融合雷射掃描及視覺資訊之TEB演算法應用於無人搬運車防碰撞策略開發
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2023
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隨著無人搬運車(AGV)在倉儲、物流和製造業等領域的普及，使用機器人在運輸和操作物品方面的效率和安全性受到越來越多的關注。然而，當AGV操作場域複雜或不確定環境時，其運動控制和防碰撞設計仍然存在挑戰。為了實現避障，本論文採用Timed-Elastic-Band (TEB)演算法，在多個選擇路徑中選擇最佳路徑，並使用動態控制策略實現平順移動。此外，針對雷射掃描無法有效偵測之空間障礙物，本論文整合影像辨識來輔助TEB演算法的防碰撞策略，以增強無人搬運車進行導航任務的運動控制和避障能力。透過攝影機即時偵測AGV前方的環境影像，並利用機器學習技術識別空間障礙物的相對位置資訊，透過座標轉換將空間障礙物座標投影在代價地圖上，使TEB局部路徑規劃器可以將其納入計算避障路徑。本論文所開發的防撞策略先於ROS Stage模擬驗證後再將其實現於AGV平台進行實車驗證，透過融合影像偵測資訊與雷射掃描資訊的TEB避障演算法，經由實驗結果驗證能在導航過程中安全完成障礙物閃避。本論文採用之AGV平台及測試場域與業界緊密合作，顯示所提出防撞策略已成功整合於導航軟體架構與實際產業上之需求潛力。
As automated guided vehicles (AGV) become more prevalent in fields such as warehousing, logistics, and manufacturing, their efficiency and safety in handling and transporting goods are becoming increasingly important. However, challenges in terms of motion control and collision avoidance capabilities still exist for AGV while operating in complex or uncertain environments. As such, to enhance the motion control and collision avoidance capabilities of AGV, this thesis proposes an effective strategy based on the Timed-Elastic-Band (TEB) algorithm with the aid of visual recognition. To avoid possible collision, the TEB algorithm is to choose the optimal path from multiple candidate paths and then the dynamic control can be utilized for smooth motion control of AGV. In addition to the obstacles detected from 2D laser scanning, the proposed strategy uses a camera to capture the front environment of the AGV and uses machine learning techniques to recognize the camera coordinate of the spatial obstacle in real time. Thus, such a spatial obstacle can be projected onto a cost map for the TEB path planner to determine the collision-free path. With consideration of the kinematics and dynamics constraints of our AGV, the collision avoidance strategy presented in this study is firstly verified in Ros Stage simulation. Further, the experimental evaluation for automatic navigation process combined with global path planning and TEB local path planner is carried out. Through the TEBobstacle avoidance algorithm fusing visual information and laser scanning information, experimental results verified that obstacles can be safely avoided during the navigation process. The AGV platform and test field used in this thesis are in close cooperation with the industry, showing that the proposed collision avoidance strategy has feasible potential integrated into the navigation software architecture and the demand of actual industry.
As automated guided vehicles (AGV) become more prevalent in fields such as warehousing, logistics, and manufacturing, their efficiency and safety in handling and transporting goods are becoming increasingly important. However, challenges in terms of motion control and collision avoidance capabilities still exist for AGV while operating in complex or uncertain environments. As such, to enhance the motion control and collision avoidance capabilities of AGV, this thesis proposes an effective strategy based on the Timed-Elastic-Band (TEB) algorithm with the aid of visual recognition. To avoid possible collision, the TEB algorithm is to choose the optimal path from multiple candidate paths and then the dynamic control can be utilized for smooth motion control of AGV. In addition to the obstacles detected from 2D laser scanning, the proposed strategy uses a camera to capture the front environment of the AGV and uses machine learning techniques to recognize the camera coordinate of the spatial obstacle in real time. Thus, such a spatial obstacle can be projected onto a cost map for the TEB path planner to determine the collision-free path. With consideration of the kinematics and dynamics constraints of our AGV, the collision avoidance strategy presented in this study is firstly verified in Ros Stage simulation. Further, the experimental evaluation for automatic navigation process combined with global path planning and TEB local path planner is carried out. Through the TEBobstacle avoidance algorithm fusing visual information and laser scanning information, experimental results verified that obstacles can be safely avoided during the navigation process. The AGV platform and test field used in this thesis are in close cooperation with the industry, showing that the proposed collision avoidance strategy has feasible potential integrated into the navigation software architecture and the demand of actual industry.
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無人搬運車, 空間障礙物件偵測, 雷射視覺融合, 路徑規劃, 防碰撞, AGV, spatial object detection, laser-visual fusion, path planning, collision avoidance.