| 摘要 |
<p>A small-sized inexpensive state grasping device with high accuracy and an open/closure controller having such a state grasping device are provided. The state grasping device is provided to an electromagnetic operation device composed of a fixed iron core, a movable iron core, an electromagnetic coil, and a permanent magnet so as to grasp the state of the electromagnetic operation device. The state grasping device comprises current measuring means for measuring the current flowing through the electromagnetic coil, magnetic flux measuring means for measuring the magnetic flux in the fixed iron core, computing means for performing computation of the current variation waveform representing the temporal variation of the output signal from the current measuring means and the magnetic flux variation waveform representing the temporal variation of the output signal from the magnetic flux measuring means and generating a computed waveform, and state judging means for determining a feature point of the computed waveform and judging the state of the electromagnetic operation device on the basis of the information on this feature point.</p> |
