果實採收機器人之複合式腱驅動機構設計

Abstract

因應全球農業人口短缺及老化的問題，許多科學家都在著手研究採收機器人之相關議題，希望藉此解決目前農業的人口問題。但目前研究學者所開發設計的採收機器人尚存在著一些問題，例如: (1) 過大的體積與重量可能導致農作物的損害。(2) 機構過重導致制動器需要消耗更多能源來驅動採收手臂。(3) 採收手臂的避障功能不顯著。而這些不利因素將導致採收作業的進行更加困難。因此，本論文提出一新型草莓採收機械手臂，透過複合式關節機構來達到減少機械手臂的體積與重量，同時也能提供維持手臂平衡所需的扭矩，再藉由模仿人類手臂關節機構設計以及冗自由度的關節配置來達到較高的靈活度，以突顯其避障功能優於其他傳統的採收機械手臂。此外，末端的採收夾具利用一觸發機構來彌補複合式繩索驅動的剪斷力不足，也能保留其減少體積與重量的優點。最後透過定義一目標函數，將其對冗自由度參數(RA)進行最佳化分析，並找到最節省扭矩消耗的採收姿態，以及透過Null Space Method的冗自由度避障理論進行模擬，使本論文所提出的採收手臂達到避障採收的功能。

With the global agricultural population shortage and aging, many scientists are working on the issue of harvesting robots, hoping to solve the current population problem of agriculture. However, there are still some problems in the harvesting robots developed by the research scholars, such as: (1) excessive size and weight may cause damage to fruits. (2) the mechanism is too heavy lead to the motor need to consume more energy to drive the harvest arm. (3) the function of obstacle avoidance of robot arm is not significant. And these unfavorable factors will lead to more difficult harvesting operations. Therefore, this paper proposes a new type of strawberry harvesting arm, by means of the complex-mechanism-design to achieve the reduction of the size and weight of the arm, but also to provide the necessary torque to maintain robot arm balance. By imitating the human arm design and setting the redundant joint to achieve a higher degree of flexibility to highlight its obstacle avoidance function is better than other traditional harvesting arm. In addition, the end-effector is driven by a trigger mechanism to make up the insufficient of the shear force of cable driven , but also to retain its advantages of reducing the volume and weight. Finally, by defining an objective function, optimizes the degree of redundancy (RA) and finds the robot arm postures that save the most torque, and simulates the obstacle avoidance function by Null Space Method, to prove that the harvesting arm is proposed to achieve the function of obstacle avoidance.