機械手在特定路徑之可操控性分析與應用

Abstract

這篇論文在探討六軸機械手之可操控性，由手端位置與方向的控制配合操控性橢球和操控性指數理論將機械手之操控能力量化，這對於機械手的任務規劃與控制是相當有幫助的，由模擬的結果顯示所提出的方法可以有效規劃六軸機械手的控制軌跡，使其達到最佳的運動狀態。 在分析的例子□，由ADAMS之速度分析證明整體操控性指數可有效的衡量機械手之控制能力，而位置操控性指數與方向操控性指數可以提供更細部的資訊協助改善機械手的操控能力。根據分析之圖表可以事先規劃並產生有益且平滑的工作路徑，避開操控性較差的區域，讓機械手在操控性較好的工作區域以獲得較穩定而精確的運動效果。若工作路徑無法完全避開操控性較差的區域，則本研究成果建議在操控性較差的位置可將機械手手端的方向作小幅變動，或者是更動工作區域使機械手在操控性較好的平面進行工作。 本研究成果可應用在外科手術的醫療輔助自動化系統，將手術所造成的傷害減至最低並增加病人的保障。

The concept of manipulability measure of a six-joint manipulator is discussed. This is a measure of manipulating ability of a six-joint manipulator in positioning and orienting the end-effectors of the robot. The manipulability ellipsoids and manipulability index algorithms is used to quantify the ability of a manipulator. It will be beneficial for control of manipulator and for task planning if we have a quantitative measure of manipulating ability of a robot arm in positioning and orienting the end-effectors. A simulation study shows the effectiveness of the proposed method in controlling a manipulator with six degree of freedom. From the case studies, we can conclude that the total manipulability quantity value servers as a useful index of robot controllerbility, as confirmed by the velocity analysis with ADAMS. But each of the position and orientation Jacobian can provide more detail information that singularity events will be induced. Based on the singularity or manipulability quantitative diagram provided by this study, an efficient and smooth path can thus be planned and generated. If the working path could be prescheduled to avoid the singularities, the manipulator can full fill its task at the predicted working space successfully. Otherwise, we suggest to change orientation of the end-effectors near the singularities or adjust the working planes that have less or without singularities. The results of the research can be further applied to the automatic surgery operation, and it can minimize surgical injury and increase patient’s safety.