Engineering news
By changing the flexibility of its couplings, the robot can be made to turn without the need for complex computational control systems. The work could assist development of rescue robots that traverse uneven terrain, said the researchers from the Department of Mechanical Science and Bioengineering.
Most animals have evolved a robust locomotion system using legs that provide them with a high degree of mobility over a wide range of environments. Engineers who have attempted to replicate this approach have often found that legged robots are surprisingly fragile, however. The breakdown of even one leg due to repeated stress can severely limit the ability of robots to function.
Controlling a large number of joints so the robot can transverse complex environments also requires a lot of computer power. Improving on that approach could be extremely useful for building autonomous or semi-autonomous robots that could act as exploration or rescue vehicles.
The new biomimetic ‘myriapod’ robot takes advantage of a natural instability that can convert straight walking into curved motion. Consisting of six segments, with two legs connected to each segment and flexible joints, the robot has adjustable screws that can modify the flexibility of couplings using motors during walking.
The researchers showed that increasing the flexibility of the joints led to a situation called a ‘pitchfork bifurcation’, in which straight walking becomes unstable. Instead, the robot transitions to walking in a curved pattern, either to the right or to the left.
Normally, engineers would try to avoid creating instabilities, but using them in a controlled way can enable efficient manoeuvrability.
“We were inspired by the ability of certain extremely agile insects that allows them to control the dynamic instability in their own motion to induce quick movement changes,” said Shinya Aoi, an author of a new study on the robot.
Because the approach does not directly steer the movement of the body axis, but rather controls the flexibility, it can greatly reduce both the computational complexity as well as the energy requirements.
The team tested the robot’s ability to reach specific locations and found that it could navigate by taking curved paths toward targets.
“We can foresee applications in a wide variety of scenarios, such as search and rescue, working in hazardous environments or exploration on other planets,” said Mau Adachi, another study author.
Future versions could include additional segments and control mechanisms.
The study was published in Soft Robotics.
Want the best engineering stories delivered straight to your inbox? The Professional Engineering newsletter gives you vital updates on the most cutting-edge engineering and exciting new job opportunities. To sign up, click here.
Content published by Professional Engineering does not necessarily represent the views of the Institution of Mechanical Engineers.