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Comment by causal | Hacker News Reader

I'm always wondering at the safety measures on these things. How much force is in those motors?

This is basically safety-critical stuff but with LLMs. Hallucinating wrong answers in text is bad, hallucinating that your chest is a drawer to pull open is very bad.

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In terms of low-level safety, they can probably back out forces on the robot from current or torque measurement and detect collisions. The challenge comes with faster motions carrying lots of inertia and behavioral safety (e.g. don't pour oil on the stove)

That's actually more of a solved problem. Robot arms that can track the force they're applying and where to avoid injuring humans have been kicking around for 10-15 years. It let them go out of the mega safety cells into the same space as people and even do things like letting the operator pose the robot to teach it positions instead of having to do it in a computer program or with a remote control.

The term I see a lot is co-robotics or corobots. At least that's what Kuka calls them.

That's fine for wheeled robots or robots bolted to the floor but for legged robots, especially bipeds, the hard question is how to prevent them from falling over on things. These don't look heavy enough to be too dangerous for a standing adult but you've still got pets/children to worry about.

You can have dedicated controllers for the motors that limit their max torque.

That's not enough. When a robot link is in motion and hits an object, the change in momentum creates an impulse over the duration of deceleration. The faster the robot moves, the faster it has to decelerate, the higher the instantaneous braking force at the impact point.

Then limit max velocity.

Not a big deal on the battlefield.

I'd say a very big deal when munitions and targeting are involved

Why do you think that?

Battle fields are violent and exhausting, people get the shakes, make mistakes, hurt themselves and each other all the time. Munitions are generally designed to not explode from a bump in the road or getting dropped or squeezed, and targeting systems commonly support automatic tracking or similar, for this specific reason.

The thing in the video moves slower than the sloth in Zootopia. If you die by that robot, you probably deserve it.

Are you saying it cannot move faster than they because of some kind of governor?

A governor, the firmware in the motor controllers, something like that. Certainly not the neural network though.

That is how I would design it. It is common in safety critical PLC systems to have 1 or more separate safety PLCs that try to prevent bad things from happening.

Although in a SIL safety system the dangerous events are identified and extremely thoroughly characterized as part of system design.

There cannot be a safety system of this type for a generalist platform like a humanoid robot. It's possibility space is just too high.

I think the safety governor in this case would have to be a neural network that is at least as complex as the robots network, if not more so.

Which begs the question: what system checks that one for safety?

Limiting max force applied CAN be can be characterized for this robot.

As a sibling comment implies though, there's also danger from it being stupid while unsupervised. For example, I'd be very nervous having it do something autonomously in my kitchen for fear of it burning down my house by accident.

or if you're old, injured, groggy from medication, distracted by something/someone else, blind, deaf or any number of things.

it's easy to take your able body for granted, but reality comes to meet all of us eventually.

From a different robot (Boston Dynamics' new Atlas) - the system moves at a "reasonable" speed. But watch at 1m20s in this video[1]. You can see it bump and then move VERY quickly -- with speed that would certainly damage something, or hurt someone.

[1] https://www.youtube.com/watch?v=F_7IPm7f1vI

Especially if holding a knife or something sharp.

They are designed to penetrate Holtzman shields, surely.

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