Gain Tuning Method to Improve Sensor’s Accuracy and Resolution

Abstract

Sensing of physical quantities is often accompanied by generation of periodic error signals. Especially in the case of rotary type sensors, periodic error signals are difficult to be avoided. In this paper, we present a method to compensate periodic error signals by gain tuning in multiple pick-up sensors. A mathematical model of the periodic error signal and a method to compensate the error is presented. It is shown that gain adjustment in a minimum of three pick-ups is needed to compensate any frequency component of the error signal. Minimum number of pick-ups needed to compensate multiple frequency components of the error signal is also derived. The method is successfully demonstrated on simulated and experimental examples, where one and two frequency components of the error signal are successfully compensated. Reduced periodic error increases the sensors accuracy and allow higher resolution for digital sensors.