Smart Natural Space Research Center, Kongju National University, Cheonan 31080, Korea.
Department of Computer Science & Engineering, Kongju National University, Cheonan 31080, Korea.
Sensors (Basel). 2020 Nov 18;20(22):6603. doi: 10.3390/s20226603.
The characteristics of natural light are mostly collected through specialized measuring equipment, such as a spectroradiometer, and some suggested measurement methods through a small RGB sensor. However, specialized measuring equipment presents difficulty in its high cost, and the RGB-sensor-based method has the limitation of being unable to measure the wavelength characteristics of natural light that are needed to implement lighting that supports circadian rhythms. This paper presents a method for calculating the short-wavelength-ratio-based color temperature of natural light in real time. First, an analysis of the correlation between the characteristics of natural light collected through a spectroradiometer was performed to determine the factors that were needed to accurately measure the color temperature of natural light. Then, the short-wavelength ratio of natural light was calculated through chromaticity coordinates (x and y), which are output values of the RGB sensor, and an equation for calculating the color temperature of natural light was derived through the short-wavelength ratio. Furthermore, after producing an RGB-sensor-based device, the derived equation was applied to calculate the color temperature of real-time natural light that reflects the wavelength characteristics. Then, as a result of the performance evaluation of the proposed method, the color temperature of natural light was accurately calculated within 1% of the average error rate.
自然光的特性主要通过光谱辐射计等专业测量设备进行收集，也可以通过小尺寸的 RGB 传感器建议一些测量方法。但是，专业的测量设备存在成本高的问题，而基于 RGB 传感器的方法则无法测量自然光的波长特性，这些特性是实现支持昼夜节律的照明所必需的。本文提出了一种实时计算自然光短波比值基色温度的方法。首先，通过分析光谱辐射计采集的自然光特性之间的相关性，确定了准确测量自然光色温度所需的因素。然后，通过 RGB 传感器输出值的色度坐标（x 和 y）计算自然光的短波比值，并通过短波比值推导出自然光色温度的计算公式。此外，在制作基于 RGB 传感器的设备之后，将推导的公式应用于计算实时自然光的色温度，以反映自然光的波长特性。然后，通过对所提出方法的性能评估，自然光的色温度可以在平均误差率 1%的范围内准确计算。
