Design And Implementation Of Low Power MEMS Wireles Wind Sensor Node Measurement And Control System

Meteorological elements play an important role in many fields such as industry,agriculture,meteorological monitoring and environmental protection.In recent years,with the rapid development of MEMS technology and wireless sensor networks,MEMS thermal wind speed sensors applied to wireless sensor networks have been widely used in the meteorological field due to the advantages of miniaturization and convenience.Based on the chip structure of the latest thermal wind speed sensor designed in the laboratory,the following three aspects are designed: one is to design the hardware control circuit of the PID(proportion integral differential)control algorithm;the other is to design a series of software systems including PID control algorithm,wind speed and direction measurement and control algorithm;the third is to design software and hardware aspects of system power consumption.In the specific design,firstly,in order to match the software to implement the PID control algorithm,an independent temperature measuring circuit based on the temperature measuring diode is designed to avoid the mutual influence of the temperature signals on the hardware circuit;Secondly,in the implementation of the specific PID algorithm,the incremental control algorithm is used to stably control the temperature difference signal within the allowable range.For the temperature compensation problem,the linear interpolation algorithm is used to simplify the wind speed and wind direction calculation,which is beneficial to realize the sensor products;Finally,in reducing the power consumption of the system,this thesis starts from the MCU working mode and the power control module.It has both hardware design and software design to better reduce system power consumption.The actual test results show that the wind speed measurement range of the MEMS wireless wind sensor system is 0.5m/s~30.0m/s,the working range is 0°C~40°C,and wind speed and wind direction can reach(0.5m/s ± 5%v)and ±5°accuracy at different temperatures,and the average power consumption of the system is below 300 mW.In general,the indicators of the sensor system meet the established requirements.Two shortcomings of MEMS thermal wind speed sensors limit their use in wireless sensor networks.On the one hand,the hardware circuit is more complicated,the debugging is difficult,and the calibration workload is large;on the other hand,the system has high power consumption and cannot be used for long-term battery life in the wireless sensor network.This thesis makesgreat improvement in these two aspects,so that the sensor system will be more widely used in the future wireless sensor network.