AGV Simulation Issue: Navigation Error

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Glenson G asked Oct 5, '22 Glenson G edited Oct 11, '22

AGV Simulation Issue: Navigation Error

Hi there,

The purpose of my model is to see how many elevators are sufficient for the certain number of volume of AGV trips. However, I would encounter this error after running for awhile.

I would appreciate any advice on how to run this model smoothly (be able to deliver to all floors and return to the parkpoints when job is done)

Thank you very much!
liftusage-1.fsm

Software Version:

FlexSim 18.2.3

agv agvpath agvs agv elevator

1664964216084.png (19.2 KiB)

liftusage-1.fsm (874.0 KiB)

Answer 1 · 2022-10-05T11:19:18Z

Felix Möhlmann answered Oct 5, '22 Glenson G commented Oct 6, '22

Building an AGV network can sometimes be finicky. In the case above the cause is that the connecting path between level 8 and the base level is only a one-way path. I also noticed that some levels are missing a connecting path that allows the AGV to turn back onto the loop after it has dropped off its cargo.

Generally, the only thing you can do with that error message is check where the AGV and its destination CP are located and search the path between them for any errors/missing links.

One thing that might save you some headache could be to only use a single CP as park point for now (increase max. allocations so that all AGVs can occupy it at once). All of the parking paths connecting to a single point on the main loop is prone to errors.

1664968553953.png (18.4 KiB)

· 7

Glenson G commented · Oct 05, 2022 at 02:01 PM

Thank you Felix. I have tried connecting the paths in the other levels as well as changing into just one park point with increased allocations. The same error still occur. it seemed like it was one of the pick up control points.

Tried to have a different paths for drop off at level 8 but it still does not work. Would need your advice on this. Thank you!

liftusage-1.fsm

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liftusage-1.fsm (865.5 KiB)

Felix Möhlmann Glenson G commented · Oct 05, 2022 at 02:53 PM

As I mentioned, the path between level 8 and the base level is set to allow only travel in one direction. So the AGV can't return from level 8.

Changing that and removing the requirement to pull a park point from the list (since there is only one now) made the model run until completion. There are still exception with the OnEntry trigger of the queues though. I can see that they are supposed to move something after a delay. But the settings don't make much sense (centerport references that don't exist).

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Glenson G Felix Möhlmann commented · Oct 06, 2022 at 01:34 AM

My apologies that I missed that out. Thank you very much Felix! I managed to run the model till completion.

The model was suppose to simulate the AGV returning the item delivered after a certain timing. I have made amendments and I think it's good. Appreciate your help deeply Felix.

liftusage-1.fsm

May I ask what is the difference between using the A ports and the S ports between a queue and a sink?

May I also if it is possible to toggle the activation and deactivation of the elevators? I would like to be able to disable elevators to see the overall utilization of the lifts if I reduce/increase the number of elevators.

Thank you very much for your help and guidance!

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liftusage-1.fsm (867.2 KiB)

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