Shear effect elimination on force measurement with flexible piezo-resistive sensor during hand manipulation

Flexible sensing resistors are satisfied for general-purpose applications in recording interactive force during hand manipulation. However, FSR sensors are considerably sensitive to shear. In this paper, shear effect of a Tekscan FlexiForce A401 sensor was investigated with a reformed offset runout detection instrument. Sensor output increased caused by shear stress is significant with normal load decreased and shear stress increased. The calibration of FSR output is necessary because shear effect is not sensitive and removed instantly. Considering the linearity of shear stress and normal load, a regression fit demonstrated the relationship between FSR sensors output and combination of normal load and shear stress. With this fit model, the calibrated signal of force measured by FSR Sensor was more accurate for reviving interactive force during hand manipulation.