Abstract: The present invention provides a device and a method which allow a travel direction of a moving body to be estimated more efficiently. The present invention provides a travel direction estimating device for estimating a traveling direction in which a moving body travels, including: an accelerometer for detecting an acceleration by which the moving body travels; an angular velocity sensor for detecting an angular velocity by which the moving body travels; and a travel direction vector determining section for determining the traveling direction of the moving body by calculating, based on the acceleration detected by the accelerometer and on the angular velocity detected by the angular velocity sensor.

Abstract: The present invention reduces an arithmetic operation amount for updating a state vector. The attitude estimating device includes (i) a gravitational direction estimating section for updating, by using an acceleration vector as an observation, a gravitational direction vector predicted from an angular velocity vector, (ii) a horizontal direction estimating section for updating, by using a magnetic vector as an observation, a horizontal direction vector predicted from the angular velocity vector, and an attitude estimating section for generating attitude information with use of the gravitational direction vector and the horizontal direction vector.