Harmonic Drive with a Built-in Torque Sensor and Its Application to Torque Control
Minoru Hashimoto, Hideki Hirabayashi*, and Toshihide Kiyosawa*
Faculty of Engineering, Kagoshima University
* Harmonic Drive System Inc.
In this paper, first a method of torque measurement using elasticity contained in harmonic drive system is outlined. This method of torque measurement does not require changing the structure of the driving system nor inserting a new elastic body for torque measurement. Here, a configuration method of strain gauge for measuring the true torque based on the finite-element method analysis of the flexspline, an elastic clement in the harmonic drive, is proposed. Then, the properties of this torque sensor are experimentally verified. Finally, as a case of application, non-linear friction attributable to the harmonic drive is compensated by torque control using the torque sensor mentioned here, showing an improvement in performance of motion control.