Patent ID: 7777673

Claim:
A positioning method comprising: executing a first positioning mode or a second positioning mode, an LS positioning process that is performed using a least-square method based on a positioning signal and a KF positioning process that is performed using a Kalman filter based on the positioning signal utilizing a positioning result obtained by the LS positioning process as a base value being performed in the first positioning mode, and the KF positioning process being further performed in the second positioning mode utilizing a positioning result obtained by the KF positioning process as a base value; determining a located position calculated by a currently executed positioning mode to be a candidate position; determining accuracy of a positioning result obtained by the KF positioning process performed in the currently executed positioning mode; changing the positioning mode to be executed to the first positioning mode or the second positioning mode corresponding to the accuracy; calculating a dead-reckoning position by performing a dead-reckoning process using a velocity vector obtained by the currently executed positioning mode; and determining an output position by calculating a weighted average of the candidate position and the dead-reckoning position based on an estimated error of the KF positioning process performed in the currently executed positioning mode.