Author Topic: Question about Protective Stop and Base setting  (Read 161 times)

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Offline Dlinki

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Question about Protective Stop and Base setting
« on: November 07, 2018, 08:53:56 AM »
Hello everyone,

I'm kinda new to the Robotic world, and I'm doing an internship in the domain of the collaborative robotic.

I have two problems and I've tried really hard but I don't find the solution.

      1-  Running a lot of tests to measure the force of the robot, I have to manually switch the Safety mode from Protective Stop Mode to Normal mode then have to restart or continue the program. But doing it manually is very time consuming and sub-efficient
           
           What I'm seeking for is a way to automate the tests. What would be great is a way to automatically continue to run the program after the shock, so the robot would hit the sensor, switch to protective stop and the robot itself (or an external device if needed) would switch from Protective Stop to Normal mode and continue the program.

      2- In Polyscope, there is a MoveL command, it's an easy to use command, but it's not possible to increment a variable in there. So I've used the Script command movel(). But there is a problem here. Indeed, in the MoveL from Polyscope, we can use a feature space just by choosing it in the feature menu. But in the Script command, there is no information about a feature space setting. So of course, when I run the program (in Simulation) it doesn't go as expected.
          Do you know how to set a feature space when programming the movel() in Script ?

I hope what I'm asking is not impossible, cause it would help me a lot.

Thank you

PS : It's a UR10
« Last Edit: November 07, 2018, 09:02:02 AM by Dlinki »

Offline ClaudiuA

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Re: Question about Protective Stop and Base setting
« Reply #1 on: November 09, 2018, 10:11:40 AM »
Protective Stop is, as the name implies, a PROTECTIVE stop. The robot stops to protect itself and OTHERS. You are bashing the robot against an obstacle. Why would you think anyone would allow a robot to restart automatically after what is considered an accident?! "I have hit a person in the head with this sharp tool I'm carrying in my gripper. Let's hit him again and see if something else happens this time around".  :icon_smile:
I'm not being sarcastic, but what you're asking is a blatant disregard for safety. Even if the robot is collaborative, you still need to respect some basic safety rules.

Yes, it is possible to increment a variable in a MoveL but I don't really understand what you're trying to achieve there.
Why do you need to use a particular feature for the movement? It would help if you explain what you're trying to achieve.


Offline Dlinki

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Re: Question about Protective Stop and Base setting
« Reply #2 on: November 09, 2018, 12:35:00 PM »
Hey. First of all thank you for the reply.

So te be clear, this is safety related tests. I'm running a battery of test and there are a lot of different inputs. There is a bench and a force sensor dedicated to the tests.

I know it's kinda weird to ask that, but my goal is to run like 20 shocks in a row with different speeds, so I can map the force of the robot. And I repeat this operation in a variety of configuration (Z+, Z-...).

So for every tests, I need to switch the Safety Mode, like everytime.

I was hoping there is a way to run tests in a row without a human operation in between to switch the Safety mode




Offline ClaudiuA

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Re: Question about Protective Stop and Base setting
« Reply #3 on: November 12, 2018, 01:53:16 PM »
I think you are a bit confused.

Protective Stop is NOT a safety mode. It is a collision error. It is a forced stop. Which is why you can't normally just continue as if nothing happened.
Safeguard Stop and Reduced Mode are what you are referring to as "safety modes".

We ran the same kind of tests with a PILZ representative a while back and every stop has been a shock stop that required us to restart the robot and rerun the sequence, manually.
You can, theoretically, force a signal to enable the robot after a shock but you need a bit more knowledge of programming - scripting - than I know at the moment.

You could, however, just create a small routine that would send the robot back to its initial position. So after you get the shock, you just enable the robot, press stop and then play. In theory you should be able to get a routine running that won't need much from you except 3 button presses.

Offline Dlinki

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Re: Question about Protective Stop and Base setting
« Reply #4 on: November 13, 2018, 08:08:15 AM »
Yeah I might not be using the right terms, as I'm really new to this domain.

Ok So I would just send the robot back to his initial position in the "Before Start" (or Before something) part ?

Anyway thank you a lot for your time.

PS: So I managed to to the routine you told me in the last message, I used get_actual_tcp_pose() so I create a variable that takes the actual position and move there. So it begins the program without auto !



« Last Edit: November 13, 2018, 08:35:38 AM by Dlinki »

Offline ClaudiuA

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Re: Question about Protective Stop and Base setting
« Reply #5 on: November 13, 2018, 11:43:23 AM »
Ohhhh, that was your problem, actually waiting for the robot to move its hiney back into position while you kept the button pressed   :icon_mrgreen: . Yeah, that is a pain in general and I had to instruct a lot of clients to just add a read current position instruction to the start of the program.

Hope that helped your problem then.

Offline Dlinki

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Re: Question about Protective Stop and Base setting
« Reply #6 on: November 13, 2018, 12:42:05 PM »
That was a part of my problem, yes.

But I will give up on the automation of the Protective stop enabling.

You helped me well, and that's a bit better now  :bravo: