Study On The Wide Temperature Range Compensation Method Of Pressure Sensor

Silicon piezoresistive pressure sensor has been widely used owing to its characteristics of high precision,sensitivity,stability and small size.They are also easy to be integrated.However,its output signal changes non-linearly with the change of temperature when put into use,because silicon piezoresistive has the characteristic of temperature drift,which also makes the performance index of the sensor cannot meet the requirements of industrial applications.In order to solve this problem,researchers at home and abroad started early to study methods of temperature compensation,many of which have been proposed since then.At first,only compensation for hardware was simply realized while accuracy was still not greatly improved.Then the compensation for software appeared and it not only improved the compensation accuracy but also reduced the hardware resources.Moreover,it also promoted the development of silicon piezoresistive pressure sensor.At present,many scholars have proposed a variety of methods to compensate the temperature and each of them has its own advantages.After comparing several methods which are commonly used,a combined method of cubic curve which is based on least squares and Newton interpolation is chosen to compensate the temperature in this paper.And the final compensation results achieved the desired ones.In this paper,silicon piezoresistive pressure sensor is studied from the following aspects:1.Structural Analysis.The structure of the sensor bridge and the temperature drift are analyzed theoretically,and solutions of hardware are provided.2.Hardware System Design.Chips,like AD588,AD620,ADS1256,IAP15F2K61S2 and so on,are used to design the system modules and functions of acquisition,amplification,conversion,and display of sensor signals are realized.3.Calibration Experiments.Calibration experiments of sensor output data are conducted by using the designed hardware system and selecting 375 calibration points in the pressure range and temperature range of the sensor.4.Temperature Compensation.An overview of least square method,Newtoninterpolation method,which are commonly used,are provided.Cubic curve,based on least square method,and Newton interpolation is chosen to fit the calibration data points.Finally,the temperature compensation was realized in between-5 and 65 ?and compensated precision achieved 0.054%FS.5.Error Analysis.According to the precision of compensation,compensation error is analyzed theoretically from the aspects of experimental instruments,experimental procedures and data analysis.