Abstract:
Due to the development of industry and economy, the stock rooms for companies are getting bigger and bigger. The bigger it gets the harder it is to manage a stock room. There are all kinds of problems such as temperature monitoring to prevent fire, sensors for lost presentation, scanners and RFID tags for easy input, computers for remote control etc. Yet another very important thing is positioning algorithm. In order to solve a problem you have to know where the problem is. A good positioning method can be used in many applications like military, sports, medical applications and not just stock control. That is why so many researchers are working on indoor positioning methods. Indoor environment is different from outdoor; there are many reflection surfaces and obstacles to affect the movement of the signal. So indoor positioning is difficult especially for high accuracy positioning. This project is therefore proposed with two aims: to develop a proof of concept design for a system that can monitor the stock room environment; and the most important part, to research, study and improve existing positioning methods for indoor environment. This thesis focuses on the theory of indoor positioning, the obtaining of local power, positioning algorithm development and the measurement of received signal strength. Measurements were carried out to give us a better understanding of indoor signal propagation and to improve the existing positioning methods. The theoretical research about the local average power, the two-ray reflection model and log-normal model has been done as well. Three-ray reflection model is proposed and derived from the two-ray model. This method is also tested and compared with log-normal model in this thesis. Other than that researches on what kind of wireless technology for stock control system has been done together with the hardware design using TI’s CC2430 develop devices. Overall, the goal of this study is to achieve an accurate, robust and effective method for indoor positioning.