Study on ZigBee Indoor Position

• Main Authors: Chiu-Wen Chen, 陳秋汶
• Other Authors: Jong-Jiann Shieh
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/17774668463832543785

碩士 === 大同大學 === 資訊工程學系(所) === 100 === ZigBee is an important technology of wireless sensor network in the era of an aging population and the shortness of medical care workers. ZigBee’s application can reduce burden of medical workers, on measure blood pressure, temperature, and heartbeat. In hospital, patients usually wait workers for regular check, or medical staff not fined the patient lead to delay other patients’ times. In this paper we propose an indoor location system use ZigBee. That patient can get a certain degree of freedom. Let patients not only in the room to wait for checking, but also not worried about patient’s place for medical staff. In our measurements, RSSI values usually effect by environment, like the wall, floor, and human, called the multipath effect. Human body can strengthen RSSI values; this will reduce the accuracy of location. The received RSSI value need using RSSI propagation model convert to distance. But let RSSI values immediately convert to the distance is difficult, because our measurements show RSSI value affected by multipath effect, so we can’t get an accuracy distance. In order to improve the accuracy of using RSSI value, we take human body into consideration to find a set of weighted RSSI values and previous position to get the regulate location point. Our experiment in an indoor environment and set the reference nodes let mobile node usually only two reference nodes signal can receive. Experiment result show the average error is 1.88 meters.