Self-Localization Method Using a Single Acoustic Ranging Sensor Based on Impulse Response and Doppler Effect

This study aims to realize self-position estimation for indoor robots using only a single acoustic channel. When a single omnidirectional transmitter/receiver is used as an object detection sensor, detected objects are identified on concentric circles with the transmitter/receiver as the center point. Self-position estimation method using this sensor cannot use the directional information of the detected object. This fact makes it impossible to specify the robot's turning angle using environmental information. In this article, we propose a self-position estimation method using a single omnidirectional transmitter/receiver that can consider the direction of the reflected object by estimating the direction of the reflected wave from the Doppler effect generated during the robot's movement. The self-position estimation was implemented by using echo images of the direction of arrival of sound waves estimated from the Doppler effect and the distance of arrival of sound waves estimated from the impulse response and matching them with a previously generated map image. The accuracy of the proposed method was evaluated by simulation and experiment. In the simulation, an average position estimation error of 0.042 m was achieved; in the experiment, it was 0.051 m. Furthermore, experimental and simulation results show that using the Doppler effect contributes to self-position estimation accuracy.