An Algorithm to Estimate Thermal Radiance Centre in the Sky Hemisphere for Automotive Solar Sensor Validation

摘要

There is a solar sensor used in vehicles to estimate thermal radiance source position (azimuth and elevation) in the sky hemisphere and the amplitude of irradiance. That data is used for adjusting climate control systems for maximum passengers comfort in vehicle cabin [1]. Producers of such sensors face the absence of standard on what is the position of radiance source in the sky hemisphere. At clear sky conditions, when the sun is at high altitude, the scattered radiance compared to radiance coming directly from the sun is relatively small and can be neglected. But in case of more complex situations, like partly cloudy conditions or low sun altitudes, the scattered radiance part gets significant or dominates [2]. At those circumstances there is no industry definition on what signal output should solar sensors give. That leads to unnecessary misunderstandings between the suppliers of solar sensors and vehicle OEM's. The goal of this research was an attempt to clarify the statement "the position of the radiance source in the sky" by proposing an algorithm to estimate that position.