound collector, microcontroller, power module, bias circuit, and RGB-LED lamp are adopted in the hardware design. In the software, the music data collected by an analog-to-digital converter (ADC) is converted into digital quantities. The color of RGB tricolor is controlled by changing the ratio of pulse width modulation (PWM). With a linear function, we adjust the lighting effect when the rhythm falls and filter out some smaller values, but the improvement is not satisfactory. Therefore, the nonlinear quadratic function instead of the linear function is used to eliminate the flicker when the music rhythm becomes weak. The experimental results show that the proposed improvement can give rise to a much better control effect for the colors of light by the music rhythms.
关键词： STM32,nonlinear function,PWM,music rhythm,RGB-LED
更新于2025-09-19 17:13:59
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[IEEE 2018 IEEE International Conference on Information and Automation for Sustainability (ICIAfS) - Colombo, Sri Lanka (2018.12.21-2018.12.22)] 2018 IEEE International Conference on Information and Automation for Sustainability (ICIAfS) - A Robust Driver for RGB LEDs
摘要： For running applications based on RGB LEDs, a dc-dc buck converter associated with linear control is mostly used to manage the constant current of LED. In this paper, the driver to run RGB LEDs gives 180 mA constant outputs current and a PWM control scheme has been utilized, which determines the desired brightness levels with a dimming frequency of 10000 Hz. Previously there used to be a dimming option for dimming each array of LED color, through the dimming controller circuit; approximately 93%, 90% 93% efficiencies, were found for the green, red and blue color LEDs’ arrays respectively. A digital controller based on PID controller has been created, with the option of using digital dimming by using current mirroring with a transistor (for the intent of switching system). The proposed LED driver system contains the constant source of current to maintain the small drive voltage across the LEDs which lead in the reduction of power dissipation in the transistor, i.e., NPN, which eventually increases the efficiency of the whole system in return. With the application of the 12V supply voltage, the efficiencies of RGB LEDs are found up to 98.94%, 99.37%, and 99.37% correspondingly.
关键词： RGB LED Driver,DC-DC Converter,Digital Controller
更新于2025-09-16 10:30:52
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Study on light aging of anhydride-cured epoxy resin used for RGB LED packaging material
摘要： RGB LED is widely used in white light illumination and display fields due to its high luminous efficiency and full color display. However, the color drift will occur when RGB LED is used for a long time. In this paper, the luminous performance of RGB LED encapsulated by epoxy materials during longtime lighting and the aging mechanism of methyl hexahydrophthalic anhydride (MHHPA) cured diglycidyl ether of bisphenol-A (DGEBA) were studied by Array spectrometer, ATR-FTIR, XPS and quantum-chemistry calculation. Firstly, the analysis of the lumen maintenance and forward voltage of RGB LED lamps showed, the color drift might be attributed to the degradation of its epoxy materials caused by blue light. FTIR Spectroscopy showed that the aging of packaging materials mainly occurred on the surface of blue LED lamps, where active hydrogen of secondary and tertiary carbon might be oxidized to carbonyl groups due to O2 or peroxy groups in the air. And the aging of epoxy materials also might include the chain scission or the rearrangement reactions of C-O-Ph. XPS results further manifested the decrease of C-C group and increase of C-O and C=O group were mainly caused by the chain scission of C-C, C-O-Ph or the ester groups and the oxidation of active hydrogen. And several possible aging reactions were given from the analysis of ATR-FTIR and XPS characterization. The results of quantum-chemistry calculation indicated that C-O bond in C-O-Ph of DGEBA/MHHPA epoxy system was more easily to be broken down during blue light aging, which further verified the results of IR and XPS characterization.
关键词： quantum-chemistry calculation,epoxy resin,light aging,RGB LED
更新于2025-09-16 10:30:52