Indoor Environment Intelligent Monitoring And Comfort Degree Valuating System Based On NI Wireless Sensor Wetworks

With the development of social productivity and the improvement of life quality, the quality of people’s life demand is higher and higher. And we pay more attention to the indoor environment which is closely to our life and work. The development of wireless sensor networks is changing the interactive way of humans and nature. And the capacities of human’s information acquisition, transmission and processing are promoted. Its technology is becoming more and more mature. In the side of the wireless sensor network technology and products, the National Instruments (NI) company does very well. The products of the company have many advantages. The sensor nodes are simple and easy to use. And they are reliable, cost-effective and low power consumption. The application prospect is broad. Applying the NI wireless sensor network to the indoor environment monitoring system is more advantageous to our collect, transfer and deal with the environmental parameters.By the effective monitoring of the indoor environment, it provides the basis for regulating and controlling the indoor environment.We propose to build an indoor environment intelligent monitoring and comfort degree valuating system which is based on NI wireless sensor network. The system can monitor the indoor environment parameters of fire signal, smoke fog, temperature and harmful gas, dispose if there is fire danger and judge whether harmful gas exceed the standard. By monitoring the indoor environment parameters of temperature, relative humidity, noise and illumination, we use the theory of fuzzy comprehensive to evaluate the comfort levels of the indoor environment.The main work of this thesis is carried out as follows:Firstly, we design the overall scheme of the indoor environment monitoring system. And then we construct the hardware platform which is based on the NI wireless sensor network. Select the appropriate sensors and the corresponding auxiliary circuit to collect the environmental parameter information. Complete building three subsystems which are the fire monitoring subsystem, harmful gas monitoring subsystem and environmental comfort level monitoring subsystem.Secondly, Design visual interface design programming using Lab VIEW software, realize transferring the collected data and the remote monitoring based on the NI wireless sensor network. Disposing and controlling the data are divided into three modules:the fire monitoring unit determines if there is a danger of fire in the door, raising the alarm or sending the messages to the user, when the fire will broke out; the harmful gas monitoring unit monitors the harmful gases, sending out the voice remind when one of the harmful gases is beyond the standard; the environmental comfort unit judge the comfort level of the indoor environment and light the results in the form of marking.Then, build the model of indoor environmental comfort evaluation system based on Fuzzy Theory. Determine the membership function of temperature and humidity by combining the datum and experimental data. Build the model of indoor thermal environment comfort degree based on the proportion of temperature and humidity effecting on human thermal comfort. Selection the Sigmoid membership function and the Gauss membership function based on the datum and experimental data, build the evaluation model of sound and luminous environmental comfort degree. Select the measured value of the temperature sensor, humidity sensor, noise sensor, illumination sensor in this system to constitute the factor set of the comprehensive evaluation system. Divide the evaluation set of indoor environmental comfort degree into more comfortable, comfortable and uncomfortable. Establish the evaluation function from factor set to evaluation set. Combining the analytic hierarchy process and 1-9 rating scale method, solve the weight vector of different factors influence on the final evaluation results. Thus build the comprehensive evaluation model of indoor environmental comfort degree.Finally, we debug the whole indoor environment monitoring system which is based on NI wireless sensor network, test the accuracy of the models, which are the evaluation models of the indoor thermal, sound, luminous and comprehensive environmental comfort degree.