| 摘要 |
<p>A system for tracking the position of each of a plurality of labelled objects in a specified environment by determining the transit time of ultrasound signals transmitted from a transmitter on each labelled object, to a plurality of ultrasound receivers positioned at fixed points in or around the specified environment, and computing therefrom the distance of the transmitter from the receivers. The ultrasound transmissions are initiated by radio signals from a master transmitter and each of the objects includes a radio receiver adapted to respond to the radio transmissions to initiate a burst of ultrasound. In order to allow the system to adapt to different numbers of transponder-transmitters and differing demands for service (e.g. frequency of position determination per transponder-transmitter), a coordinating control system is provided for determining the order in which the object mounted transponder-transmitters are to be triggered by the radio transmissions, in response to updatable information relating to the objects and related service demands.</p> |
