2 ms·

I stand corrected! Thank you. I'm still mostly convinced that harvesting the energy and re-using it ala elastic tendons is a decently good idea. But probably f

• Animats 3y ago
  It's mostly for distance running. Humans get about 70% of energy back in running. Cheetahs, about 90%. Variable compliance muscles are desirable, but hard to do. A pneumatic cylinder with adjustable pressure on both sides will do it, and Festo builds a lot of that for industrial automation. Two opposed springs pulled on by two positional actuators will do it, but that's kind of bulky. There's a hack called a "series elastic actuator", which is a rigid positional actuator with a stiff spring on the end. When it gets some pushback, the spring compresses, and the motor frantically tries to move the positional actuator before the spring bottoms out. This allows you to simulate a spring with off the shelf screw jacks. Those new direct-drive motors are a good solution. Direct-drive pancake motors have been around for a while, but they used to be about a foot across. Now they're smaller. Probably a spinoff of drone motor technology.
• Corrado 3y ago
  Actually, that's a pretty good idea. Regenerative motion. Sort of like regenerative braking in an EV, they could capture some electricity with each step to help reduce the energy requirements.