Disturbance observer based small force detection for an ultrasonic motor with application to a surgical device

In this paper, an automatic office-based ear surgical device for the treatment of Otitis Media with Effusion (OME) which overcomes the disadvantages of the conventional surgical treatment is introduced. Since the device carries out the surgery automatically under the guidance of force sensing information, this information must be reliable so that the safety of the device can be ensured. Hence, a force detection method based on the disturbance observer is proposed in this paper. To overcome the disadvantages of the conventional disturbance observer, an advanced disturbance observer is designed and its stability is analyzed. Finally, the simulation study on the disturbance observer is carried out. The results show that the advanced disturbance observer can estimate the disturbance correctly and precisely.