Osaka University’s Hosoda Lab is presenting Pneuborn-7II and Pneuborn-13, two musculoskeletal infant robots, at ICRA 2011. Their names play on the pneumatic muscles used as actuators throughout their bodies, which can contract approximately 25% when compressed air is supplied. This type of actuator uses soft flexible materials, allowing the robots to interact with their environment, sometimes for several hours at a time, without risking mechanical damage or overheating.
Measuring the size of a 7 month old infant, Pneuborn-7II was built to study the relationship between motor development and embodiment. It is 80cm (31″) tall, weighs 5.4kg (11.9 lbs), and has 26 degrees of freedom actuated by 19 pneumatic muscles. Notably, the robot’s spine has three pitch and yaw joints that allow it to rotate, flex, and extend. It is fully autonomous, containing a micro controller, battery, air valves, and an air source (compressed C02 cartridge bottle). During long experiments, air can be provided through an external compressor.
The researchers implemented a learning algorithm based on central pattern generators with an optimization method, which was able to generate successful crawling forward motions. They were able to accomplish this despite the robot’s lack of sensors or sophisticated artificial intelligence. Central pattern generators (or CPGs for short) are a type of neural network that are often used in robotics to create rhythmic motions that are especially useful for simple locomotion such as crawling or rolling over.
Pneuborn-13 models a 13 month old infant, and was developed to study the effect the musculoskeletal structure itself has on the emergence of bipedal walking. As a result, its 18 pneumatic muscles are concentrated in its ankle, knee, and hip joints. It measures 75cm (29.5″) tall, weighs 3.9kg (8.5 lbs), and has 21 degrees of freedom. Like Pneuborn-7II it is wholly autonomous, and has a similar skeletal structure, but it doesn’t have an actuated spinal column. The robot is able to hold a standing posture and can make stepping motions.
Hosoda Lab has not yet published videos of these robots on their website, but we expect that videos will be made public soon. Photos and project details from “Pneumatic Musculoskeletal Infant Robots” by Kenichi Narioka, Ryuma Niiyama, Yoichiro Ishii, and Koh Hosoda. Osaka University is known for its cognitive developmental robotics (see also CB², Noby, Affetto, and M3-Neony), and Ryuma Niiyama has also worked on Tokyo University’s famous musculoskeletal Athlete Robot.