The Preparation Of Flexible MEMS Wind Sensor And Its Application In Plant Protection UAVs

In terms of solving problems of pesticide drift and low spraying efficiency caused by environmental wind speed in the spraying operation of Plant protection Unmanned aerial vehicles（UAVs）,this thesis proposes a scheme based on the combination of micro-electromechanical system（MEMS）thermal wind speed sensors and UAVs,to optimize operations of UAVs and reduce pesticide drift.The main research contents of this thesis are as follows:（1）Taking the UAVs as the application scenario,design,preparation and thermistor calibration of the chip are completed based on the MEMS processing technology.Polyimide and platinum are selected as the sensor substrate and thermistor material respectively;the MEMS preparation process such as magnetron sputtering technology,electroplating and photolithography has been used to realize the preparation of a new flexible MEMS wind speed sensor with a cavity.The wind sensor has the advantages of small size,high sensitivity,and fit to curved surfaces.（2）Based on the principle of heat loss and thermal temperature difference,the design and optimization of the sensor test circuit are completed,and the zero drift problem caused by the temperature of the sensor is solved,the sensitivity and accuracy of the sensor are improved.The linear relationship between the output voltage of the sensor and the ambient wind speed is obtained through the test and the relationship is obtained through regression analysis.The measuring range of the sensor is 0-30m/s,the sensitivity can reach 12.59m V/ms^-1,and the environmental wind direction can be judged at the same time.（3）A UAVs targeted pesticide application system with a flexible MEMS wind speed sensor is proposed.The MEMS wind speed sensor is used to collect environmental wind information.Based on Keil5,a program for sensor signal acquisition and steering gear nozzle driving module is developed,and finally verified by actual experiments.The test results show that the plant protection drone targeted pesticide application system can improve the pesticide drift phenomenon caused by the environmental wind speed of UAVs to a certain extent.