POSITION SENSOR

摘要

When the error value of optimization convergent calculation of position information and direction information on an object to be sensed has diverged, the convergent state of the error value can be reset in a short time. A position sensor (10) comprises a magnetic field sensing unit (11) for sensing the magnetic field produced by a magnetic field producing section (2b) in a capsule endoscope (2), a position calculating unit (13) for calculating position direction information on the capsule endoscope (2) by conducting optimization convergent calculation using an evaluation function expressing the error between the measured and theoretical values of the sensed magnetic field information, a storage unit (15) for storing therein convergence result information (15a) including the final convergence result of the optimization convergent calculation, and control unit (16) for controlling them. The control unit (16) judges whether or not the result of the optimization convergent calculation has converged, stops the position calculating unit (13) if the result is judged not to have converged, and allows the position calculating unit (13) to start the optimization convergent calculation using the final convergence result after a predetermined time has elapsed.