question

Chema Vecino avatar image
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Chema Vecino asked Jason Lightfoot commented

AGVs network optimization

AGVs.fsm

Hi! Kind of new to FlexSim so excuse me for any lack of knowledge.

So I'm working on a AGV network that must be able to attend all loads/unloads without bottlenecks by using as few AGVs as possible.

I've already done the PF and it works fine, I think the problem I'm having is the network itself. In the model attached, when using 8 AGVs, everything runs smoothly but I get a few bottlenecks, and if I add more the AGVs start getting blocked. I've tried multiple variations of this network and I'm not being able to find the optimal solution.

There is probably some FlexSim function or premise when designing networks that I'm not aware of, because I've spend plenty of time working on this model.


Any help would be much appreciated.

FlexSim 24.0.0
agvnetwork
agvs.fsm (102.4 KiB)
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Jason Lightfoot answered Jason Lightfoot commented

You should see that one of the blockages is happening when it should not at the Carga1 station. This is because the distance between the Carga1 and Carga2 control points is less than 3 metres and the model has the AGV stop threshold set to 1metre between the AGVs (trailing to leading edges) with the 2metre AGVs stopping at their mid points - which means you need 3 metres between points.

You can either move the control points further apart or change the stop threshold:

1702821856008.png


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Chema Vecino avatar image Chema Vecino commented ·
I haven’t notice that problem, thanks!!

The main problem though is the bottleneck in the Carga5 queue, I’m guessing it’s due to the network itself because of the difficulty to get there for the AGVs.

Is there something I’m not doing in terms of common practices? For example, I’m not sure if I should use a detour in front of the queues so the main path is not blocked, or add more control points, or…

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Jason Lightfoot avatar image Jason Lightfoot ♦♦ Chema Vecino commented ·
You can add more control points so that the blockage doesn't work its way back up the network so far - they allow the AGV to move closer to the target CP, or you could make some of the non-accumulating paths accumulating.
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Chema Vecino avatar image Chema Vecino Jason Lightfoot ♦♦ commented ·

AGVs_2.fsm

Ok, so I made a few changes and the model starting working better (less bottlenecks). At some point I changed something and now the AGVs get stuck at getting parking spots assigned, but I can't figure out why.

Any thoughts?


Also, at some point, they get blocked in the path that joins all parking spots.

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agvs-2.fsm (108.3 KiB)
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