zlacker

>>ummonk+(OP)
Servo based systems are both incredibly power and incredibly fast. So fast that if you've never seen a servo based arm move at top speed and come to that top speed at top acceleration you'd be forgiven to think that I'm exaggerating.

Depending on the application there are different layers of safety surrounding these systems, including perimeter guards, optical barriers, limit switches, resistance based detection and so on. But when a system is broken someone has to go in and fix it, and you tend to do that with the robot powered up, some of the safety systems disabled so you can actually work on it and if you're really unlucky a motor will end up shorted against a + or - rail while you're within reach. This is obviously dangerous, and it is more dangerous because broken equipment can't be trusted to behave in a predictable way.

They won't stop. Not until whatever is obstructing has moved or the motor has burned out (or someone has the presence of mind to hit the e-stop). I've seen a 3" thick mount that must have weighed well over a ton sheared clear of its bolts (which themselves were an inch thick) by a malfunctioning servo on a very large lathe under construction (think 8 foot chuck for crane cable idler wheels). Do not fuck with servo systems unless you are 100% sure they are safe to approach or you may well end up dead or gravely injured.

>>jacque+65
> and you tend to do that with the robot powered up

I thought OSHA and friends didn't allow this. Lockout/tagout is standard.

> some of the safety systems disabled

There's a simple one which ought to be more common: current limiter on the drive power supply. Makes everything slow and weak.

>>crotch+m8
There's a catch 22 when repairing machinery, you have to see it in action to determine what is going wrong, and sometimes this means getting up close with it during operation. I've seen many techs/mechanics bypass guards and not use lockouts when diagnosing machinery problems. And of course everyone is "ok" with it because they are supposed to be experts and know what they are doing.

>>Magi60+1b
> There's a catch 22 when repairing machinery, you have to see it in action to determine what is going wrong, and sometimes this means getting up close with it during operation.

This is 2023 and we are well into the age of ubiquitous, cheap, small cameras.

Place cameras such that paths can be observed at a safe distance and diagnose problems in powered machinery without placing a person in harm’s way.

>>mister+Df
Between depth of focus, various obstructions, details that are too small to notice until they bite you, multiple angles, very large spans of travel etc I don't think that's feasible. It's one of those 'why don't they' statements where an outsider thinks they have an obvious solution to something when the experts in the field are anything but stupid.

What does work is to disconnect the motors while keeping the rest of the electronics powered up but not all industrial robots have such a facility. The e-stop will disconnect everything and that stops you from doing things like firmware upgrades. And when things are broken it gets even more complicated and unpredictable.

Servicing machinery like this is difficult, sometimes dangerous (but not even the most dangerous, for that you have to go visit a steel mill) but not impossible. The biggest danger really is familiarity with the machines to the point that you stop to respect them, that's when you are really in danger. Personally you can't pay me to go near one when it isn't locked out, I'd much rather field strip it and test the components one by one than taking a risk but a service tech might be promised a bonus if they can get it working again quickly and that might cause them to work in less safe ways.

I've seen people do incredibly stupid stuff with machinery and I've also seen the results in terms of fingers and sometimes eyes or whole limbs lost as evidence of prior fuck-ups. And some of those people still took risks afterwards.

Walk into any metal machining shop and just watch, it won't be an hour before you see someone do something that they shouldn't be doing. And in almost all cases it will end up without anything being damaged or someone being injured. One more step on the 'normalization of deviation' track. It always ends the same.