scholarly journals On the Design of Underactuated Finger Mechanisms for Robotic Hands

Author(s):  
Pierluigi Rea
10.5772/56479 ◽  
2013 ◽  
Vol 10 (10) ◽  
pp. 340 ◽  
Author(s):  
Anna Lisa Ciancio ◽  
Loredana Zollo ◽  
Gianluca Baldassarre ◽  
Daniele Caligiore ◽  
Eugenio Guglielmelli

2011 ◽  
Vol 08 (04) ◽  
pp. 761-775 ◽  
Author(s):  
ZHIXING XUE ◽  
RUEDIGER DILLMANN

Grasping can be seen as two steps: placing the hand at a grasping pose and closing the fingers. In this paper, we introduce an efficient algorithm for grasping pose generation. By the use of preshaping and eigen-grasping actions, the dimension of the space of possible hand configurations is reduced. The object to be grasped is decomposed into boxes of a discrete set of different sizes. By performing finger reachability analysis on the boxes, the kinematic feasibility of a grasp can be determined. If a reachable grasp is force-closure and can be performed by the robotic arm, its grasping forces are optimized and can be executed. The novelty of our algorithm is that it takes into account both the object geometrical information and the kinematic information of the hand to determine the grasping pose, so that a reachable grasping pose can be found very quickly. Real experiments with two different robotic hands show the efficiency and feasibility of our method.


Meccanica ◽  
2015 ◽  
Vol 50 (11) ◽  
pp. 2767-2780 ◽  
Author(s):  
G. Palli ◽  
S. Pirozzi ◽  
C. Natale ◽  
G. De Maria ◽  
C. Melchiorri

Author(s):  
Giorgio Grioli ◽  
Manuel Catalano ◽  
Emanuele Silvestro ◽  
Simone Tono ◽  
Antonio Bicchi
Keyword(s):  

2017 ◽  
Vol 20 (1) ◽  
pp. 104 ◽  
Author(s):  
М А Al Akkad
Keyword(s):  

Проведен анализ проблемно ориентированного захвата, учитывающий задачи сокращения сложности и достижения гибкого и стабильного захвата. Для регулировки положения манипулятора и объекта в процессе реализации алгоритма захвата используется вектор нормали, определяющий ориентацию руки. Для описания объекта используется представление переменной шириной пульса (ПШП), при этом значения углов ориентации трехмерной модели преобразуются в величины ширины пульса. Для выбора наиболее подходящего расположения и формы руки при захвате применяется циклический метод сопоставления объекта (ЦСО), использующий сплайны трехмерной модели объекта и алгоритм адаптации кривизны. Эксперименты показали, что анализ движений захвата возможен независимо от его силы; кроме того, следует принимать во внимание связь между суставами пальцев. Эксперименты также показали, что координация между двумя руками, основанная на методе, использующем угол наклона нормали, предлагает достаточно быстрое и точное решение для широкого спектра применений. Важным результатом исследования также является вывод соотношения точности захвата и угла ориентации и яркости объекта. Конечная цель исследования заключается в интеграции управления кистью и остальными частями руки как единым целым; предотвращении столкновений и достижении точной координации, позволяющей использовать роботизированные манипуляторы в любом приложении, где работа предполагает определенный ряд задач: спасательные работы, производство, медицинские операции и производство протезов.


2021 ◽  
Vol 8 ◽  
Author(s):  
Zubair Iqbal ◽  
Maria Pozzi ◽  
Domenico Prattichizzo ◽  
Gionata Salvietti

Collaborative robots promise to add flexibility to production cells thanks to the fact that they can work not only close to humans but also with humans. The possibility of a direct physical interaction between humans and robots allows to perform operations that were inconceivable with industrial robots. Collaborative soft grippers have been recently introduced to extend this possibility beyond the robot end-effector, making humans able to directly act on robotic hands. In this work, we propose to exploit collaborative grippers in a novel paradigm in which these devices can be easily attached and detached from the robot arm and used also independently from it. This is possible only with self-powered hands, that are still quite uncommon in the market. In the presented paradigm not only hands can be attached/detached to/from the robot end-effector as if they were simple tools, but they can also remain active and fully functional after detachment. This ensures all the advantages brought in by tool changers, that allow for quick and possibly automatic tool exchange at the robot end-effector, but also gives the possibility of using the hand capabilities and degrees of freedom without the need of an arm or of external power supplies. In this paper, the concept of detachable robotic grippers is introduced and demonstrated through two illustrative tasks conducted with a new tool changer designed for collaborative grippers. The novel tool changer embeds electromagnets that are used to add safety during attach/detach operations. The activation of the electromagnets is controlled through a wearable interface capable of providing tactile feedback. The usability of the system is confirmed by the evaluations of 12 users.


Author(s):  
Raymond Guo ◽  
Vienny Nguyen ◽  
Lei Niu ◽  
Lyndon Bridgwater

There has been continuous research and development to add more actuators into robotic hands to increase their dexterity. However, dexterous hands require complex control and are more costly to build. Therefore, many researchers and commercial enterprises have begun developing under-actuated robotic hands with fewer actuators and passive mechanical adaptation to not only reduce complexity and cost, but to also achieve better grasp performance in unstructured settings. This paper presents the design and analysis of the Valkyrie hand — a four fingered, tendon-driven, and under-actuated robotic hand that balances dexterity and simplicity with total 14 joints, and six degrees of actuated freedom. A derivation is provided of general dynamic and static equations for the analysis of a tendon driven mechanism, based on Euler-Lagrange formulation. The equations were used to evaluate the design parameters’ impact on the hand grasp shape and closing effort, and also validated against a design case study.


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