牙髓病根管治療機器人之定位控制

Abstract

牙髓病根管治療的技術已經發展了許多年，然而治療成功與否迄今仍然深受牙醫師本身的經驗所影響。先進根管治療之研究旨在發展電腦輔助系統及根管治療微小機器人，提升根管治療手術的品質及成功率。本研究之目標為發展此微小機器人之定位控制。 本研究分為三個主軸，分別為超音波馬達致動平台設計、位置感測器以及控制器的設計。以四個超音波馬達建構四軸致動平台，藉由四軸的組合運動，可以達到X方向以及Y方向的運動，也可以達到α及β兩個角度的調整，如此達到根管治療過程中所需的各種動作。位置感測器則以增量式編碼原理為主軸，輔以邊際電容感測或磁阻感測器，量測單軸位移，分別獲得四軸位移之後，即可透過計算，獲得機器人上所裝載之治療器具的位移量及所轉動的角度。而且設計了模糊控制器，以從事此微小機器人之定位控制。實驗使用了個人電腦裡的LabVIEW圖控軟體以及NI-sbRIO 9631介面卡，透過模糊控制器，在1mm的步階命令下，上升時間小於52ms，可迅速定位；機器人定位的穩態誤差小於0.072mm，與人為進行根管治療手術之常見誤差0.1mm相比，已有較高的精度。

The endodontic technology has been developed for many years in dentistry. However, treatment success still heavily depends on experience of dentists. Therefore, the present study aims to enhance the clinical quality and increase cure rates of endodontic technology by developing a computer-aided system and an endodontic microrobot. This study develops the positioning control for the endodontic microrobot. This study can be divided into three main parts, which include designs of an ultrasonic motor (USM) actuator stage, position sensors, and controllers. First, the USM stage constructed by four USMs can not only realize the movement of X direction and Y direction, but also α and β rotations, such that the microrobot can achieve any motion required in the endodontic treatment process. On the other hand, position sensors are designed based on incremental encoder principle with a readout head, which is made of fringe capacitors or magneto-resistive sensors. After four USM displacements are measured, the displacement and rotation angle of the therapeutic apparatus loaded on the microrobot can be calculated. Finally, a fuzzy controller is designed in order to carry out positioning control of this microrobot. In experiments, a LabVIEW software in PC and a NI-sbRIO9631 interface card are used. By means of the fuzzy controller, the robot can be positioned quickly. The rise time of 1mm step response is less than 52ms, and the steady-state error in positioning is less than 0.072mm. Compared with the human 0.1mm in common endodontic surgery, the present microrobot has higher precision.