After having created their own bipedal humanoid from the ground up with the HRP-2P, AIST made significant modifications in 2003 leading to the HRP-2 Promet. The HRP-2P couldn’t walk for more than 30 minutes without the leg’s actuators overheating, resulting in lower torque and in the worse case scenario, a fall. Cooling systems were incorporated in the legs’ actuators to increase endurance, while also reducing the internal heat from around 118°C down to 60°C. Many of the joints were stiffened, improving performance. Specially designed batteries were developed to make the torso even more compact than it was in the HRP-2P, and the frame underwent FEM analysis to determine exactly where the structure needed to be strengthened to dampen mechanical resonance.
The exoskeleton wasn’t ignored either, having been given a more friendly appearance. In fact, it was decided that the outer shell was more important than the movable range of each joint, since the design sometimes obstructed movement (the movement ranges were still good enough for their purposes). It may look familiar if you’ve seen the Japanese anime Patlabor (Yutaka Izubuchi, the mechanical designer on that series was commissioned to design the look of it). This gives the Promet’s head a futuristic sci-fi look, while also making room for the 4 CCD cameras and 8 microphone array. 3 of the cameras are used for stereoscopic imaging while the 4th is used for SLAM (simultaneous localization and mapping) purposes.
The HRP-2 Promet has proven a popular research platform, having been used in a wide variety of humanoid robotics experiments ever since its creation. Sophisticated collision models have been implemented in software that allow scientists to test motion patterns on a virtual model within a simulated or real environment, similar to augmented reality programs. Objects in the laboratory are modeled in the software as well, and tracked using a motion capture set-up with multiple cameras. This allows the robot’s virtual environment to more closely match the real one, all in real-time, which helps the robot avoid obstacles and find important landmarks (like stairs).
Although it does have some autonomy, such as the ability to move towards a goal position in cluttered environment, it can also be teleoperated by a human. Researchers developed an “Intelligent Joystick” control system that allows a person to control the robot using a simple game controller. The robot retains its lower-level autonomy in deciding the best foot placement to achieve the desired position. Using this system, it is possible to command the robot to walk forward, while the robot automatically adjusts its footing to compensate for obstacles that might be in the way.
Some of the other work done with the HRP-2 Promet includes: visual-guided grasping while moving, such as grabbing a ball while walking towards it; walking with each footstep placed directly in front of the last (e.g. along a narrow path or beam); lying down and getting up under its own power; crawling; 2.5km/h walk; and many more.
- AIST (official site JP/EN)
- AIST Humanoid Robotics Group (JP/EN)
- HRP-2 Promet movies @ AIST (JP)
- Kawada Industries: HRP-2 Promet (JP/EN)
- HRP-2 Promet @ Impress Robot Watch (JP) (2) (3)
- HRP-2 Promet papercraft
- HRP-2 Promet appears on postage stamp (JP)
AIST | Impress Robot Watch