In-hand recognition and manipulation of elastic objects using a servo-tactile control strategy
In-hand recognition and manipulation of elastic objects using a servo-tactile control strategy
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DOI：
10.1016/j.rcim.2017.03.002
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发表时间：
2017-12-01
影响因子：
10.4
通讯作者：
Torres, F.
中科院分区：
文献类型：
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作者：
Delgado, A.;Jara, C. A.;Torres, F.
用机器人手抓取和操纵物体在很大程度上取决于要使用的物体的特征。特别是，柔软性和变形性等特征在操作任务中至关重要。实际上，当操纵物体时，手指的位置和由机器人手施加的力必须适应所引起的变形。对于未知对象，通常需要先前的识别阶段来获得对象的特征，并且必须根据该识别阶段来调整操作策略。为了在操纵任务中获得精确的控制，通常需要并执行复杂的对象模型，例如使用有限元方法。然而，这些模型需要一个完整的离散化的对象，他们是耗时的操作任务的性能。为此，本文提出了一种新的控制策略，基于最小弹簧模型的对象，并用于控制的机器人手。本文还提出了一种自适应伺服控制方案，可用于手操纵任务的可变形物体。触觉控制基于在接触点处实现并保持力值，该力值根据对象柔软度（在初始识别阶段中估计的特征）而改变。
Grasping and manipulating objects with robotic hands depend largely on the features of the object to be used. Especially, features such as softness and deformability are crucial to take into account during the manipulation tasks. Indeed, positions of the fingers and forces to be applied by the robot hand when manipulating an object must be adapted to the caused deformation. For unknown objects, a previous recognition stage is usually needed to get the features of the object, and the manipulation strategies must be adapted depending on that recognition stage. To obtain a precise control in the manipulation task, a complex object model is usually needed and performed, for example using the Finite Element Method. However, these models require a complete discretization of the object and they are time-consuming for the performance of the manipulation tasks. For that reason, in this paper a new control strategy, based on a minimal spring model of the objects, is presented and used for the control of the robot hand. This paper also presents an adaptable tactile-servo control scheme that can be used in in-hand manipulation tasks of deformable objects. Tactile control is based on achieving and maintaining a force value at the contact points which changes according to the object softness, a feature estimated in an initial recognition stage.