LAUSR

Abstract A flow line measurement method that utilizes radio waves and ultrasonic sensors is proposed. A smart watch and several smartphones are used in the measurement system. The smart watch, attached to the object of interest, transmits information such as acceleration via Bluetooth Low Energy. When the smartphones receive a signal, the general position of the object is estimated based on the signal strength. Then, ultrasonic sensors near the general position are used to estimate the position with higher accuracy. The proposed system was tested in a measurement area of 14 m × 14 m under conditions that make it difficult to measure the flow line using traditional methods. The results show that the flow line can be measured using the proposed method in an environment with many obstacles.