[gene-h]

If it really is using all electric actuators that's pretty big. This would be one of the first of Boston Dynamics' all electric robots.

What exactly does using electric actuators over hydraulics buy us? Less noise, greater efficiency, and reliability. Reliability is very important for both house hold and industrial robots. We typically measure reliability in terms of Mean Time Between Failures, aka, how long it typically last before breaking. For industrial robots this is important as the higher the reliability is the more money it makes. Industrial robots tend to have MTBFs of 100,000 hours or about 10 years.

Reliability is also important for household robots too, a big expensive robot that breaks down all the time appeals to few people.

[Animats]

The previous Spot robot was also all-electric. Hydraulic power was needed for the bigger machines. (Also, Raibert liked designing hydraulic systems; he has a patent on the valve/actuator combo used in BigDog.) Cube/square law - mass increases with the cube of the size. This is why insects have tiny leg cross sections in comparison to their length.

Battery life will be a problem, but it's clearly agile enough to plug itself in for a recharge.

[sharemywin]

you could also have some kind of stand by packs waiting.

[jonnycowboy]

Reliability is not an issue for industrial hydraulics (they rarely break down) however they do require a lot of maintenance, are filled with hot (dirty) hydraulic fluid and are noisy (pumps). Electric solves all those issues.