Comment by siekmanj
5 hours ago
I could not disagree more with the claim about no improvement in robotic actuators.
The torque density and price of actuators has fallen dramatically since Ben Katz's MIT work on mini cheetah. The actuators on the Unitree G1 based on that work are powerful for their size and near quasi-direct-drive. The motors on the BD E-Atlas are completely passively cooled and appear to have really good torque density. Actuators have never been improving faster than they are now.
G1 is a small robot designed for agility, and can't do much real work. That's why it uses lower reduction actuators with low sustained torques, and it'll overheat easily in continuous work. Many of the larger robots (Optimus, Figure, BD Atlas) use higher reduction actuators with strain waves or planetary roller screws. They're designed for higher sustained torques, but are also less agile and less safe for humans to be around. They're also quite heavy (BD Atlas is 90kg), and still can't match human performance.