Optimal Control of Actuator Arrays with Electric and Thermofluidic Inputs

University Of Utah, Salt Lake City UT

Investigators

Abstract

The objective of this research award is to characterize the performance of an array of Shape Memory Alloy (SMA) actuators with multiple energy-domain inputs. By embedding SMA "muscle" wires in a biologically inspired "vascular" system, they can be actuated with combinations of electric and thermofluidic inputs. Electric activation is faster, while thermofluidic activation offers higher energy-storage capacity. The research approach is to first model the dynamics of a single "wet" SMA actuator to characterize speed and energy use as a function of the inputs and design parameters. The second task is to characterize the ability of optimal control strategies to balance speed and energy consumption of arrays of these actuators. The "muscles" will be actuated in a binary fashion (fully contracted/extended) and bundled together in series/parallel to achieve discrete displacements/forces. A scalable Network Array Architecture of electric and thermofluidic controls will activate the muscles. Graph Theory will be used to develop intelligent control algorithms to operate the networked actuator arrays. This research will characterize the performance of these unique actuator systems using methods that can be adapted to other "wet actuators" such as Fuel-Powered SMAs and ElectroActive Polymers. Wet Actuators are anticipated to advance the capabilities of a variety of robotic systems such as prosthetics, exoskeletons, haptic devices and biomimicing robots. This work also aims to expand bioinspired robotics in a direction where the bioinspiration is anatomical and physiological in nature rather than in form and function. This research will be integrated into graduate, undergraduate and preparatory education by 1) enhancing graduate level courses to incorporate interdisciplinary engineering, 2) supervising capstone design projects focused on demonstrating wearable robotic applications, and 3) developing a novel educational Wet SMA Robot Kit that will be used in conjunction with existing K-12 outreach programs sponsored by the College of Engineering Office of Outreach and Diversity.