Patent ID: 8868372

Claim:
A position detecting system comprising: a detected object including a magnetic-field generating unit that generates a magnetic field; at least one magnetic sensor configured to detect the magnetic field generated by the magnetic-field generating unit; a position detecting unit configured to calculate, based on a detection value of the at least one magnetic sensor, at least one of a position and a direction of the detected object; a memory unit configured to store a calculation result of the position detecting unit; a predicting unit configured to calculate, based on the calculation results at a plurality of times different from one another stored in the memory unit, a moving amount by which the detected object is predicted to move between a first time when the position detecting unit calculates the at least one of the position and the direction of the detected object and a second time after a predetermined time from the first time, and to predict, based on a calculation result of the position detecting unit at the first time stored in the memory unit and the moving-amount calculation result, at least one of a position and a direction of the detected object at the second time; and a control unit configured to control the position detecting unit based on the at least one of the position and the direction of the detected object at the second time predicted by the predicting unit, wherein: the position detecting unit is configured to change, when a detection value of the at least one magnetic sensor is set as a true value and a predicted value of the magnetic sensor predicted under an assumption that the detected object is present in an estimation position is set as an estimation value, the estimation position such that a difference between the true value and the estimation value is equal to or smaller than a predetermined value, and the control unit is configured to change an initial value of the estimation position.