How to recalculate the route after establishing a path for a deadlock in an AGV?

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Choi Hyun Woong asked Jul 17, '23 Choi Hyun Woong commented Jul 26, '23

How to recalculate the route after establishing a path for a deadlock in an AGV?

Hello, I have several questions about AGV.

TaskExcuter1(TE1) is going to CP4 from CP1.

TaskExcuter2(TE2) is going to CP1 from CP4.

CP8 and CP9 are both control points on the shortest path between TE1 and TE2.

TE1 and TE2 are deadlocked for TE2 to allocate to CP8 after TE2 arrives at CP9.

Set CP8 to the block state (AGV.RoutingConstraint.Blocked) and recalculate the path in TE2.

The calculated route is the path from CP4 to CP1 without going through CP8.

(The content has been revised.)

That path is not the shortest route.

I want the TE2 to go from CP7 past CP8 to CP1. (That's the route around deadlock I want.)

Question1) How to recalculate the route after establishing a path for a deadlock in an TE2?

In addition, I have a question about "Route Around Deadlock" codes.

Question2) Why is the 71th command not being executed?

await preemptAGV.te.event("OnAGVPreAllocate");

The above command was not executed, so I did it with the command below.

await Delay.seconds(0);

RouteAroundDeadlock1.fsm

Software Version:

FlexSim 23.1.2

agvrouting

1689578039203.png (30.7 KiB)

1689580497817.png (30.5 KiB)

1689581214623.png (37.6 KiB)

routearounddeadlock1.fsm (68.2 KiB)

· 2

Kavika F ♦ commented · Jul 18, 2023 at 02:54 PM

Hey @Choi Hyun Woong, I can't seem to open the model you attached. Could you please reupload it? I have some ideas about what could be happening but it would help to confirm with your model. Thank you!

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Choi Hyun Woong Kavika F ♦ commented · Jul 19, 2023 at 04:09 AM

Thank you! I did reupload model.

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Answer 1 · 2023-07-19T15:50:19Z

Kavika F answered Jul 19, '23 Choi Hyun Woong commented Jul 26, '23

Hey @Choi Hyun Woong, for your first concern of the AGV not taking the shortest path, I believe it's because of the location of the Control Point 7 (CP). The paths were arranged in a way that the CP was on the curved path rather than the intersection between the 3 paths. If you adjust the paths and CP slightly, you can see the correct behavior.

routearounddeadlock1_1.fsm

As for your second question, I am a little confused. The line you're talking about was commented out, so it would not execute. After uncommenting the line and commenting out the other await you added, it seemed to work fine. Is there something I'm missing? Thank you.

correctedcp.gif (471.6 KiB)

routearounddeadlock1-1.fsm (68.5 KiB)

· 5

Choi Hyun Woong commented · Jul 20, 2023 at 02:32 AM

Thank you for your reply.

The model you uploaded has the CP8 slightly moved to the CP9. Therefore, CP8 is no longer an intersection.

The crux of the problem is how to ensure that TE2 are allocated CP8 in the event of situation in which the deadlock is resolved. (TE1 are deallocated CP8)

My idea is to recalculate the route when TE2 arrives at another CP.

Upload a model with the logic I think.

If you have any other ideas, please suggest them.

RouteAroundDeadlock1-1.fsm

And Question2 is resolved.

The command below is also executed in my uploded model.

await preemptAGV.te.event("OnAGVPreAllocate");

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1689821356901.png (31.3 KiB)

routearounddeadlock1-1.fsm (69.5 KiB)

Kavika F ♦ Choi Hyun Woong commented · Jul 20, 2023 at 07:44 PM

This certainly is one way to ensure CP8 is allocated; however, I don't know how scalable this would be.

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Choi Hyun Woong Kavika F ♦ commented · Jul 20, 2023 at 11:15 PM

You are correct.

The algorithm I thought might not work in certain situations.

So I'd like to know if anyone has a general algorithm that is scalable.

Thank you!

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