# Would the strength and speed of a robot skeleton be a danger to its wearer?

Expanding upon the title, I am querying the use of robotic skeletons to augment human strength and speed. If such a robot had the capacity for example to bear weight 5 times heavier than the wearer and move its robotic limbs twice as fast as the wearer, is there not a danger because such powerful and sharp movements could break their bones and seriously injure them because it moves beyond their human capabilities?

The robots means of producing movement I would think is important here but unsure how so. The nature of passive or actively powered movement and when each mode is used will also determine performance of the exoskeleton. I am not well versed in this area so will appreciate any feedback.

• Well of course any human part that may be put under pressure by the exoskeleton should also be fortified. That is, the exoskeleton should be able to take all the pressure. In that case, then no it won't hurt the human. Or did I misunderstand your question? – Shahbaz Apr 29 '13 at 15:50
• Strength is only secondary, acceleration is more interesting, and the negative acceleration is it. Image hitting a wall or the floor with 30 m/s. – ott-- May 3 '13 at 14:50

Yes, an exoskeleton would definitely be a danger to its wearer, if it were not properly controlled.

In science fiction this problem is solved by the system requiring the human wearer to bear some of the weight themselves. Thus the 5x multiplier would still require the wearer of the exoskeleton to exert their full effort to lift the 1/5 of the weight themselves.

Similarly, the user would only be able to move more quickly because it is less effort to move a light weight than a heavy one, so in this case the exoskeleton is reducing the apparent weight to allow it to be moved more quickly.

Any control system which allowed the wearer of the exoskeleton to be injured through normal use of the exoskeleton would not be considered safe and would require the control system to undergo another risk assessment and the problems with the control system to be removed.

Incidentally, this is no different to a robot being strong enough to damage itself. I once worked on a robot which was more than capable of ripping straight through the protective cage which surrounded it.

The cage was not there to protect humans outside of the cage from an out of control robot, as this was considered a very low risk. It was primarily to prevent humans getting into the working envelope of a properly controlled robot, because out of control humans were considered a much greater risk (mostly to themselves *8').

• What is that *8'? – Shahbaz Apr 30 '13 at 8:28
• It's a smiley, just one with hair *, wearing glasses (8 rather than :), with a nose ' and looking slightly from the side (' rather than -). Because the smiley is related to the parenthetical comment I reuse the ) for the end of the smiley. *8') – Mark Booth Apr 30 '13 at 8:31
• Haha, I do that myself (all the time :) but this time for some reason I had a parse error. – Shahbaz Apr 30 '13 at 8:36