AGV stopped picking items after awhile

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Glenson G asked Nov 9, '22 Glenson G commented Nov 14, '22

AGV stopped picking items after awhile

Hi @Felix Möhlmann ,

In this version of my model, there is a change in layout I have added more areas for delivery. I have also changed the area for the AGV staging area. May I ask for the Wait For Event CP, as it no longer travels unidirectional to the collection point, how do I prevent the deadlock from happening? (The AGVs stopped picking items after awhile)

Also, I would like amend the schedule where the AGVs will be collecting from different queues as well. How do I place the Wait For Event CP (if I have to), or do I have to make changes in the process flow?

Thank you!

liftusage-221109.fsm

Software Version:

FlexSim 18.2.3

agv agvpath agv elevator

liftusage-221109.fsm (1.6 MiB)

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Answer 1 · 2022-11-09T07:25:17Z

Felix Möhlmann answered Nov 9, '22 Glenson G commented Nov 14, '22

You can add more than one event to the "Wait for Event" activity, so that the token can continue regardless of the direction the AGV is approaching from.

When you have multiple queues to pick up from I would suggest to specify the triggering CP(s) per queue. For example through a label on the respective queues. You can then copy that label to the token once it knows where to drive and use that label in the 'Object' field, so that the activity only triggers when the AGV arrives at the specific point. (To prevent early triggers in case an AGV passes a different trigger CP on its way to a different queue)

At some point an AGV can't find a path because there is a piece missing on Lvl25 of Core3.

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Attachments: Up to 12 attachments (including images) can be used with a maximum of 23.8 MiB each and 47.7 MiB total.

Glenson G commented · Nov 09, 2022 at 09:18 AM

Hi @Felix Möhlmann ,
liftusage-221109-2.fsm

I have rectified the path on Lvl 25 on Core3

I have tried to add one "Wait For Event" for my next event which is loading trolleys from the upper levels to the KitchenReturn queue but I don't seem to be able to resolve it.

And my apologies that I don't quite get the second part of your explanation. You mean to create more labels in the "LoadObject"? But it is now branched out for a path for if it goes to B1. How can it be applied to all the other queues?

Thank you Felix!

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liftusage-221109-2.fsm (1.6 MiB)

Felix Möhlmann Glenson G commented · Nov 09, 2022 at 10:09 AM

Both the KitchenCollect and KitchenReturn queue get different label values, so that the CP the AGVs have to arrive at depends on which queue they are travelling to. The reason why I would to this, is AGVs travelling to the Return queue from the right also trigger the CP of the collect queue, allowing them to prematurely pull a loadCP.

I have added the changes to the attached model.

liftusage-221109-3.fsm

The next thing you should look at is that the 'Return-Trolleys' are being send to the sinks 300s after they are created. The missing items then break the AGV tasks.

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liftusage-221109-3.fsm (1.6 MiB)

Glenson G Felix Möhlmann commented · Nov 09, 2022 at 11:59 AM

Hi @Felix Möhlmann ,

From the same model, if I have a pick up at MMD (one of the queues near Core), do you mean to create new tokens (like in the screenshot below) at both branches in the process flow? Would that work?

May I ask what do you mean by the missing items break the AGV tasks? As I thought that at 7200s, there will be trolleys populating at the queues in the upper levels which would activate the AGVs regardless of the items that are unloaded onto the queue being sent to the sink.

Thank you very much @Felix Möhlmann !

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