| 摘要 |
<p>An embodiment of vehicle security system 10 described herein comprises a plurality of PIR sensors 12 mounted to the roof section of or detachable trailer of a HGV (40 Figure 2 ). The PIR sensors look down on the cargo area (45) and detect movement at the cargo area. They sensors are wireless and each have their own battery power supply, thus require little time to fit. An alarm unit 14 detects signals from the sensors and can trigger an alarm, either on the trailer, or remotely via a GSM type wireless communication device 16. The system 10 includes a GPS signal receiver built into the GSM communication device 16 to provide the geographical location of trailer. The alarm unit and GSM device may each be powered by a rechargeable battery, which may be topped up by a photovoltaic panel mounted 13 externally on the roof of the trailer.</p> |
