Estimation of the Person's Position Using Video Sequences and Radio Wave Strengths in a Space with Temporary Shielding

The video sequence acquired from the camera can be used to estimate a person's position accurately. We need to pay attention to the fact that the camera does not estimate the person's position when the camera's field of view is unavoidably blocked by temporary shielding. In recent years, several methods have been proposed to estimate the person's position using radio waves, which emit a wavelength longer than that of visible light and are unaffected by shielding. However, collecting training samples consisting of pairs of the radio wave strength and the person's position is difficult because the radio wave strength acquired from wireless devices cannot be intuitively annotated by humans like the video sequences acquired from the camera. We propose a method for estimating the person's position, even temporarily shielded, by combining the camera and the wireless devices. Specifically, our method automatically collects training samples of the radio wave strength and the person's position during no shielding. Our method estimates the person's position using a regression model with only the radio wave strength acquired from the wireless devices when shielding occurs. The experimental results show that the estimation error of the person's position was 15.9 ± 5.2 cm when one person existed at the same time in a poster panel area with temporary shielding and 18.7 ± 6.6 cm when two persons existed at the same time in that area.