直接姿態回授六軸機械手臂控制系統開發

Development of a Control System for Six-Axis Manipulators with Direct Pose Feedback

劉彥廷(Liu, Yen Ting)

指導教授 ： 雷衛台

國立清華大學/工學院/動力機械工程學系/碩士(2015年)

摘要

以史都華平台機構為基礎所開發之六維運動量測裝置(Six-Degree Motion Measuring Device, MMD)是具有六個量測維度之測量裝置，將此六維運動量測裝置之上板安裝於六軸機械手臂末端的工具端，下板固定於工件端時，可直接回授六軸機械手臂之姿態，進行六軸機械手臂之伺服運動控制。
本研究提出六軸機械手臂之直接姿態回授控制(Direct Pose Feedback Control, DPFC)，在其運動過程中，利用六維運動量測裝置量測工具之姿態，經機械手臂理想機構逆轉換得出各關節之實際機械座標，此實際機械座標與機械手臂關節編碼器所量出之機械座標間之差值來自機械手臂之連結誤差，將此差值回授至馬達伺服控制迴路做誤差補償，可消除機械手臂關節編碼器無法觀測到之連結誤差。
本論文提出之六軸機械手臂直接姿態回授運動控制由各馬達之伺服控制及整機之連結誤差補償控制構成，由於此方法完整保留原始之馬達伺服控制，因此極易整合於既有之機械手臂控制系統中，本論文另外實現六軸機械手臂之雙設定點運動控制(Twin-Setting-Points Motion Control, TPMC)，配合直接姿態回授控制，大幅提升了六軸機械手臂之定位及軌跡精度。

關鍵字

六軸機械手臂 ； 史都華平台 ； 直接姿態回授

並列摘要

The Six-Degree Motion Measuring Device (MMD) is based on the Stewart platform mechanism and provides six measuring degrees of freedom. The pose of the manipulator can be directly measured by the MMD and be fed back for the servo motion control, when the upper plate of the MMD is mounted on the end of the manipulator and the base is fixed on the workpiece side.
This research proposes a Direct Pose Feedback Control (DPFC) for a six-axis manipulator. During its motion control, the MMD is used to measure the pose of the tool. The actual machine coordinates are calculated after the ideal backward kinematic transform. The differences between actual machine coordinates and the machine coordinates measured by joint encoders are resulted from link errors of the manipulator. Feeding them back to the servo control loop of motors, the link errors not observable by the joint encoders can be eliminated.
Presented by this thesis, the direct pose feedback control of the six-axis manipulator consists of the servo control of each motor and link errors compensation control of the six-axis manipulator. Since this method keeps the original servo control loop intact, therefore, it is easy to integrate the method in the existing control system. Additionally, The Twin-Setting-Points Motion Control (TPMC) for the six-axis manipulator is also implemented in this thesis. Together with the direct pose feedback control, the positioning and contour accuracy of the six-axis manipulator are dramatically improved.

並列關鍵字

Six-Axis Manipulator ； Stewart Platform ； Direct Pose Feedback

參考文獻

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