Regeneration of natural grasp prehensions on underactuated robot‐hand through kinaesthetic guidance

2017 ◽  
Vol 53 (5) ◽  
pp. 314-316
Author(s):  
R. Chattaraj ◽  
S. Khan ◽  
D.G. Roy ◽  
B. Bepari ◽  
S. Bhaumik
Author(s):  
Hun-Keon Ko ◽  
Chang-Hee Cho ◽  
Hyo-Chan Kwon ◽  
Kwon-Hee Kim

2020 ◽  
Vol 12 (5) ◽  
Author(s):  
Diego Ospina ◽  
Alejandro Ramirez-Serrano

Abstract The limited dexterity that existing hand prostheses provide to users contrasts with the manipulation abilities exhibited by state-of-the-art robot hands. This paper presents an underactuated robot hand with in-hand manipulation capabilities to demonstrate the use of underactuation in the development of effective hand replacements. This paper describes a specific underactuated hand architecture, representative of many existing underactuated hand prototypes. First, the hand is modeled and its ability to manipulate objects of different geometries is analyzed. Second, a manipulation strategy suitable for prosthetic applications is proposed. The strategy enables the hand to manipulate objects in-hand without any a priori information of their geometry or physical properties. Finally, experimental tests conducted to validate the theoretical results are presented.


2013 ◽  
Vol 344 ◽  
pp. 149-152
Author(s):  
Qi Li ◽  
Wen Zeng Zhang

In tradition, one underactuated robotic finger with two or three joints always utilizes only one actuator for self-adaptive grasp, which results in quite weak grasping force because there is only one motor and the motor is so small in size so that it can be embedded into the phalange of the robot finger or the palm of the robot hand. Aiming to overcome the weakness, this paper proposed a novel robotic finger with redundant driving, called RD finger, which can produce sufficient grasping force through increasing a redundant motor and keep original characteristic of self-adaptive grasp. A special single direction transmission mechanism is designed in the finger to make two motors seem like one motor and prevent interference between the first motor and the second motor. The grasping process of the RD finger is close to traditional underactuated finger but there is up to double grasping force. One kind of the RD finger is designed in detail with coupling and self-adaptive grasping mode, which is composed of two motors, bevel gears, a pulley-belt transmission, a single direction transmission and a spring. In addition, the RD finger is compact, easy to control, low in energy consumption, is able to provide wide range of grasping force, and is therefore suitable for humanoid hands.


2015 ◽  
Vol 2015 (0) ◽  
pp. _1P2-N05_1-_1P2-N05_2
Author(s):  
Kengo YAMAGUCHI ◽  
Yasuhisa HIRATA ◽  
Kazuhiro KOSUGE

2021 ◽  
pp. 027836492110489
Author(s):  
Qiujie Lu ◽  
Nicholas Baron ◽  
Angus B. Clark ◽  
Nicolas Rojas

We introduce a reconfigurable underactuated robot hand able to perform systematic prehensile in-hand manipulations regardless of object size or shape. The hand utilizes a two-degree-of-freedom five-bar linkage as the palm of the gripper, with three three-phalanx underactuated fingers, jointly controlled by a single actuator, connected to the mobile revolute joints of the palm. Three actuators are used in the robot hand system in total, one for controlling the force exerted on objects by the fingers through an underactuated tendon system, and two for changing the configuration of the palm and, thus, the positioning of the fingers. This novel layout allows decoupling grasping and manipulation, facilitating the planning and execution of in-hand manipulation operations. The reconfigurable palm provides the hand with a large grasping versatility, and allows easy computation of a map between task space and joint space for manipulation based on distance-based linkage kinematics. The motion of objects of different sizes and shapes from one pose to another is then straightforward and systematic, provided the objects are kept grasped. This is guaranteed independently and passively by the underactuated fingers using a custom tendon routing method, which allows no tendon length variation when the relative finger base positions change with palm reconfigurations. We analyze the theoretical grasping workspace and grasping and manipulation capability of the hand, present algorithms for computing the manipulation map and in-hand manipulation planning, and evaluate all these experimentally. Numerical and empirical results of several manipulation trajectories with objects of different size and shape clearly demonstrate the viability of the proposed concept.


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