초음파 기반의 트램 승객 승하차 판단 시스템 개발 및 검증

초록

In this paper, a system that can determine whether a passenger is on the tram by using only the ultrasonic generator inside the tram vehicle and the built-in microphone of the smartphone was proposed. Due to the probabilistic uncertainty of radio waves, determining whether a passenger is on the tram by using existing local wireless communication methods (e.g., WI-FI and BLE) is difficult when a passenger is near the boundary between the interior and exterior of the vehicle. To overcome this problem, in this study, ultrasonic signal, which has excellent shielding property between obstacles or barriers, was used to determine the interior or exterior of the vehicle. The door of the vehicle is closed, and the indoor ultrasonic generator emits ultrasonic waves of a specific frequency only under certain driving conditions. We developed a smartphone app based on the discrete Fourier transform algorithm to determine whether a passenger is on the tram. We installed the system on a tram of the Osong Tram Test Line and evaluated its effectiveness.

키워드