- 學位論文
自適應六自由度同步控制混合式龍門機器人/工具機結合全方位探針/刀具中心點操縱於同機台複雜3D物件加工及驗證之應用
Adaptive Synchronous Control of Hybrid 6-DoF Gantry Robot Machine with Omni-Directional Touch Probe/Tool Center Point Maneuvering for On-Machine Complex 3D Object Machining and Verification Application
摘要
本論文研發雙驅動龍門式機器(DDGM)結合融合多軸機器人(HMAR) 俱高剛性、高精度融合刀具中心點(TCP)模式和無偏斜力(SFFMB)龍門同步設計。針對新的SFFMB 龍門同步設計，提出了新開發的主動/被動控制模型以防止龍門偏斜。推導出從軸和主軸之間的力比分配，其實驗結果顯示啟用SFFMB 龍門同步控制功能時，主/從軸線性馬達的驅動電流較低。即使在龍門軸有扭曲偏差時此功能仍可使機器平穩移動。這些設計方法目的在提升高速精度和性能，以縮短多自由度(DoF)機器的工作週期時間。對於HMAR與DDGM的發展有三個主要貢獻。首先，考慮偏斜力問題，提出了一種新的SFFMB 龍門同步設計，以防止龍門偏斜現象。其次，為了確保精確的全向線性移動，提出了一種新的融合TCP 模式，將座標轉換分離為獨立的平移和旋轉分量。第三，基於SFFMB 龍門同步策略及融合TCP 模式，提出了一種有效的校準方法以提高TCP 精度。因此DDGM 的HMAR 的主要設計概念如下所列: (1) 新型動態之主動/被動龍門同步控制設計，適用於絕大部份的龍門型機器。 (2) 獨立分離的6-DoF 龍門機械操縱設計，使座標轉換更簡單、更清晰，對於需要精確全向線性移動的應用非常有用。 (3) 不需要測量裝置的新TCP校準過程設計。 對於俱有高靈活性TCP 應用的全向線性移動，本論文介紹了自動全向式探針(ODTP)，包括俱有自適應調適結合最佳插值的複雜輪廓曲線並基於DDGM 的HMAR 的運動規劃。它被稱為”全向” 是因為在TCP 模式下的六自由度ODTP 始終可以和物件輪廓曲線維持法線方向。本論文提供了插值和運動規劃的新最佳解決方案，以解決物件複雜曲線的小線段問題。我們提出了一種維持最大加速度的演算法，使高階複雜輪廓軌跡由一群小線段組成且生成平滑而高效的3D 逆向工程物件。 綜觀以上結果產生的等速移動對於某些應用如塗膠、焊接和鐳射切割，均是非常重要以保持加工品質。本論文也透過以上結果結合物體的對稱性、擴展性和合成特性的利用以簡化逆向工程的進行過程。這些方法減少了探針檢測點所需的時間。 俱有全方位高靈活性TCP 功能其對腹腔鏡手術非常有用，腹腔鏡手術已成為微創手術的主流惟須考慮安全問題。本論文搭配前述技術成功開發了俱有自適應阻抗/順從能力的笛卡爾位置和力量控制，包括結合速度控制與刀尖端固定控制(EEFC)。本論文展示了力量控制下基於笛卡爾座標的目標點刀尖端定位，且不須使用/考慮反向運動學。此功能的優點在於可安全的將刀尖端移動到目標點，因為機械臂在移動過程中的路徑可被停止或改變。阻抗增益可根據移動軌跡條件自適應調整。因此，最終刀尖端可以達到預設目標點。基於順從控制加上力控制去輔助以易於操作機械臂其重力補償是一種必要技術，本文對此重力補償進行了解決。我們提出了一種基於向量投影概念的方法，計算一種能構建多自由度機器臂重力模型的一般解。我們還實驗性地展示了自適應阻抗/順從控制、速度控制和EEFC 的功能作用，這些功能作用在許多應用中非常有用，如腹腔鏡手術、向殘疾人餵食食物、工業錐形切割補償和去毛邊/拋光等等應用。 本論文針對所研究的理論和技術推出衍生的可能應用, 我們發展/介紹了兩種不同類型的腹腔鏡系統。第一代腹腔鏡系統具有順應性效果,包括輔助腹腔鏡手術的自適應阻抗和速度控制. 第二代腹腔鏡系統稱為”機器人柔性腹腔鏡系統(RFLS)”, 俱有直觀可操作性的輔助腹腔鏡手術系統。去毛邊/拋光工作也是本論文開發俱高挑戰的應用例, 其砂輪磨削中心點概念及技術(FCP)是此去毛邊/拋光應用的關鍵技術所在。 以上研究/實驗的實現和驗證都以影像成功的呈現。
並列摘要
This dissertation develops a high-stiffness, high-precision, hybrid tool center point (TCP) mode and a skew force free model based (SFFMB) synchronous gantry-type design for a Hybrid Multi-Axis Robot (HMAR) with Dual Drive Gantry-type Machine (DDGM). For the new SFFMB synchronous gantry-type design, newly developed active/passive control models are presented to prevent gantry skew. The force ratio between the slave and master axes is generated, and experimental results show that the driving currents for the master/slave linear motor axes are lower when the SFFMB synchronous control function is enabled. This function makes the machine move smoothly even when deviations from squareness occur. These design approaches aim to improve the accuracy and performance at high speed to reduce the working cycle time for a machine with multiple degrees of freedom (DoF). For the developments of the HMAR with DDGM, there are three major contributions to the scientific research communities. Firstly, by considering the skew force issue, a new SFFMB synchronous gantry-type design is proposed to prevent gantry skew phenomenon. Secondly, to ensure exact omni-directional linear movement, a novel hybrid TCP mode is proposed to decouple coordinate transformations into individual translation and rotation components. Thirdly, based on the SFFMB synchronous control strategy and the hybrid TCP mode, we propose an effective calibration method to enhance the TCP accuracy. The main design concepts of the HMAR with DDGM are described as follows. (1) A new and dynamic active/passive synchronous control design for a machine with almost-parallel gantry axes. (2) A decoupled 6-DoF gantry manipulator design, which makes the coordinate transformations much simpler and clearer and is very useful for applications that require exact omni-directional linear movement. (3) A new TCP calibration process design that does not require measuring device. For the omni-directional linear movement with the high flexibility TCP applications, automated Omni-Directional Touch Probe (ODTP) including adaptive tuning of the complex contour curve with optimal interpolation and motion planning based on a HMAR with DDGM are presented. It is called an “Omni-Directional” because the 6-DoF ODTP in TCP mode can always maintain normal direction towards the object contour curve. The new optimal solutions of the interpolation and motion planning are provided to tackle the small segments issues for a complex curvature object. We present an algorithm to maintain maximum acceleration, so that it generates smooth and efficient 3D reverse engineering object in a higher order complex contour trajectory composed of piecewise small segments. As a result, the constant moving speed is very important to certain applications, such as gluing, welding, and laser cutting, to preserve quality processing. Based on the results, the utilization of object symmetry, extension and synthesis properties to simplify the process of performing reverse engineering is described. These methods reduce the time required for the touch probe to detect the object surface points. The omni-directional with the high flexibility TCP functions are very useful for the laparoscopic surgery which becomes mainstream in minimally invasive surgery. For this function, the safety issues have to be considered. In this dissertation, the Cartesian position and force control with adaptive impedance/compliance capabilities for a humanoid robot arm including velocity control incorporate with End-Effector Fixation Control (EEFC) is successfully developed based on the technology mentioned earlier. We demonstrate the end-effector positioning to reach the target point in Cartesian coordinate frame based on force control without solving the inverse kinematic problem. The advantage of this function is obvious in moving the endeffector to go to the target point safely because the robot arm moving trajectory can be stopped or modified during the movement. The impedance gain can be adjusted adaptively according to the moving trajectory conditions. As the result, the end-effector can reach the presetting target point. The compliance function with force control for auxiliarily easiness in manipulating robot arm is desirable, in which the gravity compensation is a necessary technique. The solutions are included for resolving these problems and described in this thesis. We propose a method that based on the concept of vector projection to calculate a general solution which can construct a gravity model of multi-DoF robot arm. We also have experimentally demonstrated the effect of adaptive impedance/compliance control, velocity control and EEFC which are useful in many applications, such as laparoscopic surgery, feeding food to the impaired person, industrial taper cutting compensation and deburring/polishing etc. Snapshots of potential applications based on the technologies developed in this thesis are included. Two different types laparoscopic system are developed/presented in this dissertation. The type I laparoscope system has compliance effect including adaptive impedance and velocity control for assistive laparoscopic surgeryng. The type II laparoscope system is called “Robotic Flexible Laparoscope System (RFLS)” with intuitive maneuverability for assistive laparoscopic surgeryng. Also, the deburring/polishing tasks are highlevel challenge applications, which are developed in this dissertation. The concept and technology of Flute/Grinding Center Point (FCP) is the key point for these deburring/polishing applications. The experimental implementation is successfully demonstrated with the video clip.