Nonaped

The first stage of this project has been recently accomplished. It included constructing a pneumatic 12-d.o.f. non-articulated robot - Nonaped, and evolving open-loop dynamic locomotion patterns for this robot in hardware.

Three sections of the physical robot are actuated relative to one another with 12 pneumatic pistons, connected to the sections with ball-and-socket joints so that the robot’s kinematics correspond to two consecutively connected Stewart platforms. This structure allows the robot 12 non-articulated internal degrees of freedom. Nine legs are rigidly connected to the section frames. With respect to the world, the robot has three longitudinal and one transversal planes of symmetry and can achieve static mechanical equilibrium while resting on any of its five sides.

Robot is designed to have autonomous power sources - high pressure canister and rechargeable Li-Ion batteries, however, to avoid long-term parameter drift and recharging, during the physical evolutionary experiments, external power supplies were used. For gait fitness estimation, external camera was used mounted above the experimental bay. Forward displacement of the robot's front upper foot reported by camera for each evaluated gait was recorded and used as gait fitness. Measures were taken to avoid the robot configuration influence upon fitness measurements.

Two hardware evolutionary runs were conducted; as a result, several dynamic locomotion patterns evolved. Future work includes evolving sensor-based controllers and implementing algorithms reducing the number of hardware tests required for physical evolution.

Publication: Evolving Dynamic Gaits on a Physical Robot (pdf) 1.69 MB

This project is supported in part by a Microsoft Research University Relations grant for Embedded Systems.

Videos of autonomous operation are available in hi (19.6 Mb) and low (5.16 Mb) resolution.