Measure Stop Time

    Hi!


    KRC4 Compact 8.3.22

    KR6 R900 sixx


    I'm looking for a way to determent stop time for axis 1-3 to get the right safety distance for a laser scanner when we run at a safe speed.

    The robot mentioned above is only my test robot at the office, not the one to be used in production (it will have safe operation).


    Is there some good way of doing this with the built in oscilloscope?


    Getting the signal when the safe stop is triggered and when the axis is stand still?


    Or how do you do it?


    Thanks in advance!

    Edited once, last by edda ().

    You need the same type of robot.

    You need safe operation.

    Create a safe border somewhere in the working range.
    Make program that moves through that border.

    Start program in auto with slow speed and note the position after stop of the robot.

    Do the same with full speed and calculate the difference.

    Hi Herman,


    Thank you for your response.


    Won't that only give me the difference in stop distance based on the speed, not the actual time needed to stop?

    Please correct me if I´m wrong.


    I'm thinking based on EN ISO 13855, if I know the stop time (including the response time on the logic, e.g. scanner and code) I can calculate the needed distance to the robot.


    Best Regards

    Edited once, last by edda ().

    Well I'm not quit sure that you follow me here.


    I need to determent the stop time it takes for the robot to stop moving at a certain speed (reduced velocity, not full) when the safe stop occurs.

    When a person enters the yellow zone the robot slows down to reduced velocity.


    Based on that I should be able to calculate how big the red area should be in the picture.

    And also measure how fast it reaches the reduced velocity to know how big the yellow zone needs to be.


    you can use camera to record video, or just use built in Trace to see how long it takes for robot to stop.


    btw. that is one big KR6 R900 sixx

    1) read pinned topic: READ FIRST...

    2) if you have an issue with robot, post question in the correct forum section... do NOT contact me directly

    3) read 1 and 2

    Haha Yes Panic Mode you are right, that´s one big KR6 😊

    I will be using a K360 R2800 in the project, but the KR6 is in my office for purposes.


    I tried using the Trace function but I couldn't find and signal saying that the safe stop i active to get into the trace.


    I selected the Tracedef_AT_BrakeTest_KSS configuration as a base.

    And in the Advance Configuration Tab I added the Module CabCtrlSafetyDiag -> Safety Diagnosis Signals, but nothing from there shows up in the Scope after I recorded a Trace (Only the Standard Configuration gets recorded).

    My first post was a quick shot, without catching the task.

    May be the second wasn't good enough explained. Second try to explain:

    Mount the laser scanner in a way that the robot himself can trigger it. Then let the robot trigger the scanner with different speeds and log the positions where he stops. You can see the difference of the faster movements to a very slow one as the reaction path. Think that is what You need, if not, I really didn't catch the task.

    A Trace should be able to trigger any general fault state -- basically, "if any system fault is active, trigger".


    Setting the time divisions up to record slightly "upstream" of the trigger event, as well as downstream, should let you get very good data for how long each axis takes to come to a full stop.


    One caveat: you'll need to test this with the actual working payload, at the safety-limited speed, and do multiple tests at different robot poses, because the stopping time will change. Hopefully, the safety-reduced "yellow zone" speed will reduce the variance you see in the stopping times, but you need to carry out tests to confirm this. And, of course, use the worst-case stopping time for your safety distance calculations.


    The test needs to trip the robot safeties in the same way that the safety device will -- the difference between Category 0, 1, and 2 stops matters here.


    You also cannot ignore A4-A6. They can take surprisingly long to stop, especially for a heavy payload with a CG well out from the faceplate.

    way too broad... there are so many robots. most are 6 axis. that alone is plenty of diversity. add to that infinite number of paths robot could take and that each axis can run at different velocity, robot can have different loads that may or may not be set correctly etc. in practical terms it is infinite number of possibilities which is why taking measurements in specific application is the only way to address this.

    safety circuits are not the same, response of a single safety relay can add 20-45ms (see Bulletin 440 from AB for example). for a robot moving some 2m/s that adds several inches of travel before robot even knows that it should be trying to stop. and that is a single relay. even simplest cells usually have few of them so half a meter just because of response time of the safety circuit. robot itself may take second or two to stop. if the event also causes failure, things could be even worse. which is why any safety review involves measurements and calculations. this involves stopping distances, response time, failure rate of each component...

    1) read pinned topic: READ FIRST...

    2) if you have an issue with robot, post question in the correct forum section... do NOT contact me directly

    3) read 1 and 2

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