Indoor personnel tracking using infrared beam scanning

This paper describes an infrared-based system for tracking personnel in an indoor environment. The system uses three corner mounted infrared transmitter units, each consisting of eight infrared diodes, and a receiver unit worn by a user to determine the position of the user. Every diode of each transmitter unit scans the area sending its own unique code sequentially which can be decoded to identify both the transmitter and its beam angle when picked up by the receiver unit. The received codes are then sent to a personal computer (PC) to determine the position of the user by the method of triangulation. The prototype system built has a position update rate of once every 250ms with an accuracy of 0.57 metres. The system, whose accuracy could be improved with the use of better focusing elements for the infrared beams, should rind applications in the areas of military training, where the position of soldiers can be monitored throughout training sessions in buildings with multiple rooms, and any other applications that require the tracking of moving objects.