Built-In High Accuracy Torque Sensing For Harmonic Drive Gears

Abstract

In the case of harmonic drive gears the load torque can be sensed from a flexible part of the gear. A method by using strain gages was proposed, but is not widely utilized due to insufficient accuracy and residual ripple. We analyze the errors and propose arrangement of the strain gages which improves both the accuracy and the ripple of the torque sensing to 1% level of the gear torque capacity.