Localización y posicionamiento en interiores mediante el uso de sensores Cricket
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Date: July 2014
Author: Eleazar Caballero Sánchez
Tutor: Dr. Rafael Pérez Jiménez
Abstract
Tracking and location systems have become common in our lives. However, many of these services are strong dependent to the coverage of the used device, which means that indoor locations or even remote outdoor locations do not have access to such services. Some indoor location systems have been developed to solve this issue. For example, Radio frequency tags or trilateration systems supported on Bluetooth, WiFi or ZigBee technology are used for indoors location.
In June 2005, the Massachusetts Institute of Technology published the PhD thesis called "The Cricket Indoor Location System", which describes the mathematical formulation and methodology for carrying out the implementation of a new indoor location method, the Cricket sensors. This new location technology uses a combination of radio frequency and ultrasonic signals to provide the location of the sender device leveraging that radio signals propagation speed is faster than the ultrasonic signal. First, a radio beacon alerts the receiver devices which run up a timer until receiving the ultrasound signal. By knowing the delivery time and the signals propagation speed, the receiver can run up an algorithm to provide the best possible correlation of the position of the sender device.
Based on this, the objective of this master's work is the implementation of a Cricket based system by programming a PIC microcontroller and its verification through appropriate laboratory tests.