Self-localization estimation device

A self-localization estimation device comprising:

• a map-information acquisition unit that acquires map information including lane information for specifying lanes in which vehicles are enabled to travel;
• an in-lane localization detection unit that detects in-lane localization information for specifying an in-lane position of an own vehicle, the in-lane position being a position of the own vehicle in a lane in which the own vehicle is travelling;
• an absolute localization estimation unit that estimates absolute-localization information for specifying an absolute position of the own vehicle and an error in the absolute localization;
• a self-localization estimation unit that:
• estimates, based on the map information, the in-lane localization information, and the absolute-localization information, a position of the own vehicle corresponding to lane information included in the map information;
• determines, based on mutual relationships between the in-lane position and the absolute position including the error, whether there is lane-relevant candidate information, the lane-relevant candidate information representing that one or more in-vehicle positions are each estimated to be in which of lanes identified by the lane information;
• and
• estimates, based on a result of the determination of whether there is lane-relevant candidate information, a localization of the own vehicle corresponding to the map information.