Infrared presence sensing with modeled background subtraction

摘要

A motion sensing device includes an infrared radiation (IR) sensor configured receive signal IR from a warm object and background IR to produce a direct current output. A first transformation filter receives the direct current output and produces a filtered background. A second transformation filter receives the direct current output and produces a filtered signal. A rating compares the filtered signal and the filtered background to produce a result signal based on a detected difference between the filtered signal and the filtered background.