基於人工勢場之自走車避障策略之實現

On the Implementation of Collision Avoidance of a Wheeled-robot using Artificial Potential Field Approach

楊甄寧(Chen-Ning Yang)

指導教授 ： 陳建祥

國立清華大學/工學院/動力機械工程學系/碩士(2013年)

摘要

本文使用輪型機器人結合雷射測距儀取得的環境資訊，將人工勢場法實現於避障路徑規劃。人工勢場法是將機器人視為一質點，其運動環境視為一虛擬的勢能場，整個區域內的障礙物對機器人產生斥力場，目標點產生引力場，依據人工勢能場的方向及大小變化和最速下降法的步長選取方式，並加入了移動障礙物的判斷，規劃質點從高勢能處向最低勢能處移動的路徑，進行機器人移動速度與方向的控制，使機器人能遠離障礙物向目標點前進。
置於輪型機器人上的電池除了要供應機器人本身的電源，同時也需要供應筆記型電腦、雷射測距儀等周邊實驗器材的電源，耗電量非常大，因此電池的充電問題是一大考量，本文亦考慮返航充電之功能，經過定位計算，回到指定位置，透過設計的充電機構導正進行充電。
本文針對人工勢場法應用於輪型機器人運動的侷限性與問題提出改善，在實驗中，輪型機器人能夠判斷障礙物的動靜，並依照人工勢場法分析的合力來避開障礙物，向目標點前進，並以U字型凹槽(充電設備放置處)進行校正對準動作，返回充電設備自行充電。

關鍵字

人工勢場法 ； 避障 ； 輪型機器人 ； 雷射測距儀

並列摘要

The objective of this thesis is performing path planning to avoid obstacles by Artificial Potential Field Method. The experimental system consists of a wheeled robot, a scanning laser range finder, and a notebook. In Artificial Potential Field Method, the mobile robot is viewed as a particle, and the environment as a virtual potential field. In the moving area, obstacles produce repulsive force, and the target produces attractive force to the mobile robot. According to the environment information obtaining from scanning data, we can determine whether the obstacle is moving or not, and also calculate the resultant force of all obstacles in setting range and the target by Artificial Potential Field Method. By analyzing the resultant force calculated by Artificial Potential Field Method and choosing step size by Steepest Descend Method, we can control the motion of the robot so that the mobile robot can avoid obstacles and moving toward the target.
In this thesis, the robot can determine the status of obstacles and following the motion strategy safely avoid obstacles, and move toward the target. After reaching the target, the robot moves toward the preset U-shaped object (charger place) by alignment and being recharged automatically.

並列關鍵字

Artificial Potential Field Method ； Wheeled robot ； Obstacle avoidance ； Scanning laser range finder

參考文獻

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