Warehouse atom

All topics on the Atoms in any Enterprise Dynamics Library.
Katinka
Posts: 23
Joined: Thursday 14 June, 2012 - 08:42

Warehouse atom

Post by Katinka »

Hello,

I’m working on a simulation of a warehouse with multiple storage racks and aisle-changing high rack stackers.
I thought it would be a good idea to use the warehouse-atom for a storage rack, and an advanced transporter-atom to represent a high rack stacker.

However, the time it takes to store a pallet does not depend on the storage position within the warehouse:

The advanced transporter continuously lifts up the pallet to maximum height, even though the pallet should be placed at ground level? (I used labels to determine the position in the warehouse)

Furthermore, I would like to have the transporter drive to the k-th column of the warehouse whenever a pallet needs to be placed there, instead of just driving to the front end of the warehouse and ignore the driving distance (since the rack equals 138 meter in practice, this is important). I tried to do this by means of a network, but it does not work out when I connect multiple network nodes to one atom. The only thing I can think of now, is using 138 warehouse-atoms consisting of 1 column? But a warehouse/advanced transporter function I don’t know about (yet), would be nicer 8-)

Thank you in advance,

Katinka
marlies
Posts: 301
Joined: Monday 17 January, 2011 - 09:28

Re: Warehouse atom

Post by marlies »

Hi Katinka,

Did you have a look at the example models for the advanced transporter? These models are available in the work directory of ED. One of them is the model WarehouseWithAdvancedTransporters.mod which contains the functionality you describe. You could compare your settings to this model, to find out what's going wrong. It should not be necessary to add 138 racks of one column :-).

Regards, Marlies
Katinka
Posts: 23
Joined: Thursday 14 June, 2012 - 08:42

Re: Warehouse atom

Post by Katinka »

Hi Marlies,

Thanks for your answer, I'm glad I didn't need to add 138 racks ;)

I'm now trying to extend the model by introducing bufferlocations.
I have two types of trucks in my model: APM and Combi trucks (both represented by an Advanced Transporter).
An APM transports a product from the source to a bufferlocation (represented by a Warehouse Atom).
A combi transports a product from the bufferlocation to the associated storage rack (also represented by a Warehouse Atom).

APM trucks make use of network 2 and Combi trucks of network 1. These networks do not overlap, except for the fact that both networks are connected to the bufferlocations. There it seems to go wrong, because when I use Network Controller 1 to optimize network 1, also connections in network 2 are changing. And vice versa.. It looks like it can never find an optimal network?
If I optimize network 1 last, I get the error message: " 4DScript: error at "Do": Access violation at adress 0086FEB0 in module 'ED.exe' read of address 000001D5. "
If I optimze network 2 last, it seems that the Combi truck get stuck after a few products (exactly when it needs to transport something to warehouse 1). Maybe I used the wrong logics there?

I added the model in the attachment.

Kind regards, Katinka
Attachments
06-25.mod
(70.9 KiB) Downloaded 501 times
marlies
Posts: 301
Joined: Monday 17 January, 2011 - 09:28

Re: Warehouse atom

Post by marlies »

Hi Katinka,

The problem is that atoms can be connected to only 2 nodes (and I think they need to be in the same network as well). When an atom is connected to more nodes, these will be ignored.

So, the question is if you really need to use 2 different networks. If so, you would have to make a 'connection' in between using for example to queues or warehouses connected to each other in stead of 1 drop off warehouse at the beginning of the lane. 1 is connected to network 2 and the APM drops the product there. Then the product "jumps" into the next warehouse which is connected to network 1 and the combi picks up the product there. To take the right capacity into account, you could control the two warehouses by using the closeinput and openinput commands.

I changed your model a bit, see attachment (used 1 network). Just post again when something isn't clear.

Regards, Marlies
Attachments
06-25.mod
(62.3 KiB) Downloaded 361 times
Katinka
Posts: 23
Joined: Thursday 14 June, 2012 - 08:42

Re: Warehouse atom

Post by Katinka »

Hi Marlies,

Thanks for your answer. In the warehouse I'm simulating, the Combi trucks are only allowed to switch aisles at the back end (hence the left side of the long storage racks), because else they would block the travelling of the APM trucks. That is why I created two networks. In the example you've attached the Combi trucks also switch aisles at the front end, i.e. the right side, because (logically) that's a shorter distance to cover.
However, I applied your idea about creating an extra drop off warehouse and that's working perfectly!

I have a new question though. The aisle-switching of the Combi trucks is time-consuming and takes a fixed 120 seconds. I tried to represent this by changing the turn speed and/or corner speed of the Advanced Transporter (the aisle-switching might be seen as a turn of 180 degrees?), but nothing seems to change? I changed them to ridiciously low values, but the Combi truck is still fast and smoothly travelling.

Katinka
marlies
Posts: 301
Joined: Monday 17 January, 2011 - 09:28

Re: Warehouse atom

Post by marlies »

Hi Katinka,

I had the same problem recently. At the time I found out that there is a bug in the Network Controller atom. The angles were not calculated correctly.

Find attached an updated version of the file Network Controller.atm. The file needs to be in the following folder:
C:\Program Files\Enterprise Dynamics\Atoms\ (folder names can be slightly different on your pc).

With this updated atom you should see deceleration and acceleration when using corners and corner speed.

Regards, Marlies
Attachments
Network Controller.atm
(22.13 KiB) Downloaded 363 times
Katinka
Posts: 23
Joined: Thursday 14 June, 2012 - 08:42

Re: Warehouse atom

Post by Katinka »

Hi Marlies,

I tried all sorts of things, but it still doesn't work. However, I don't know if it has something to do with the Windows version I'm running (Windows Vista) or that I'm doing something wrong.

First I deleted the old 'Network Controller.atm' file and then pasted the new file into the folder. Then I got the message:

" 1 Time: 0 Atom: ED Logistics (ID=3), OnInit>4DScript:error at "ExecFile":Can not open file C:\Program Files\Enterprise Dynamics 8 Developer\Atoms\Network Controller.atm "

Hence, I restored the old 'Network Controller.atm' file. Now, instead of deleting it, I replaced it with the new .atm file. This time I didn't get the message above, but nothing seems to change in the model when I change parameters. I used the model you placed a few posts ago and changed the corner speed and turn speed to 0.01. However, nothing changes..

Katinka
User avatar
MatthijsJongboer
Posts: 200
Joined: Thursday 11 November, 2010 - 14:12

Re: Warehouse atom

Post by MatthijsJongboer »

Hello Katinka,
It could be that when you use Windows Vista or Windows 7, the Virtual Store is the problem here.
Have a look at the following location (similar to where you installed ED) to see if the file is also there:

Code: Select all

C:\Users\useraccount\AppData\Local\VirtualStore\Program Files\...
When it is there, it's best to delete this file and try it again.
Katinka
Posts: 23
Joined: Thursday 14 June, 2012 - 08:42

Re: Warehouse atom

Post by Katinka »

Hello Matthijs,

Thanks for your answer. The file was indeed in the Virtual Store. I deleted it and it works better now! :)
However, not the way I would like it, but perhaps I'm misunderstanding the exact function of the turn and corner speed parameters.

In my model, switching of aisles takes 120 seconds. It could be seen as a turn of 180 degrees (two times 90 degrees). That's why I added in the network two angles of 90 degrees and put the turn parameter at 180/120=1.5 degree/second. But still the Advanced Transporter needs only a few seconds to make the turn of 90 (180) degrees. I experimented with the corner speeds as well, and yes, the Advanced Transporters slow down at corners, but not enough.. It still takes them just a few seconds to make a turn.
marlies
Posts: 301
Joined: Monday 17 January, 2011 - 09:28

Re: Warehouse atom

Post by marlies »

Hi Katinka,

I had a better look at all the settings:
- The turn speed is influencing the turn speed of the transporter icon, it doesn't influence transportation time.
- The corner speed settings influence the speed that transporters will have in the corner and influence the transportation time. But, it will still be difficult to find the right settings to get the 120s aisle transfer time in all situations.

But, the network nodes have an option to limit the speed on a certain network path. I think that this will give you the best results. In the attached model I limited the transport speed at the back end to 0.05 m/s (the distance is 6m) and as a result the travel time takes about 120s.

You can set this setting by right clicking a node. Then select "Edit capacity and speed limit". The speed limit can be defined per direction. Set 1 in the 3rd column to use the speed limit and the speed itself in the 4th column.

Hope this helps.

Regards, Marlies
Attachments
06-25.mod
(62.5 KiB) Downloaded 364 times
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