自走車影像伺服動態定位系統研製

本文發展出一套簡單且有效率的影像定位方法，只須使用兩具影像感測器及數個固定在運作區間的標竿，即可動態控制自走車的相對方位。首先將兩具影像感測器分別安裝於自走車前方兩組由伺服馬達所驅動的轉盤上，當自走車行進時，兩具可控制轉向的影像感測器會隨時自動對準最近的兩支固定標竿，此時伺服馬達所屬的控制器會回傳自走車前向及影像光軸之間的夾角信號給自走車主控制器，由主控制器整合兩組影像資訊，利用座標轉換及適應類神經控制法則，即可將自走車控制於預定的路徑上。為了驗證本文所提自走車動態定位方法的有效性，吾人設計了一個比較實驗，讓自走車以往復路徑規劃方式操作在完全覆蓋的情況下。實驗結果顯示，本文所設計定位方式的精確度比其他以電子羅盤及全球衛星定位系統作為感測方式的系統佳，符合工業使用標準。

關鍵字

割草機器人；影像伺服；路徑規劃

並列摘要

This paper proposed a novel control scheme for dynamic positioning of mobile robot. With an imaging-based surveying method, the positions of the mobile robot relative to the working space can be located by utilizing two vision sensors and some target poles. The robot can measure the distances to two fixed target poles by controlling the optical axes of two rotatable on-board vision sensors to aim at the target poles respectively, and acquires the angles of the intersections between the longitudinal axis of the robot and optical axes of the sensors. After extracting the object images, the 2-D geometric relation between the target objects and the robot can be described by coordinate transformation. Based on this geometric information and path planning, an adaptive neural sliding mode control (ANSMC) algorithm can be derived by the Lyapunov stability theory for the Microcontroller (Arduino-MEGA) to produce the control command for keeping the mobile robot on the planned path. For verifying the performance of the proposed strategy, a reciprocal path planning for mobile robot was carried out to achieve fully coverage of working space. The experiment results indicated that our method outperforms the methods based on a compass/GPS sensors. The maximum error between the estimated location and the real location is only about 5 cm per 10 meters, which meets the standard for engineering applications.

並列關鍵字

dynamic positioning ； vision-servo ； autonomous robot

參考文獻

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國際替代計量

自走車影像伺服動態定位系統研製

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