"Robustness against uncertainty of model and environment is crucial for robots physically interacting with humans and environments," said Ueda. "Successful integration relies on the coordinated design of control, structure, actuators and sensors by considering the dynamic interaction among them."
Piezoelectric materials expand or contract when electricity is applied to them, providing a way to transform input signals into motion. This principle is the basis for piezoelectric actuators that have been used in numerous applications, but use in robotics applications has been limited due to piezoelectric ceramic's minuscule displacement.
The cellular actuator concept developed by the research team was inspired by biological muscle structure that connects many small actuator units in series or in parallel.
The Georgia Tech team has developed a lightweight, high speed approach that includes a single-degree of freedom camera positioner that can be used to illustrate and understand the performance and control of biologically inspired actuator technology. This new technology uses less energy than traditional camera positioning mechanisms and is compliant for more flexibility.
"Each muscle-like actuator has a piezoelectric material and a nested hierarchical set of strain amplifying mechanisms," said Ueda. "We are presenting a mathematical concept that can be used to predict the performance as well as select the required geometry of nested structures. We use the design of the camera positioning mechanism's actuators to demonstrate the concepts."
The scientists' research shows mechanisms that can scale up the displacement of piezoelectric stacks to the range of the ocular positioning system. In the past, the piezoelectric stacks available for this purpose have been too small.
"Our research shows a two-port network model that describes compli
|Contact: John Toon|
Georgia Institute of Technology Research News