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Soft robot serial chain manipulators with the capability for growth, stiffness control, and discrete joints have the potential to approach the dexterity of traditional robot arms, while improving safety, lowering cost, and providing an increased workspace, with potential application in home environments. This paper presents an approach for design optimization of such robots to reach specified targets while minimizing the number of discrete joints and thus construction and actuation costs. We define a maximum number of allowable joints, as well as hardware constraints imposed by the materials and actuation available for soft growing robots, and we formulate and solve an optimization problem to output a planar robot design, i.e., the total number of potential joints and their locations along the robot body, which reaches all the desired targets, avoids known obstacles, and maximizes the workspace. We demonstrate a process to rapidly construct the resulting soft growing robot design. Finally, we use our algorithm to evaluate the ability of this design to reach new targets and demonstrate the algorithm's utility as a design tool to explore robot capabilities given various constraints and objectives.
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Design Space Enumerations for Pneumatically Actuated Soft Continuum Manipulators
Abstract Pneumatically actuated soft continuum manipulators (SCMs) are constructed by combining several extending or contracting fiber reinforced elastomeric enclosure (FREE) actuators in series, parallel and a combination thereof. While it is well known that architectures with serial combinations of FREEs yield large workspace and dexterity, they suffer from design and control complexity, increased number of valves and inertia. Recent advances in exploring the FREE design space has demonstrated using parallel combinations of dissimilar FREEs (bending and rotating) to improve workspace and dexterity. This paper presents a comprehensive investigation of SCM design architectures by enumerating possibilities of serial and parallel combinations of similar and dissimilar FREEs. A novel dexterity metric is proposed to enable objective comparison of different SCM designs based on shape similarity and end-effector tangent. Given a fixed resource of control inputs (actuator and valve inputs), the paper systematically selects the best architecture of the SCM (serial, parallel, similar or dissimilar FREE) that maximizes dexterity and workspace. It is seen that optimal designs are heavily dependent on the context of the application, which may change how these manipulators are deployed. The paper presents two practical design applications that demonstrate the usefulness of the enumeration framework. While in general, serial design combinations using symmetric bending actuators result in larger workspace and dexterity, some architectures with asymmetric combinations of FREEs may see similar levels of dexterity and workspace.
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- Award ID(s):
- 1954556
- PAR ID:
- 10496363
- Publisher / Repository:
- American Society of Mechanical Engineers
- Date Published:
- ISBN:
- 978-0-7918-8736-3
- Format(s):
- Medium: X
- Location:
- Boston, Massachusetts, USA
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Conference Paper:
- https://doi.org/10.1115/DETC2023-116930
