Self-position estimation method

A self-position estimation method of estimating, from detection information of a plurality of sensors, a self-position of a mobile object by using each of a plurality of algorithms each using detection information of one or more of the plurality of sensors, and specifying the self-position of the mobile object based on an estimated value of the self-position obtained by each of the plurality of algorithms,

• the plurality of algorithms including an A-th algorithm which is a Monte Carlo Localization (MCL) algorithm and a B-th algorithm different from the MCL algorithm, the self-position estimation method comprising:
• a reliability determination step of determining a level of reliability of an A-th self-position estimated value which is an estimated value of the self-position obtained by using the A-th algorithm;
• and
• a correction step of performing, in a case where it is determined that the reliability of the A-th self-position estimated value is low, processing for correcting the A-th self-position estimated value by using any one of a self-position specified value which is the specified self-position, a B-th self-position estimated value which is an estimated value of the self-position obtained by using the B-th algorithm, and an estimated value of the self-position obtained by estimation using the MCL algorithm under an estimation processing condition different from an estimation processing condition of the A-th algorithm.