| 摘要 |
A monitoring device 10 monitors a container for transporting cargo and comprises a transmitter to transmit data provided by sensors 20, 60, that sense container variables and an electrical storage device 40 to provide electrical power to the sensors and data transmitter. The monitoring device selects from plural sensors an available sensor having an accuracy greater than a threshold. An energy transducer 50 may provide power to the sensors, data transmitters and electrical storage devices that is converted from thermal, kinetic or solar energy and can provide power to the sensors and the transmitter in preference to the storage device. Thermal energy can be converted from inside or outside the container using a heat engine having a fluid in a thermodynamic cycle, a thermoelectric generator or a Peltier device. Kinetic energy can be converted using a movable mass or a piezoelectric accelerometer and exploit movement of the container in a range of directions. Monitoring devices can sense door position, mounting, tampering, light levels, temperature, pressure, altitude, acceleration, battery level, humidity and position using a GPS, GSM WPS or RF location device. Data transmitters can communicate with a server using GSM, GPRS, SMS, Wi-Fi, or a satellite transmitter and receive data to configure the monitoring device. |
