To improve the operation of robots researchers have designed a way to replicate the muscle motion of the human eye to control camera systems.
This new muscle-like action could help make robotic tools safer and more effective for MRI-guided surgery and robotic rehabilitation.
Key to the new control system is a piezoelectric cellular actuator that uses a novel biologically inspired technology that will allow a robot eye to move more like a real eye.
This will be useful for research studies on human eye movement as well as making video feeds from robots more intuitive.
Ph.D. candidate Joshua Schultz is conducting the research under the direction of assistant professor Jun Ueda, both from the George W. Woodruff School of Mechanical Engineering at the Georgia Institute of Technology.
"For a robot to be truly bio-inspired, it should possess actuation, or motion generators, with properties in common with the musculature of biological organisms," said Schultz.
"The actuators developed in our lab embody many properties in common with biological muscle, especially a cellular structure. Essentially, in the human eye muscles are controlled by neural impulses. Eventually, the actuators we are developing will be used to capture the kinematics and performance of the human eye," he explained.
Ueda, who leads the Georgia Tech Bio-Robotics and Human Modeling Laboratory in the School of Mechanical Engineering, said this novel technology will lay the groundwork for investigating research questions in systems that possess a large number of active units operating together. The application ranges from industrial robots, medical and rehabilitation robots to intelligent assistive robots.
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. 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," said Ueda.
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.
Future research by his team will continue to focus on the development of a design framework for highly integrated robotic systems. This ranges from industrial robots to medical and rehabilitation robots to intelligent assistive robots.
Details of the research were presented June 25, 2012, at the IEEE International Conference on Biomedical Robotics and Biomechatronics in Rome, Italy.