Indoor Location-aware System Design And Implementation

With the development of computer and embedded technology, ubiquitous computing age is coming. In the ubiquitous age, people could get all kinds of services anywhere and at any time. It is necessary to know the users' location for achieving the goal of ubiquitous computing. The outdoor positioning has already been quite sophisticated, such as GPS, mobile telephone positioning, the satellite navigation system of "Galileo", and so on. They can provide good services for people in the outdoor environment. But the indoor environment is very complex, these outdoor positioning systems could be used hardly. With the development of information technology, now, people need urgently the indoor location.We design an indoor location system based on ultrasonic sensor and radio frequency technology. The ultrasonic positioning technology has many merits of high positioning accuracy, simple circuit structure and low cost. Therefore, it is applied widely for measuring distance and positioning area. The principle and the design of the system are detailedly described. The system consists of the single chip circuit, the circuit of ultrasonic, the circuit of radio frequency signal, communication interface circuit and so on. They are all detailedly described. It is programmed in C language. We use the TOA algorithm to calculate the coordinate of the users, and design the circuit board of the system and make the experiment.The goal of the indoor location aware system is to give people all kinds of services. In the end, we design several indoor location based service systems. The location which the location aware system provides is used to control the lights, look after the children and the old people and control the air conditioning, television and so on.