POSITION DETECTION DEVICE, POSITION DETECTION METHOD, MOBILE OBJECT, AND RECEIVER

摘要

In a case where multiple mobile objects are used simultaneously, the position of each of the multiple mobile objects is accurately detected without being influenced by ultrasonic waves from any other mobile objects. A mobile object is provided with a means for transmitting a trigger signal requesting permission to transmit ultrasonic waves, this trigger signal being capable of enabling the aforementioned mobile object to be identified; a means for receiving from a receiver a trigger signal giving permission to transmit ultrasonic waves; and a means for transmitting ultrasonic waves as soon as the aforementioned trigger signal giving permission to transmit ultrasonic waves is received. The aforementioned receiver is provided with a means for receiving from the aforementioned moving object the aforementioned trigger signal requesting permission to transmit ultrasonic waves; a means for transmitting the aforementioned trigger signal giving permission to transmit ultrasonic waves, this trigger signal being capable of being identified by the aforementioned mobile object; a control means for controlling the transmission timing for the aforementioned trigger signal giving permission to transmit ultrasonic waves; at least two(2) ultrasonic wave receiving means which are set at a specified interval; a means for calculating the time for ultrasonic wave propagation from the aforementioned mobile object on the basis of the time when the aforementioned trigger signal giving permission to transmit ultrasonic waves is transmitted and the time when ultrasonic waves arrive; and a position calculating means for calculating the position of the aforementioned mobile object on the basis of the ultrasonic wave propagation time calculated.