Position calculation method and position calculation apparatus

摘要

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.

主权项

1. A position calculation method, comprising:
providing a reception device that receives a position measurement signal emitted from a position measurement satellite, and a measurement device that measures sensor data including at least one of a speed, an angular velocity and an acceleration of a mobile object; calculating, by a processor, a current position, a shifting speed and an azimuth of movement of the mobile object; calculating, by the processor, an estimated error covariance of the current position and the azimuth of movement based upon the current position, the shifting speed and the azimuth of movement; calculating, by the processor, an evaluation value that corresponds to a probability that the mobile object is traveling upon a road corresponding to each link candidate point of a plurality of link candidate points included in a predetermined region that includes the current position, for each link including the each link candidate point, wherein the evaluation value is calculated using the current position, the azimuth of movement, the estimated error covariance, a link candidate point position of the each link candidate point, a link candidate point azimuth of the each link candidate point, a first error variance of positions of a plurality of links included in the region, and a second error variance of azimuths of the plurality of links, the evaluation value is calculated based upon a distance between the current position and the link candidate point position and based upon an azimuthal difference between the azimuth of movement and the link candidate point azimuth, and the evaluation value is calculated by adding together a plurality of data items including the distance and the azimuthal difference obtained at each of predetermined intervals up to the link candidate point position; calculating, by the processor, the current position based upon the evaluation value, by taking the mobile object as being positioned at a link candidate point, among the plurality of link candidate points, for which the probability is highest; and outputting guidance information to a display and audio device based on calculations performed by the processor; wherein: the processor calculates the current position the shifting speed and the azimuth of movement based upon the position measurement signal and the sensor data; and the processor calculates the estimated error covariance using the position measurement signal and the sensor data.