| 摘要 |
Room occupancy is sensed by delivering a series of light pulses (22, fig. 1) via a plurality of waveguides (e.g. optical fibres) to one or more output nodes 60 located in each of a plurality of rooms 10. The scene in each room 10 reflects the light pulses (22), and the reflected light pulses (24) are detected. A difference between the detected waveform of a first light pulse reflected from the pulse emitted from an output node 60 and the detected waveform of a second reflected light pulse from the same output node is monitored. This monitoring step is performed for each of the output nodes 60. Movement is detected in a room 10 by detecting such a difference between detected waveforms, and the particular room in which movement has occurred is ascertained. There may be single or multiple light sources and the light pulses may be produced by a laser. A signal processor may be used to monitor the difference between the detected waveforms. The sensing apparatus may comprise one or more transducers for converting light signals into electric signals. |
