Energy-based approach to develop soft robots
Abstract
Soft robotic systems offer advantages against rigid robot systems in applications that
involve physical robot-human interactions, unstructured or extreme environments, and
manipulating delicate objects. Soft robots can offer inherently safe operation and adapt
to unknown geometry of the environment or object. The current soft robot development
approach is an empirical approach starting from a type of soft actuation technology,
whereas the development of rigid robots can start from a top-level task in a System Engineering framework. The rigid robot developer can select from well-defined components
to construct the task-orientated system. Soft robots are relatively novel systems compared with rigid robots and do not have well-defined components due to a wide range
of soft actuation technologies. The initial choice of soft actuation technology places
constraints on the system to perform the task. Soft robotic systems are not widely used
despite the advantages compared to rigid robots.
In this thesis, I study an abstraction approach to enable a System Engineering framework
to develop soft robotic systems. My research focus is on an energy-based approach that
encompasses the multi-domain nature of soft robotic systems. The impact on the final
system from the energy transfer characteristics of the initial choice of the soft actuator
has not been fully explored in the literature. I study how energy, and rate of energy
transfer (power), can describe different components of each type of soft actuation and
how the total energy can model the top-level system. This thesis includes (i) a literature
review of soft robots; (ii) an abstraction approach based on bond-graph theory applied
to soft actuation technologies; (iii) a port-Hamiltonian theory to describe the top-level
soft robotic system, and (iv) an experimental application of the approach on a type of
soft actuation technology.
In summary, I explore how energy and rate of energy transfer can provide the abstraction
approach and in time provide the well-defined components necessary for task-orientated
design approaches in a System Engineering framework. In particular, I applied the
approach to soft pneumatic systems for additional insights relevant to the development
of future task-orientated soft robotic systems.