Design And Experimental Study On Measurement And Control Circuit Of Bionic Hair Sensor

In recent years,the development of bionic technology has brought more and more inspiration to sensor design,and the development of bionic sensor has also made a breakthrough.The biomimetic hair sensor studied in this paper is designed for the measurement of flow using animal hair structure as reference.Flow measurement is of great significance in meteorological testing,environmental protection,industrial and agricultural production.The purpose of research on bionic hair sensor is to improve the accuracy of flow measurement.The structure of hair sensor determines the upper limit of measurement precision,and the measurement and control circuit is the key to realize the measurement function.Therefore,this paper mainly studies the measurement and control circuit of hair sensor,the main research contents are as follows:(1)Study on flow sensitivity mechanism of hair SensorAccording to the mechanical structure of the hair sensor,the dynamic model of the resonator and the force model of the cylindrical hair under the flow are introduced,and the relationship between the frequency change of the resonator and the size of the flow is obtained.Secondly,the principle of electrostatic drive and capacitance detection of hair sensor is analyzed,which provides a theoretical basis for circuit design.(2)Design and analysis of driving circuit for hair SensorThe driving circuit based on PLL is designed,including frequency control loop and amplitude control circuit.The phase detector,loop filter,voltage controlled oscillator in frequency control circuit and rectifier circuit,low pass filter in amplitude control circuit are analyzed.Finally,the MATLAB simulation of the driving circuit based on PLL is carried out,and the correctness of the analysis is verified.(3)Design of flow generation circuit and microphone calibration circuitFirstly,the mechanism of producing air flow by loudspeaker is introduced,and the measurement and control scheme of flow generation circuit is designed,and analyze the audio amplifier circuit.Then,the principle of microflow measurement by microphone is introduced,and the measuring and controlling circuit is designed.(4)Realization of control algorithm for measurement and control circuit on FPGAFirstly,the peripheral hardware circuit based on FPGA controller is designed.Secondly,Basis on the previous theoretical analysis,the Verilog codes of digital phase-locked loop,filter,data analysis module and PI controller are compiled,and modelsim simulation is carried out to verify the correctness of the functions of these code modules.(5)Flow measurement experiment of hair sensorAfter the actual circuit is made and debugged,the flow measurement experiment of hair sensor is carried out,including: phase locked loop performance test,scale factor test,directivity test and so on.The experimental results verify the feasibility of the sensor measurement and control circuit designed in this paper,and indicate that the hair sensor can be very sensitive to the flow and has good directivity.