Autonomous movement device, autonomous movement method, and non-transitory recording medium

An autonomous movement method, comprising:

• controlling an autonomous movement based on information on a plurality of images picked up by a camera;
• obtaining a feature point in an image among the plurality of images picked up by the camera by analyzing the image;
• storing, in a map memory, a position of the obtained feature point;
• obtaining a corresponding feature point number that is a number of correspondences between a presently obtained feature point and a previously obtained feature point whose position is stored in the map memory;
• sequentially storing an image picked up by the camera in an image memory;
• estimating a local device position based on the position of the feature point stored in the map memory;
• determining whether an estimation status of the local device position is a tracking successful status or a tracking unsuccessful status based on the obtained corresponding feature point number;
• obtaining a corresponding feature point number by referring to a predetermined image among a plurality of images sequentially stored in the image memory when the estimation status of the local device position is determined to be in the tracking successful status, and obtaining a corresponding feature point number by referring to a previous image which is an image stored prior to the predetermined image among the plurality of images sequentially stored in the image memory when the estimation status of the local device position is determined to be in the tracking unsuccessful status;
• and
• controlling the autonomous movement in accordance with the obtained corresponding feature point number.

A nontransitory computer readable storage medium having stored thereon a program that, when executed, cause one or more processors to perform functions comprising:

• controlling an autonomous movement based on information on a plurality of images picked up by a camera;
• obtaining a feature point in an image among the plurality of images picked up by the camera by analyzing the image;
• storing, in a map memory, a position of the obtained feature point;
• obtaining a corresponding feature point number that is a number of correspondences between a presently obtained feature point and a previously obtained feature point whose position is stored in the map memory;
• sequentially storing an image picked up by the camera in an image memory;
• estimating a local device position based on the position of the feature point stored in the map memory;
• determining whether an estimation status of the local device position is a tracking successful status or a tracking unsuccessful status based on the obtained corresponding feature point number;
• obtaining a corresponding feature point number by referring to a predetermined image among a plurality of images sequentially stored in the image memory when the estimation status of the local device position is determined to be in the tracking successful status, and obtaining a corresponding feature point number by referring to a previous image which is an image stored prior to the predetermined image among the plurality of images sequentially stored in the image memory when the estimation status of the local device position is determined to be in the tracking unsuccessful status;
• and
• controlling the autonomous movement in accordance with the obtained corresponding feature point number.