AGV offset travel issue

Question

question

Alessio Merlo asked Oct 18, '21 Ryan Clark commented Oct 21, '21

AGV offset travel issue

Hi,

while stopping randomly an agv during its task, a navigation error occurs.

I reproduced the behavior in the attached model. agv_offset_travel.fsm

The model logic is simple:

1. agv receives standard task from source;

2. process flow listens the CP - OnPreArrival event;

3. when the event is triggered, after a while the agv is stopped before reaching the control point;

4. on resume object the error occurs.

I can simple avoid the error changing the agv configuration (from "use navigator for offset travel" to "do not travel offsets for load/unload tasks".

I mean that after resuming the agv, it believes to reach the destination because it is really close, but it isn't close enough for unload task.

What do you think?

Software Version:

FlexSim 21.2.3

agv offset travel

error.png (4.4 KiB)

agv-offset-travel.fsm (36.3 KiB)

· 1

Ryan Clark commented · Oct 21, 2021 at 06:36 PM

Hi @Alessio Merlo, was my answer helpful? If so, please click the "Accept" button at the bottom of my answer. Or if you still have questions, add a comment and we'll continue the conversation.

If we haven't heard back from you within 3 business days we'll auto-accept an answer, but you can always unaccept and comment back to reopen your question.

0 ·

Answer 1 · 2021-10-18T15:57:46Z

Ryan Clark answered Oct 18, '21 Ryan Clark commented Oct 18, '21

Hi @Alessio Merlo,

I think the problem is that sometimes in your process flow, the AGV stops within an area where it's too close to "travel" to that CP anymore, so it throws that error to indicate that. I was able to solve the problem by adding other control point directly before the one that's having issues and listen to the Pre Arrival event of that CP. That fixed the problem to show the presumed desired logic of the model.

If I may ask, what is the objective you're trying to accomplish with this setup in your full-size model. That would be helpful in us answering any additional questions you may have.

Let us know. Thanks!

· 2

Alessio Merlo commented · Oct 18, 2021 at 04:15 PM

In the full-size model I would like to stop randomly the agv without exception.

I reported you the issue because I believe that it is a bug or internal issue created when FlexSim 20.1 is release.

It is very similar to this topic:

https://answers.flexsim.com/questions/85347/exception-when-resuming-an-agv-which-was-stopped-d.html

My model would isolate the issue in order that you can debug it easily. Could you report this to @phil.bobo or @anthony.johnson? Thanks!

I attached another model to show my real case. Instead of process flow, in this model an MTBF/MTTR stops randomly the agv. The error is the same.

agv_offset_travel_2.fsm

0 ·

agv-offset-travel-2.fsm (32.5 KiB)

Ryan Clark Alessio Merlo commented · Oct 18, 2021 at 06:03 PM

Hi @Alessio Merlo,

I submitted a case to the dev list. Thanks for pointing this out!

@Phil BoBo @anthony.johnson

0 ·

question