| As a high and new technology with the most development prospect and influence in the 20th century,sensor technology is constantly applied in various industries and is attracting great attention at home and abroad.Therefore,it is of great significance to study the measurement accuracy and stability of the sensor.Since the differential solenoid displacement sensor has high sensitivity,high reliability and long service life,it is widely used in harsh environment of oil pollution and high temperature etc.,but the sensor has the problems of zero residual voltage,nonlinearity and is easy to be affected by temperature.Therefore,this paper deeply studies three key problems of zero residual voltage,nonlinear characteristics and temperature drift characteristics of the sensor,and puts forward methods to solve these three key problems.The main research contents are as follows:?1?In order to solve the problem of zero residual voltage of differential solenoid displacement sensor,a hardware compensation circuit is designed to reduce the zero residual voltage.The compensation circuit consists of two adjustable potentiometers and a capacitor,in which the capacitor can eliminate the high-order harmonic components in the zero residual voltage,and adjusting the potentiometer can reduce the zero residual voltage.By comparing the zero voltage output waveform before and after compensation,it is found that only the external electromagnetic wave with small amplitude is left in the compensated output voltage waveform,and the zero residual voltage is greatly weakened.?2?Linearity is one of the important indicators of sensor accuracy.In order to solve the nonlinear problem of the sensor,the curve fitting method is used to correct the input and output characteristic curve,and the nonlinearity is improved from 1.62%to 0.87%.?3?In order to weaken the influence of temperature on the sensor,a temperature compensation model based on genetic optimization wavelet neural network?GA-WNN?is proposed in this paper.The zero temperature coefficient of the sensor is increased from6.82×10-3/?to 3.56×10-5/?,which is increased by two orders of magnitude.The sensitivity temperature coefficient increases from 8.21×10-3/?to 4.00×10-4/?,which is increased by an order of magnitude.The model effectively suppresses the effect of temperature on the sensor.?4?In this paper,a displacement measurement system is made by using STM32 single-chip microcomputer and differential solenoid displacement sensor.The hardware part mainly includes signal acquisition module,signal conditioning module,nRF24L01 wireless transmission module,display module,alarm module,button module and RS232 serial communication module.And the software part includes algorithms and subroutines of each module.Finally,after debugging,the system can run normally. |
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