Correction of temperature and acceleration effects on MEMS gyro output signals /

Ali, Muhammad
The scope of this thesis is to study the effects of temperature and acceleration on a MEMS gyroscope and present a workable solution to compensate these errors using various techniques. Compensation for errors is implemented considering the output bias data of the gyroscope. The study also provides comparison of these various techniques, namely Polynomial Curve fitting and Neural Networks. In addition, Moving Average Filtering is used as an auxiliary technique. The study provides novelty of compensating both the factors based on empirical data which is not done before this study. The thesis also discusses the hysteresis present in the gyroscope output data due to change in temperature slope (ascending and descending) and provides a solution to compensate this error. The relation between the magnitude of hysteresis and temperature range is formulated. The methodology adopted in this study is to use existing techniques with some modifications and to compensate different types of errors collectively. The techniques are implemented on data acquired from some commercial sensors, namely ADIS16488, ADXRS450, and XSENS MTi-10. In terms of bias instability temperature compensation can achieve up to 20% improvement (from 33.5⁰/hr to 26.5⁰/hr) in ADXRS450 and 50% improvement (from 12.24⁰/hr to 6.12⁰/hr) in XSENS MTi-10 sensors’ data. By including hysteresis compensation, the improvement can be increased to 28% (from 34.2⁰/hr to 26⁰/hr) and 57% (from 10.8⁰/hr to 4.68⁰/hr) for ADXRS450 and XSENS MTi-10 respectively. Compensating temperature, acceleration and hysteresis at the same time can improve the bias instability of XSENS MTi-10 up to 70% (from 16.56⁰/hr to 5.04⁰/hr). The compensation of these factors also reduces the rate random walk significantly, which is evident from Allan variance plots. The integration times can be improved 4 times for ADIS16488 and ADXRS450 and 8 times for XSENS MTi-10. The offset in the gyroscope output can be reduced 50 times (from 0.05⁰/sec to 0.001⁰/sec) by integrated compensation as compared to 10 times (from 0.05⁰/sec to 0.005⁰/sec) by conventional temperature compensation in the XSENS gyroscope data. Integrated compensation of temperature, acceleration and hysteresis results in better performance as compared to the conventional method of compensating only for temperature, providing a more accurate and error free data.
Citation Formats
M. Ali, “Correction of temperature and acceleration effects on MEMS gyro output signals /,” M.S. - Master of Science, Middle East Technical University, 2014.