Objective sensor, objective sensor dirt determination method, and object detection device

Abstract

An objective sensor, a dirt determination method thereof, and an object detection device according to the present invention, individually transmit transmission waves in a plurality of mutually different directions and receive the respective reflected wave thereof, through a protective member, so as to measure, with the plurality of directions as a plurality of measurement points, a transmission and reception time and the intensity of the reflected wave for each of the plurality of measurement points. Then, the objective sensor, the dirt determination method thereof, and the object detection device extract, as dirt candidate points, the measurement points each having the transmission and reception time shorter than a first threshold time and the intensity equivalent to or more than threshold intensity, regard the dirt candidate points that have been extracted, as the dirt points in a case where the dirt candidate points continue for a second threshold time or more, and acquire the dirt point distributions on the basis of the dirt points. Then, the presence or absence of dirt on the protective member is determined, on the basis of the dirt point distributions that have been acquired.