Researchers at Oregon State University (OSU; Corvallis, USA) are working toward improving a robotic locomotion method that uses far less energy than current configurations, in an attempt to closer approximate the abilities of animals. Humans and other animals use limited energy, and can move easily over uneven terrain, using a complicated balancing act of muscles and tendons to flex opposing pairs of muscles, thus changing the dynamic properties of their limbs. Existing robots, on the other hand, can walk and run, but tend to be as rigid as possible when achieving a basic gait, as well as using large amounts of energy in the process.

This is because a robot finds it difficult to perform both tasks at the same time; the more it is able to do one of these tasks, the less able it is to do the other. As part of their investigations, the researchers decided to examine ostriches, making direct comparisons to robotic behavior. Ostriches, like other animals, have a great ability to respond to unexpected disturbances while running, which could provide insights into the needed robotic equivalent, a combination of spring-mass models with force control actuators. The results of the research were presented at the IEEE Conference on Robotics and Automation, held during May 2010 in Anchorage (AL, USA).

"If robotic locomotion is ever to achieve some of what we want, it will have to use less energy. There are machines that can walk with no active controls at all, using barely any energy, but they fall if they run into the smallest bump,” said Jonathan Hurst, Ph.D., an assistant professor of robotics and mechanical design at the dynamic robotics laboratory at OSU. "We need to use as much of that passive ability as possible and only use motors or active controls if it's really necessary, so we can save energy in the process.”

"Researchers have been working toward robot locomotion for a long time based mostly on experience and intuition,” added Dr. Hurst. "What we've done is taken a step back to analyze the fundamental dynamics of the mechanical system, what behavior is really possible for a given robotic system. This is an important advance and gives us a new foundation to tell what actually will and won't work before we even try to build it.”

By achieving an optimal approach with robotic mechanisms, the researchers are moving closer to robots that could take on dangerous missions in the military, create prosthetic limbs for humans that work much better, or even help some people who use wheelchairs regain "walking" abilities.

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Oregon State University