Digital Theses Archive


Tesi etd-01302018-125734

Type of thesis
Shah, Syed Taimoor Hassan
“Bio-Inspired designs for multi-functionality, based on braided structures”
Scientific disciplinary sector
INGEGNERIA - Biorobotics (Marie Curie ITN fellows)
relatore Prof. DARIO, PAOLO
  • Adaptive morphology
  • locomotion
  • manipulation
  • soft actuation
  • Soft robotics
  • stiffness modulation
Exam session start date
Soft robotics has the potential for producing future generations of robotic systems capable of sharing the workspace/workload with humans in an un-structured environment, a capability lacking in today’s industrial systems. The domain mimic’s nature in shape, function and process for producing compliant systems capable of highly dexterous “natural” motions and stiffness modulation. Such properties insures safe interaction and load variation. <br>This research focuses on the braid structure as a design solutions capable of providing the above mentioned capabilities, for applications in soft actuation, manipulation and locomotion. A novel bi-directional pneumatic muscle is developed, which is based on the working principle of Mc-Kibben type pneumatic muscle but is able to produce bi-directional forces and motion. Finite element simulations were used as a design tool for the development of the physical prototype, with emphases on the deformation of the braided structure, which plays an important role in the working of the technology. A case study is presented where the muscle is used as the primary driver for a bi-directional variable stiffness joint. An &#34;octopus-like&#34; robotic arm based on soft mechatronic technologies is also developed. The design takes its inspiration from nature, more specifically from muscular hydrostats and has the ability to expand, contract and bend in 3D-space with varying stiffness. The system employs a hybrid actuation scheme. The concept of the design is based on helically braided structures. The braids were previously analysed for the bi-directional pneumatic braided muscle actuator. These crossed-linked helical array structures, ideally composed of non-extensible yet flexible fibers, exhibit some special modes of structural deformation. When extended or contracted axially, the structure is capable of considerable accommodation of strain since the angle between the fibers and the longitudinal axis of the structure can change. Moreover the structure can bend smoothly without kinking under external forces. For the manipulator design the braid structure was scaled up and was first analysed using finite element analysis, the results were validated through mechanical characterization of physical prototypes. Furthermore a similar braided structure is employed to develop an In-pipe robot able to produce peristaltic locomotion. The soft structure enables it to adapt to internal pipe diameter changes as well as bends. Furthermore it is capable of manoeuvring horizontal and vertical pipes.