Foreign substance detection device, moving body control system including foreign substance detection device, and moving body including moving body control system

A foreign substance detection system (300), a moving body controller (102, 103, 106, 108, 109), and a moving body (100) each of which includes an optical device (220) having an input surface (223) through which a part of light emitted from a light source enters the optical device (220) and a transparent face, provided in close contact with an inner surface of a glass (105), to transmit a light reflected from an area where a substance is not present on an outer surface of the glass (105) toward a first light-receiving member (206); a light-guiding member (226) to guide another part of the light that does not pass through the input surface, the guided light being to be reflected from an area where a substance is present on the inner surface of the glass (105) toward a second light-receiving member (206); and a foreign substance detection processor (102) to detect an outer substance based on the first light-receiving member (206) and detect the inner substance based on the second light-receiving member (206).