Why AGV won't pull finished item from list?

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question

Emily K asked Jan 4, '23 Jason Lightfoot edited Jan 5, '23

Why AGV won't pull finished item from list?

Item flow: Buffer4 > QueueIn > Processors > QueueOut > Buffer5

1. Processors find material > assign destination using activity Assign Labels > Push to list > Decide whether QueueIn has capacity (queue capacity = 50). If QueueIn don't have capacity, Processor won't find material.

2. AGV loads items(with label <Type>, value=0) from Buffer4 and send to destination based on their destination label.

3. After AGV finished unloading, it will return to home point.

4. Check if there are finished items.

5. Travel to QueueOut which has finished items and send them to Buffer5.

I was stuck at Step4, could anyone give some advices, please?DEMO_230104.fsm

Software Version:

FlexSim 21.2.4

process flow pull from list

demo-230104.fsm (118.4 KiB)

Answer 1 · 2023-01-04T14:10:41Z

Kavika F answered Jan 4, '23 Jason Lightfoot edited Jan 5, '23

Hey @Emily K, I think I have a solution that may work for you. I mainly made changes in your AGV Object Process Flow.

First, I changed your "Is there any FinishedItem" activity to rearrange the ranks of the connections. You originally had the first connection going to the left and the second going down (like the screenshot says). I flipped it so path two went to the left and path one went down. Then I made sure that failed requests went down path two (to the left). I believe that your tokens were just going down path one regardless of failure or pass.

Then I simply changed your Travel activity to go to the FinishedItem.up. That way it would go to the queue the item is at. It was struggling to find the item itself.

(Note, I disconnected Buffer5 from the sink so I could watch finished items go in)

agv-find-finished.fsm

1672841367409.png (13.0 KiB)

agv-find-finished.fsm (118.7 KiB)

1672841286732.png (13.7 KiB)

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Emily K commented · Jan 05, 2023 at 02:59 PM

Thanks for help!
Could I ask what is the difference between token.item.up and up(token.item)?

I found it weird that it will stop at 8000s, but when I click play, it can resume.

When there is finished items enter the list, AGV will travel to the finished item related QueueOut. I wish agv could load more finished items (maximum 4) if the QueueOut has other items.

I first add a label origin in process flow of QueuOut.

Then, in agv process flow, I add a decide activity to check if agv has capacity, if yes it will pull finished item from the list which has the same origin with current queue.

I add one more query in the pull from list: Origin = token.FinishedItem.up

But it pop out an exception
Then, I find some questions related to mine: https://answers.flexsim.com/questions/115023/pull-same-item-type-as-before.html
I could find the item labels in the tree, but having a problem on how to get the property. Luckily, I find a code reference to the content container, but not sure if the code is correct or not. Hope you could give me some help! DEMO_230105.fsm

current.attrs.first.Origin == FinishedItem.Origin

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1672929365677.png (12.0 KiB)

Jason Lightfoot ♦ Emily K commented · Jan 05, 2023 at 03:43 PM

It stops at 8000 because the model has a stop time defined for then.

The error at 8124.17 is due to referring to token rather than puller in:

WHERE Type = 1 AND hasDestination = 1 AND Origin = token.FinishedItem.up

Note that 'distance' can't be used while the puller is a token - you should use the agv for that.

The command up() is deprecated but gives values that match the treenode's up property.

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