Temperature Compensation Of Piezoresistive Pressure Sensor Based On The Interpolation Of Third Order Splines

In the non-electricity detection, pressure was measured at most, so thepressure sensor is the most widely used, and the technical updating is also the fastest.Particularly, the silicon bridge piezoresistive pressure sensor with its goodlinearity,high sensitivity, small size, easy integration and many other advantages, hasbecame the most widely used pressure sensor at present. Because of the temperatureproperties of the semiconductor material, the signals of the silicon bridgepiezoresistive pressure sensor’s output would be affected with the change oftemperature, and due to temperature drift. The phenomenon of temperature drift haverestricted the development of silicon piezoresistive pressure sensor.With the development of national economy, many areas require sensors undervarious extreme conditions can still to maintain a high level of accuracy and stability.In order to enlarge the application scope of the sensors and the measuring accuracy, agroup of international and domestic concentrate on research, various methods oftemperature compensation have been proposed. Aimed at the current relativelypopular methods of temperature compensation doing the analysis and comparison inthis paper, Temperature compensation method based on the interpolation of thirdorder splines do the validation and improvement combined with the data acquisitioncircuit, proposed a new compensation method based on cubic spline interpolation, andthe experimental results was well.Take the silicon bridge piezoresistive pressure sensor as the research object,based on the analysis of the piezoresistive pressure sensor on the basis of the theoryand principle, the theoretical calculations of key parameters of the sensor andexploratory research. The concrete content includes the design of the deviceconfiguration, data acquisition circuit design, microcontroller compensation systemsoftware design and the temperature drift compensation experiment, make up aintegration design research of pressure sensor. The main research work in this paper isas follows: (1)The working principle of silicon piezoresistive pressure sensor was introduced,and the causes of temperature drift was discussed.(2)Made a stress simulation for elastic film of sensor with finiteelement emulation software named ANSYS, The film size and varistors were made atheoretical analysis, a scheme to optimize the design of the sensor’s sensingdiaphragm was proposed.(3)According to the overall design requirements, a data collector system ofhigh-precision was developed, the spedific realization of each function module ofthe data collector system was introduced, and texted this data collector system.(4)Through comparing several popular methods of software compensation intoday, the temperature compensation based on the interpolation of third order splineswas decided to adopt, and the traditional compensation method based on theinterpolation of third order splines was improved.(5)Combined with the successful development of data acquisition system, thestatic characteristic of sensor was calibrated, analysis of those calibrated data,temperature compensation of sensor was tested, by comparing the output signals bythe sensor based on the traditional interpolation of third order splines, the effect aboutimproved compensation method based on the interpolation of third order splines wasbetter.