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#76
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Re: Safety Issue: Robots Moving in Pits
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It must be recognized that the negative outcome is not the desired outcome when testing a mechanism and that it is only one of many possible outcomes, most of them positive. It must also be recognized that the negative outcome of testing a mechanism is often unforeseen. Totally denying the opportunity for that negative outcome to occur means that the team developing the mechanism does not have the chance to know about the negative outcome and so they will not find a way to mitigate it. Thus the hazard still exists. It has just been shifted to a different time and place. Quote:
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#77
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Re: Safety Issue: Robots Moving in Pits
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#78
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Re: Safety Issue: Robots Moving in Pits
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And if we are really talking about preparing kids for the "real world" industries, how many companies ignore significant safety hazards cause new rules would make "the manuals too long." I am sure there are lots of teams who don't read the manuals as they are written now and that would be unlikely to change even if we did shorten them. TL;DR is a real thing after all. That is why (like other game and safety rules) it has be regularly discussed and enforced until it becomes as natural as wearing safety glasses. |
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#79
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Re: Safety Issue: Robots Moving in Pits
I don't get this discussion.
Just don't let the wheels touch anything. Don't unplug your electrical components, don't stare at/rely on your e-stop, just get some 2x4s and put them under it. If you don't want it to drive away don't let it! |
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#80
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Re: Safety Issue: Robots Moving in Pits
I just want to reiterate that it's impossible to properly test any floor pickup mechanism without the robot on the floor. There are times when wheels have to be on the ground. A number of good solutions have been proposed, including simply pulling breakers which is really even easier than propping a robot up.
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#81
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Re: Safety Issue: Robots Moving in Pits
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2. Depending on your design geeting to a breaker may not be ideal for repeted tests. It also adds another chance for error. If someome put it back in the wrong spot or worse forgot to turn of the robot first, for example. |
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#82
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Re: Safety Issue: Robots Moving in Pits
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Getting the relative height of the 2x4s vs the platform correct is also tricky (2x4s must be taller than wheel ground clearance, platform has to be difference between two) Quote:
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#83
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Re: Safety Issue: Robots Moving in Pits
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The idea of relying on code is fine but it doesn't remove the human error from the problem. The issue of a runaway robot would probably a software problem anyway. It also doesn't account for an electrical failure causing the problem. The breaker is the next best in my opinion but it's to easy to pull out or replace the wrong one and is sill subject to a more catastrophic problem, albeit less likely. Also if a team can't think up a simple plywood and 2x4 platform how did you build a robot with a pickup system? |
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#84
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Re: Safety Issue: Robots Moving in Pits
I think it's not so much a matter of not being able to make a simple platform, but rather it being much more time efficient to simply pull out the breakers. I agree that it would be highly unfortunate if one were to plug the breakers back into the wrong spot, but this can be easily managed by a bit of attentiveness and clear labeling of the ports on the PD board.
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#85
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Re: Safety Issue: Robots Moving in Pits
Pull your Andersons for each drive motor.
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#86
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Re: Safety Issue: Robots Moving in Pits
That only works if you use a reusable connector between motors and the PDB. We (4080) do have Andersons between motors and Tallons so we can follow that advice. Some teams like to solder however.
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#87
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Re: Safety Issue: Robots Moving in Pits
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Programming & e-stop scenario: Team 9999 has just arrived to their regional on Saturday morning and is eager to test their auto which closes a gripper around a can and drives backwards with it. They orient the front of the robot facing the inside of the pit with can in place. The operator places the laptop on a chair behind the robot which is facing the isles. In the software there is a front panel button (Boolean labeled "Disable Drive?") that disables the output from the state machine to the robot drive vi. Unfortunately the programmer got the wires mixed such that when "Disable Drive?" is true the output from said state machine is sent to the drive vi instead of zero. Thus when the robot is enabled and successfully grabs a can the operator raising both hands in triumphant celebration just misses his laptop as the robot proceeds to back away with it and the can. Breaker scenario: Simultaneously one pit over, team 9998 had a rough day yesterday. An old victor 888 gave out and they hastily replaced it with a gifted Tallon SR. They quickly prepare to power up the robot and upload code that initializes a Tallon instead of a Victor. A rookie student is ordered to pull out the breakers for the drive motors only and returns with 4 40 amp snap actions in his hand. With a glance at the PDB his Sr student is satisfied and orders the robot on. The robot then proceeds to take a nice long arc out of the pit directly into team 9999's runaway bot. What they hadn't realized is that yesterday they managed to hook up the Tallon's Motor +/- side into the PDB. Furthermore the rookie had removed two breakers for drive motors and two for the lift and not the one on the revered Tallon. TLDR? yes. Unlikely to happen next to each other? Yes. Completely improbable on their own? Not even. |
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#88
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Re: Safety Issue: Robots Moving in Pits
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TLDR; We personally found the removing breaker method to work for us, but I agree that the wheels being propped up is a failsafe way of testing mechanisms. |
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#89
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Re: Safety Issue: Robots Moving in Pits
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Keeping the safety rules simple and easy to understand and apply is real world industrial practice. The safest systems/environments are not the ones with "the best rules". They are the ones with effective rules that one can apply without referring to a manual when needing to apply the rule. Keeping a clear kill zone is also a standard industrial practice, especially in a dynamic environment where all kinds of new things are tried in a shared space making it difficult to foresee all possible hazards. We keep at least 6 feet away from equipment we are not familiar with in our production test areas and our R&D labs. This type of environment also makes it difficult to make detailed safety rules since the next project (or next year's game) can present hazards that we have not encountered before. In terms of preparing kids for the "real world", I would rather hire one who could think and devise a way to get the task done in a safe manner over one who just followed the rules since following the rules does not necessarily mean that one understands the logic and intent of the rules. |
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#90
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Re: Safety Issue: Robots Moving in Pits
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For example ... Lack of basic integration between hardware and software to ensure basic functionality works as-designed - Why is the team eager to test auto if they haven't performed even the basic tests for 'disable drive'? Unchecked electrical modifications by a rookie student - really, teams do this? That's more likely to cause a robot to go up in smoke than it is to cause a runaway robot. That's also a massive liability for the adults on that rookie student's team. It doesn't mean the adult does the work or even directly oversees it - rather, the adult checks the system before power is put to it. This two-party check (not 'glance') system is SOP for any maintained industrial electrical system before power is turned on. The two teams have to consciously agree that the system is safe. Testing a moving auto on the floor in the pits is a HUGE no-no. You're absolutely right - this should be off the floor - yet most teams with a safety culture already do this. Most teams with a safety culture also understand the futility of in-pit on-floor auto testing since the floor isn't the same as the carpeted field. |
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