question

Claire Krupp avatar image
0 Likes"
Claire Krupp asked Claire Krupp commented

Need help with stopping AGV gridlock.

I have a large AGV network, and recently added some new spurs for parking. I keep getting gridlock around the area where the parking spurs are. I've tried extra control areas, control points, spacing etc. and this keeps happening:

1674080191542.png

The AGV on the left has not even reached the next control point, but it has already allocated two path junction points which are further ahead, so that the AGV on the right cannot move out of the spur, even though it has allocated the control point to the right.

Is there any way I can change this "look ahead" allocation behavior? I've tried so many permutations and it just keeps happening!

Thanks.

FlexSim 23.0.1
agv allocationagv gridlockpath junctions
1674080191542.png (83.3 KiB)
5 |100000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 12 attachments (including images) can be used with a maximum of 23.8 MiB each and 47.7 MiB total.

1 Answer

Felix Möhlmann avatar image
0 Likes"
Felix Möhlmann answered Claire Krupp commented

Anthony's answer to this older post might help with finding a solution.

In short, while the allocation of control points happens on the PreArrival event of the previous control point, the allocation timing of transfer points depends on the "Intersection Stop Point" values that are set for the accumulation behaviour. (The AGV will try to allocate the transfer point at a time, so that i could come to a stop at the specified distance).

1674113590728.png

Moving the control point at the intersection entry back or reducing the stopping distance so that the control point at the exit is allocated before the transfers should fix the deadlocks.

Alternatively, version 23.0 introduced the possibility of handling deadlocks by returning a 1 in a deadlock "OnAllocationFailed" event.

1674113578944.png

In this case, you could try to preempt both AGVs to stop at their current control point. Then resuming one and after it has cleared the intersection resume the second one.


1674113578944.png (12.8 KiB)
1674113590728.png (6.0 KiB)
· 2
5 |100000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 12 attachments (including images) can be used with a maximum of 23.8 MiB each and 47.7 MiB total.

Claire Krupp avatar image Claire Krupp commented ·
Thanks for the explaining how it works @Felix Möhlmann . I'll try to reduce the number of control points and see if that helps.

The deadlock recovery looks possible too, though more complicated!

0 Likes 0 ·
Claire Krupp avatar image Claire Krupp commented ·
I took out some control points and moved things around a bit, and now it works perfectly!

Thanks @Felix Möhlmann

0 Likes 0 ·