Our friends at IEEE Automaton have the scoop on a pair of high-powered robot legs that can maintain their balance even when hit with unexpected forces.
When knocked off balance, the robot calculates 170 possible foot positions and picks the most stable solution in just 1 millisecond. But knowing where to plant your feet is only half the battle; the actuators in each of the legs’ joints have to have enough speed and power to take advantage of the step planner before the robot falls. Conventional electric motors can’t provide enough power for the job, but this robot is special.
Junichi Urata and his colleagues at the University of Tokyo’s JSK Lab (led by Prof. Masayuki Inaba) have modified a HRP-3L (one of Kawada Industries‘ bipedal research platforms) with some help from Keio University and the National Institute of Advanced Industrial Science and Technology (AIST). Thanks to a liquid-cooled high-voltage capacitor system the upgraded robot (given the lab’s initials as a suffix) is able to move faster and more powerfully than the standard model.
The capacitor-powered Maxon 200-watt brushless motors (modified to be liquid-cooled) produce instantaneous speeds of over 1000 degrees per second and 350 Nm of torque on the robot’s knee joints. It’s enough to move the legs into position before it falls. All that extra power means the 53 kg (117 lb) robot can even jump 44 cm (17 inches) off the ground, which is much higher than Honda’s All-new ASIMO (which weighs less). If the system doesn’t easily overheat or run into any other problems, it could be the next big thing for robots driven by electric motors. The newly developed motor controller is also being implemented in JSK’s resident musculoskeletal robot Kojiro.
Urata first unveiled the project late last year, and says he plans on adding arms, manipulators, and sensors to the HRP3L-JSK to compete in DARPA’s new robotics challenge. The lab has a longstanding history of developing full-size humanoid robots (which we intend to cover over time), so it’s only natural they would want in on this major milestone. It will be up against Boston Dynamics’ PETMAN, which uses hydraulics to achieve its brand of agility.