Comfort Measurement And Control System For Smart Home Based On Wireless Sensor Networks

With the development of the living standard, the demand on living environment quality is higher and higher. A living environment with satisfying comfort can not only improve people’s life quality and work efficiency but also contribute to good health. Human comfort consists of visual comfort, thermal comfort and air quality which involve luminance, temperature, humidity, air flow and harmful gas density.Most measurement and control systems for smart home either focus on the communication between home and devices instead of the comfort control decision, or make control decisions for the environment parameters uniformly which reduce the system efficiency.With the fact that related technology is maturing, the application of wireless sensor networks in smart home becomes more extensive. Compared with cable networks, wireless sensor network need no specified communication lines which minimize the installation and wiring costs. With a better openness, networks could extend easily as the scope of user activities expands.In this paper, a comfort measurement and control system for smart home based on wireless sensor networks is proposed. The system is divided organically according to the correlation among environment parameters to improve the system efficiency. Meanwhile, the on-line learning function is introduced into the system to improve the intelligent degree of the system.Firstly, research background and research status at home and abroad has been introduced and the main contents have been expatiated. The architecture of the comfort measurement and control system has been described. The control strategy for visual comfort, thermal comfort and air quality has been presented. In view of indoor thermal comfort measurement and control, a wireless sensor network has been designed to accomplish the acquisition and control of the parameters that influence the human comfort such as temperature, humidity, air flow, luminance and air quality. First of all, the system structure of the wireless sensor network has been designed. Then the design of the node hardware and software has been detailed including the selection of microcontrollers and RF chips, the design of extension modules and the coding of the node programs. At last, the organization of the wireless sensor network has been implemented and the operation process of the wireless sensor network has been described.A host computer program for embedded system based on the ARM9platform has been designed. Firstly the transplantation of SQLite has been accomplished. A GUI has been designed based on Qt for users to inquire or control the environment parameters.After the implementation of the comfort measurement and control system, experiments have been carried out to measure the PMV index and to test the control of the dynamic comfort and the comprehensive properties of the comfort measurement and control system.