| 摘要 |
The invention relates to a two-mode intrusion detection system comprising: (A) a plurality of spaced-apart magnetic sensing units, connected in chain-like manner, each sensing unit comprising: (a) a magnetic sensor s for sensing a 3-D magnetic field vector of the Earth; (b) an accelerometer for sensing a 3-D acceleration vector evolving from the acceleration g of the Earth; and (c) first communication means for conveying said sensed 3-D magnetic field vector and said sensed 3-D acceleration vector to a proximate processing unit; (B) one or more processing units, each processing unit comprising: (a) second communication means for communicating with one or more of said magnetic sensing units; and (b) a processor. In calibration mode, the sensed vectors are used to relate the physical components to a predefined coordinate system. In intrusion detection mode, sensed magnetic field measurements are used to determine the occurrence and location of an intrusion. |
