question

pc neo avatar image
0 Likes"
pc neo asked pc neo commented

A*Star warehouse picker travel node data

We are working on a warehouse model using A*star and needed to get the information of the following:

a) the path each picker has travelled.

b) congestion in any area at any point of time.


Reviewing the post on forum we noted that information may be extracted from "AStarNavigator>stats/extraData" treenode (https://answers.flexsim.com/questions/54528/heat-map-gradient.html). However, the totalTraversal does not suits our need. We have noted data of our interest is in node "AStarNavigator>variables/travelmembers/Operator7" treenode. It has a list of travelpath and allocations. We have a sample model created attempting to get the allocations but it seems that it only records partial of the information. Is the way attempted in the model is not right?


The sample model has flowitems created into racks and assigned operator/forklift to pick it and send to a floorstorage. As A*StarCalculatePath event happens we will attempt to call getAllocations() and travelPath from the AStar.Traveler object. In this sample a token at time 10.86 sec the A*StarCalculatePath event happened, it is noted that allocations recorded does not include the later nodes beyond time 12.27, though the node "AStarNavigator>variables/travelmembers/Operator7" has the information.

screenshot-2024-11-21-112227.png

How to get the data?

FlexSim 24.2.2
warehouseastar navigator
· 2
5 |100000

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

Jeanette F avatar image Jeanette F ♦♦ commented ·

Hi @pc neo,

Were you able to solve your problem? If so, please add and accept an answer to let others know the solution. Or please respond to the previous comment so that we can continue to help you.

If we don't hear back in the next 3 business days, we'll assume you were able to solve your problem and we'll close this case in our tracker. You can always comment back at any time to reopen your question, or you can contact your local FlexSim distributor for phone or email help.

0 Likes 0 ·
pc neo avatar image pc neo Jeanette F ♦♦ commented ·
@Jeanette F Thanks for checking. No, I am still unable to get the data that I need.
0 Likes 0 ·

1 Answer

Felix Möhlmann avatar image
0 Likes"
Felix Möhlmann answered pc neo commented

The travel path does contain all nodes that are part of the route. When "Deep Diagonals" are allowed in the A* navigator a cell that can be reached by moving two cells in one direction and one cell perpendicular to that counts as a 'neighbor' to the starting cell (think of how knights move in chess). The cells in between will be allocated during the travel but are not technically part of the route that was calculated.

The missing nodes could be inserted manually by comparing the row and column of the current and the next cell. If they differ by more than one, add entries for the cells inbetween to the table. These obviously won't have an arrival time though.

Which leads me to the next point. Depending on what you define as "congestion", on option might be to store times a traveller became blocked.

note-block-times.fsm

On the OnContinue event, you could then also read the travel path again to update the expected arrival times.


note-block-times.fsm (638.3 KiB)
· 1
5 |100000

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

pc neo avatar image pc neo commented ·

@Felix Möhlmann Thank you for your clear explanation. Your suggestion can be useful in the scenario that I am working.

0 Likes 0 ·