Characterization of hysteresis in resistive bend sensors

Abstract

© 2017 IEEE. Sensing of finger joint rotation can be difficult due to the hand's many degrees-of-freedom within a small space. The low profile and lightweight of resistive bend sensors make their use in measuring joint rotation an option. Certain properties of the bend sensors have been investigated, however investigation of the effect of hysteresis when bending and straightening the sensor has not been investigated. In this study, two inch resistive sensors were bent from 0° to 90° and back to 0° while measuring the voltage output. Three calibration models were fitted to the measured data and used to determine the sensor's accuracy and hysteresis effects. Both the quadratic and cubic fits demonstrated strong non-monotonic behavior at low bend angles. Using the exponential model, a hysteresis effect of 9.2% was observed. Accuracy at low bend angles improved by approximately 5° when the effect of hysteresis was considered.