US Patent 9157749 Position calculation method and position calculation apparatus

A position calculation method includes: by using a current position of a mobile object, a link candidate point position, an error variance of positions of a plurality of links included in a region around the current position, and an error variance of azimuths of the plurality of links, calculating, an evaluation value that corresponds to a probability that the mobile object is traveling upon a road corresponding to each link candidate point, for each link including the each link candidate point; and calculating the current position based upon the evaluation value, by taking the mobile object as being positioned at a link candidate point, among a plurality of link candidate points, for which the probability is highest.