4 ms·

that is really, really cool. Leveraging spring-like "tendons" to do the leg lifting and resulting in 1/4 the power usage of "normal" robot legs modeled after hu

• Animats 5y ago
  That's been done before. It's just new for Pratt, who previously used series elastic actuators.[1] Those don't do energy recovery; they fake it using a jackscrew and a stiff spring. Running humans have about 70% elastic energy recovery. Cheetahs have around 90%. What you want in a leg muscle is a spring whose spring constant, damping constant, and neutral point you can control. That can be done pneumatically (you need compressed air), hydraulically (you need hydraulic accumulators), mechanically (two springs operated by separate actuators), or electrically (a fast back-driveable motor drive that generates power during compression). All those options have been tried. There's no really good way to make a muscle-like actuator with power to weight ratios comparable to biology. Systems with a fixed spring work, but under a narrower range of conditions. [1] http://www.ai.mit.edu/projects/leglab/robots/Spring_Flamingo/misc_info/faq.html http://www.ai.mit.edu/projects/leglab/robots/Spring_Flamingo...
  • garbagetime 5y ago
    Hello, do you have a source for running humans elastic energy recovery being 70%?