Singularity threshold during EGM

csmith

Hi, 

I've done a few tests in RS as well as on a real robot and I'm getting inconclusive results. I've seen the robot fault ~25° before an actual singularity and sometimes I can get as close as ~3°.
Fault is always 50456 'Close to singularity while External Motion Interface active'
I get similar results jogging the robot with the Pendant as well as controlling it through EGM. 

Is there a defined angular limit at which the robot faults due to being near a singularity? Is that limit adjustable?
I'm mainly concerned about joint 3, and would like to monitor the angle to avoid singularities.


Thank you

lemster68

There are singularities other than axis 5 near 0 degrees.  And since you mention axis 3 I have to think of another singularity which is the wrist directly above axis 1.  Is this the case?

csmith

I mean the singularity whenever the first arm(between J2 and J3) and second arm (between J3 and J5) are parallel. 

csmith

lemster68

Ah, the other one.  Is this simulation only or real robot?  You are not only in singularity there, but pretty much running out of reach.  Nearing the limits is probably part of the cause.  Can you get a longer arm or change the EOAT?

csmith

I see this both, during a simulation as well as on the real robot. I'ts true that I'm close to out of reach, but it's still faulting with a Singularity fault.
I'm looking for some information on what joint angle limit the robot considers a singularity, and if that is adjustable.
Thanks

jakobhoerbst

I have a similar problem. I get very fast into a singularity with EGM (axis 5 -> 0). I have already tried with SingArea to fix the problem, but the function seems to have no influence. 

Also the 'classic' error handling does not work with EGM (e.g. for axis limits). Is it possible to catch the errors somehow so that the control does not jump to "stop"?