Despite the popular notion, propagated by Hollywood and the media, that humanity should fear its extermination at the hands of evil humanoid robots with superhuman strength, the reality is that the electric motors used to power most robots aren't very powerful at all. Famous examples like Honda's ASIMO are only capable of lifting a few kilograms, and most other adult-size robots could be described as having one-tenth the strength of the average person. So much for Terminator and the rise of the machines!
But now a Japanese startup, SCHAFT Inc., has announced a breakthrough in motor technology that may bypass the limitations of existing systems. The company, a spin-off of the University of Tokyo's Jouhou System Kougaku (JSK) Laboratory, has developed—and patented—a new kind of actuator that may make robotic muscles much stronger. Gulp.
The Urata Leg replaced the standard servos with high output capacitor-powered, water-cooled motor systems. These, along with advanced bipedal control algorithms, allowed the robot to maintain its balance when kicked and shoved. Suddenly, the compact size of the electric motors—a necessity in humanoid robots—no longer meant sacrificing strength. Not long after, the JSK researchers decided to spin off SCHAFT to market the technology. At the heart of their system is a high-voltage and high-current liquid-cooled motor driver that gets its power from a capacitor. The capacitor can supply lots of current very fast and reliably, something that batteries are not good at. This in turn allows the electric motor to deliver high speed and high torque to the arm, something that is hard to do with conventional motors. [The motor, the driver, and the arm are pictured above, from left to right.]