Traveller AGV with proximity detection will not continue travelling

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bnh-flexsim-for-masterthesis asked Feb 17, '23 bnh-flexsim-for-masterthesis commented Feb 17, '23

Traveller AGV with proximity detection will not continue travelling

Dear All,

I have currently created a simple intersection modell with agent proximity detection. It seems fine, the AGVs stop at the defined proximity thershold, but in some cases, the AGV will not move again after exiting the proximity threshold of other AGVs, causing a blockade of the intersection.

I am not sure what causes this issue, so please find the modell attached.

Thank you and kind regards

First_Intersection_AMR.fsm

Software Version:

FlexSim 23.0.3

a star proximity agent system

first-intersection-amr.fsm (37.5 KiB)

· 2

Ralf Gruber ♦ commented · Feb 17, 2023 at 02:29 PM

Hello Bjarne,

you should at least explain the functionality you try to achieve and put explanatory comments in your source code on the Behavior tab triggers to motivate people to help you ;)

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bnh-flexsim-for-masterthesis Ralf Gruber ♦ commented · Feb 17, 2023 at 04:58 PM

Dear Ralf,

I took the source code from the TwoPhaseAGVSystem.fsm in the Agent Module Example Models by anthony johnson in an article from the FlexSim community under the following link and implemented the code in my model.

https://answers.flexsim.com/articles/84495/agent-module-example-models.html
I am aware that the code is not fully applicable to my model, but i took it as a first idea to get my model running.

For my specific requirements it need some adjustments for sure.

What i am trying to achieve is a proximity functionality which detects all AGVs entering the proximity boundary of an AGV.

If an AGV enters the boundary between 0° and 90° (in which 0° should be the direction of driving and 90° should be the right side of the AGV), the current AGV (1) needs to stop, until the AGV entering the boundary (2) has left.

kind regards :)

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proximity-boundary.png (4.2 KiB)

Answer 1 · 2023-02-17T14:59:14Z

Ralf Gruber answered Feb 17, '23 bnh-flexsim-for-masterthesis edited Feb 17, '23

It seems, you have a timing issue:

at roughly 45s TE5 fires the Broad Phase Proximity Entry trigger at TE1

at roughly 46s TE6 fires the Narrow Phase Proximity Entry Trigger at TE1

at roughly 48s TE5 fires the Broad Phase Proximity Exit Trigger at TE1

This switches off Narrow Phase behavior for TE1 and therefor TE6 leaving the Narrow Phase is not detected and TE1 is stuck in STATE_UTILIZE

Your logic does not consider more than 2 TEs overlapping.

Good Luck

· 1

bnh-flexsim-for-masterthesis commented · Feb 17, 2023 at 03:17 PM

Thank you Ralf,

is it possible to add a counter to the logic? so that the Narrow Phase behavior only gets switched of if number of exits match the number of entries?

additionally, there might be a situation in which two TEs come to a deadlock.
they are facing eachother at 90° angle and stop, because none of them has a priority.
Is there a way to correct that issue?

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