Research On Compensation For Hysteresis Of Macromolecular Humidity Sensor

The macromolecular humidity sensor is an important device to measure the humidity which has been widely used in the field of industry,agriculture,meteorology,national defense,science research,and so on.From the current view,the good performance such as high-precision,high-stability and fast-response represent the developing direction of the new humidity sensor.But the nonlinear hysteresis characteristic which demonstrates a multi-valued mapping exists in the process of the macromolecular'measurement,and limits the increase on humidity measurement accuracy.At present the domestic research on hysteresis is mainly concentrated on the model and control of the piezoelectrics,and there is little research on hysteresis of the sensor.The research on compensation for hysteresis of the sensor usually adopt the method of interpolation and polynomial fitting which can't totally meet the compensation precision.For this reason,an embedded smart macromole-cular humidity sensor is designed,and the following main results are obtained:1.According to the resemblance between the segmented linearity of hysteresis and T-S fuzzy modeling principle,a method is presented which model the dynamic hysteresis of the macromolecular through the T-S fuzzy modeling principle.The results of simulation show that the model is effective through approach and predicting to the sampling data,and has the higher precision.2.Based on the model,the inverse model is built and put behind the compensated object in order to compensate for the nonlinear hysteresis characteristics.The results of simulation show that is a good method to resolve the nonlinear hysteresis characteristics and improve the accuracy of measurements.3.According to the macromolecular humidity sensor's requirement of real-time measurement and the principle of intelligently compensation for the nonlinear hysteresis characteristics,we transplant the embedded real-time system ofμC/OS-Ⅱinto the hardware platform(FFT-S3C2410) which is based on the 32-bits ARM microprocessor S3C2410,and combine with the software platform(ARM ADSv1.2) to design an embedded smart macromolecular humidity sensor which has the following functions:⑴Real-time collection and analysis the output voltage signal of humidity sensor.⑵Carrying on a series of data processing to the voltage signal.⑶Real-time display the data which has been processed on the TFT-LCD.