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Dajian Wang - One of the best experts on this subject based on the ideXlab platform.

Zhiyong Mao - One of the best experts on this subject based on the ideXlab platform.

Jingjing Chen - One of the best experts on this subject based on the ideXlab platform.

Jian Li - One of the best experts on this subject based on the ideXlab platform.

Yong Yang - One of the best experts on this subject based on the ideXlab platform.

  • The performance analysis for lighting sources in highway tunnel based on visual function
    Spectroscopy and Spectral Analysis, 2015
    Co-Authors: Yong Yang, Haifeng Jiang
    Abstract:

    Under the condition of mesopic Vision, the spectral luminous efficiency function is shown as a series of curves. Its peak wavelength and intensity are affected by light spectrum, background brightness and other aspects. The impact of light source to lighting visibility could not be carried out via a single optical parametric characterization. The reaction time of visual cognition is regard as evaluating indexes in this experiment. Under the condition of different speed and luminous environment, testing visual cognition based on Vision function method. The light sources include high pressure sodium, electrodeless fluorescent lamp and white LED with three kinds of color temperature (the range of color temperature is from 1 958 to 5 537 K). The background brightness value is used for basic section of highway tunnel illumination and general outdoor illumination, its range is between 1 and 5 cd x m(-)2. All values are in the scope of mesopic Vision. Test results show that: under the same condition of speed and luminance, the reaction time of visual cognition that corresponding to high color temperature of light source is shorter than it corresponding to low color temperature; the reaction time corresponding to visual target in high speed is shorter than it in low speed. At the end moment, however, the visual angle of target in observer's visual field that corresponding to low speed was larger than it corresponding to high speed. Based on MOVE model, calculating the equivalent luminance of human mesopic Vision, which is on condition of different emission spectrum and background brightness that formed by test lighting sources. Compared with Photopic Vision result, the standard deviation (CV) of time-reaction curve corresponding to equivalent brightness of mesopic Vision is smaller. Under the condition of mesopic Vision, the discrepancy between equivalent brightness of different lighting source and Photopic Vision, that is one of the main reasons for causing the discrepancy of visual recognition. The emission spectrum peak of GaN chip is approximate to the wave length peak of efficiency function in Photopic Vision. The lighting visual effect of write LED in high color temperature is better than it in low color temperature and electrodeless fluorescent lamp. The lighting visual effect of high pressure sodium is weak. Because of its peak value is around the Na+ characteristic spectra. Language: zh

  • The Performance Analysis for Lighting Sources in Highway Tunnel Based on Visual Function
    Guang pu xue yu guang pu fen xi, 2015
    Co-Authors: Yong Yang, Wenyuan Han, Haifeng Jiang, Ming Yan, Liwei Zhu
    Abstract:

    Under the condition of mesopic Vision, the spectral luminous efficiency function is shown as a series of curves. Its peak wavelength and intensity are affected by light spectrum, background brightness and other aspects. The impact of light source to lighting visibility could not be carried out via a single optical parametric characterization. The reaction time of visual cognition is regard as evaluating indexes in this experiment. Under the condition of different speed and luminous environment, testing visual cognition based on Vision function method. The light sources include high pressure sodium, electrodeless fluorescent lamp and white LED with three kinds of color temperature (the range of color temperature is from 1 958 to 5 537 K). The background brightness value is used for basic section of highway tunnel illumination and general outdoor illumination, its range is between 1 and 5 cd x m(-)2. All values are in the scope of mesopic Vision. Test results show that: under the same condition of speed and luminance, the reaction time of visual cognition that corresponding to high color temperature of light source is shorter than it corresponding to low color temperature; the reaction time corresponding to visual target in high speed is shorter than it in low speed. At the end moment, however, the visual angle of target in observer's visual field that corresponding to low speed was larger than it corresponding to high speed. Based on MOVE model, calculating the equivalent luminance of human mesopic Vision, which is on condition of different emission spectrum and background brightness that formed by test lighting sources. Compared with Photopic Vision result, the standard deviation (CV) of time-reaction curve corresponding to equivalent brightness of mesopic Vision is smaller. Under the condition of mesopic Vision, the discrepancy between equivalent brightness of different lighting source and Photopic Vision, that is one of the main reasons for causing the discrepancy of visual recognition. The emission spectrum peak of GaN chip is approximate to the wave length peak of efficiency function in Photopic Vision. The lighting visual effect of write LED in high color temperature is better than it in low color temperature and electrodeless fluorescent lamp. The lighting visual effect of high pressure sodium is weak. Because of its peak value is around the Na+ characteristic spectra.

  • Study on the Highway Tunnel Lighting with Spectrum Superposition
    Advanced Materials Research, 2012
    Co-Authors: Yong Yang, Lei Wang
    Abstract:

    The lighting level of highway tunnel is usually under mesopic Vision condition, but the traditional luminance and illuminance test are corrected by Photopic Vision spectral luminous efficiency. According to the difference of spectral luminous efficiency between Photopic and mesopic, the lighting with different peak wavelength would provide various ratios of radiation / photometric flux. Four kinds of narrowband light sources with the same tested flux were stacked up in white LED and HPS respectively, through equivalent brightness calculation, the most efficient spectral wavelength were obtained under mesopic condition.

  • Equivalent Brightness Fitting Calculation Method about White LEDs
    Applied Mechanics and Materials, 2011
    Co-Authors: Yong Yang, Lei Wang
    Abstract:

    White LEDs can show different correlated color temperature (abbreviated as CCT) by adjusting the luminous spectrum peak distribution and relative strength. Recent research results indicate that spectral luminous efficiency function of mesopic Vision Vmes(λ) and equivalent brightness are associated with luminous spectra of light sources. A series of white LEDs with different CCT are tested and calculated, it shows white LED with higher CCT has higher mesopic Vision equivalent brightness, although the brightness are identical when the tester corrected by traditional Photopic Vision spectral luminous efficiency V(λ). From the equivalent brightness curve fitting, the curve can be described as a polynomial function, for it excellent correlation, the more value of equivalent brightness could be calculated without complex derivation.

  • Highway Tunnel Lighting Research Based on Mesopic Vision
    Applied Mechanics and Materials, 2011
    Co-Authors: Yong Yang, Lei Wang
    Abstract:

    The white LED and high-pressure sodium lamp (HPS) are used to simulate highway tunnel lighting under different background brightness (abbreviated as B) conditions, from a series of reaction time tests, the result shows that white LED can provide shorter reaction time for observers compared with HPS, further research suggests under the mesopic Vision, different kinds of light sources maybe have unlike brightness, although which is identical under the Photopic Vision. From the luminous spectrum test and mesopic Vision spectral luminous efficiency function fitting calculation, the mesopic equivalent brightness can be determined with certain light source and B value. This conclusion would provide a more accurate and lower energy consumption lighting design method for highway tunnel.