| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a monitoring sensor which can detect an obstructing action by which a direction of the monitoring sensor is changed.SOLUTION: A monitoring sensor 2 comprises: a detection part 21 for creating distance measurement data which correlates multiple scanning directions over a whole monitoring area and distances to an object corresponding to the respective scanning directions; a storing part 23 for storing past distance measurement data as reference data; a direction variation detection part 243 which compares the present distance measurement data with the reference data while displacing them in an angle direction of the scanning direction and detects angle displacement amount with which the present distance measurement data and the reference data are coincided with each other the best as a displacement angle of the monitoring sensor 2; and a direction variation abnormality detection part 244 for detecting whether abnormality of direction variation with which at least one part of the monitoring area cannot be monitored is generated or not according to the displacement angle.</p> |
