Biologically inspired anthropomorphic arm and dextrous robot hand actuated by smart-material-based artificial muscles

Pneumatic artificial muscles (PAMs) are used in robotics applications for their light-weight design and superior static performance. Additional PAM benefits are high specific work, high force density, simple design, and long fatigue life. Previous use of PAMs in robotics research has focused on using “large,” full-scale PAMs as actuators. Large PAMs work well for applications with large working volumes that require high force and torque outputs, such as robotic arms. However, in the case of a compact robotic hand, a large number of degrees of freedom are required. A human hand has 35 muscles, so for similar functionality, a robot hand needs a similar number of actuators that must fit in a small volume. Therefore, using full scale PAMs to actuate a robot hand requires a large volume which for robotics and prosthetics applications is not feasible, and smaller actuators, such as miniature PAMs, must be used. In order to develop a miniature PAM capable of producing the forces and contractions needed in a robotic hand, different braid and bladder material combinations were characterized to determine the load stroke profiles. Through this characterization, miniature PAMs were shown to have comparably high force density with the benefit of reduced actuator volume when compared to full scale PAMs. Testing also showed that braid-bladder interactions have an important effect at this scale, which cannot be modeled sufficiently using existing methods without resorting to a higher-order constitutive relationship. Due to the model inaccuracies and the limited selection of commercially available materials at this scale, custom molded bladders were created. PAMs created with these thin, soft bladders exhibited greatly improved performance.

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Research on Image Vectorization Based on Dual-Thumb Pneumatic Flexible Robot Hand

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.989-994.3181 ◽

2014 ◽

Vol 989-994 ◽

pp. 3181-3184

Author(s):

Shao Song Wan ◽

Jian Cao ◽

Qun Song Zhu ◽

Cong Yan

Keyword(s):

Feature Fusion ◽

Nonlinear Problems ◽

Middle Finger ◽

Artificial Muscles ◽

Robot Hand ◽

Flexible Robot ◽

Inference Mechanism ◽

Flexible Joint ◽

Image Vectorization ◽

Parallel Arrangement

Because the traditional linear vectorization methods have some shortcomings including processing data slowly, being sensitive to noises and being easy to be distorted. Fuzzy rules and its inference mechanism are the assurance of achieving feature fusion. This paper has a design and analysis on the dual thumb pneumatic flexible robot hand base on the active flexible bending joints we have developed. The flexible joint is composed of four elongation artificial muscles with parallel arrangement. The robot hand has five multi-actuated fingers each with three flexible joints. To improve the flexibility and stability of grasp, the other four fingers are orthogonal and symmetrical except the middle finger, which forms the dual thumb oriented grasp model. Furthermore, we study on the position and posture of fingers applying the parameterized homogeneous transformation to the large deformation and nonlinear problems of flexible joint.

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