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Terminal Selection Using Acoustic Triangulation Technique

IP.com Disclosure Number: IPCOM000060906D
Original Publication Date: 1986-May-01
Included in the Prior Art Database: 2005-Mar-09
Document File: 2 page(s) / 67K

Publishing Venue

IBM

Related People

Broockman, EC: AUTHOR [+2]

Abstract

This article describes an acoustic triangulation technique for selecting one of several terminals located in acommon area. Piezoelectric transducers deployed in the common area can produce bursts of ultrasonic energy at different frequencies. By controlling the relative delays of bursts from different transducers, the bursts can be made to overlap in time at a given physical location within the common area. A terminal which hears overlapping bursts assumes it has been selected for communication with a master terminal. Wireless communication technology is used to allow a selected terminal to communicate with the master terminal. Fig.

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Terminal Selection Using Acoustic Triangulation Technique

This article describes an acoustic triangulation technique for selecting one of several terminals located in acommon area. Piezoelectric transducers deployed in the common area can produce bursts of ultrasonic energy at different frequencies. By controlling the relative delays of bursts from different transducers, the bursts can be made to overlap in time at a given physical location within the common area. A terminal which hears overlapping bursts assumes it has been selected for communication with a master terminal. Wireless communication technology is used to allow a selected terminal to communicate with the master terminal. Fig. 1 shows several hyperbolic curves on which which bursts of ultrasonic energy from spaced transducers A and B will be detected simultaneously for given relative time delays between the energy bursts. As one example, if there is no delay between the two bursts, the bursts overlap in time along a straight line 10 equidistant between the transducers. If one burst is delayed slightly relative to the other, the bursts will overlap along either of curves 12 and 14, depending on which burst occurs first. If one burst is delayed considerably relative to the other, the bursts can overlap along either of curves 16 and 18. Fig. 2 is a plan view of a common area, such as a classroom, in which terminals 20A, 20B, 20C, etc., are arranged at intervals. Piezoelectric transducers A, B, C and Dare arranged on one wall of the common area. Each of the transducers is capable of generating a burst of ultrasonic energy at a unique frequency. The transducers are connected to and are controlled by a master terminal 22. An antenna 24 connected to master terminal 22 may be located on the same wall. By controlling the relative time delays between the burs...