Design And Implementation Of A System To Locate Elderly Living Alone And To Monitor Indoor Environment

The number of elderly people is increasing rapidly around the world, and the trend is not going to ease in the foreseeable future. A big problem of an aging population is the guardianship of elderly people living alone. When the cost of elderly caring becomes bigger and bigger, there is an urgent need for an intelligent monitoring system to reduce the manpower and material resources and financial cost for the elderly caring.At the same time, due to the rapid development of sensor technology and digital IC technology, wireless sensor network technology has got a blowout develop in the last decade. Wireless sensor network technology has been widely applied to the smart home, smart agriculture, intelligent medical, intelligent transportation, building automation, retail services and telecommunication business and other fields. The combination of wireless sensor network technology and elderly caring has almost become a necessity.In this paper, I analyzed the existing elderly monitoring system and proposed a new system based on ZigBee technology and sensor technology. The main contents of this paper are as follows:(1) Designed and implemented a watch-cellphone.The watch-cellphone has GPS and Assisted GPS and one-touch dialing functions. It can also answer a phone call and send or receive SMS and display. It has ZigBee functions and can be a node of a ZigBee network;(2) Created a ZigBee network indoor.Added an environment perception node to the network to monitor the indoor environment parameters, such as the concentration of carbon dioxide, temperature, relative humidity and light intensity. Designed a flow sensor node and a current sensor node to measure water flow and electric current;(3) Added indoor positioning nodes to the ZigBee network. The indoor positioning nodes were implemented by beam infrared sensor. There are three kinds of indoor positioning nodes in the network, they are bed sensor node, door sensor node and urinal sensor node. The data collected by these nodes could tell where the elderly is and whether he or she is in bed or on the toilet when he or she is indoor;(4) Tested the system, including hardware testing, the ZigBee network testing and system function testing.