A microcontroller-based self-calibration technique for a smart capacitance angular-position sensor

Abstract—A self-calibration technique for capacitive position sensors, based on the use of a microcontroller is presented. This technique offers a good trade-off between the memory size of the microcontroller and the algorithmic complexity. The application of this technique for self-calibration of the inaccuracy caused by the geometrical errors and pattern errors in a smart capacitive angular-position sensor is discussed. This self-calibration tech-nique doesn’t need any accurate reference. Experimental results show that the self-calibration is relatively effective in reducing the influences of the geometrical errors and pattern errors of the sensor. The reduction of the inaccuracy of the smart capacitive angular-position sensor amounts to more than a factor of two. Index Terms — Calibration, capacitive sensor, multiple elec-trode, position measurement, self-calibration. I