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Roan DJ2 avatar image
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Roan DJ2 asked Joerg Vogel answered

Crane issue

Dear all,

I am busy with a Flexsim model for a specific terminal at this moment. The model is about loading and unloading trains on a terminal. The model in the attachment is about loading a train from the stack. In this situation I need to visualize waiting times and driving times of tug masters at the automated stacking cranes.

To simulate this I made an model with three cranes and one transporter. The crane only starts moving to pick up a container if the tug master arrives at the stack. The driver has a computer in his tug master which he uses to send an confirmation to the stacking crane.

Could some one explain me how a crane starts moving if the transporter arrives at the stack?

Kind regards,

Roan de Jong

laden-trein-3.fsm

FlexSim 18.0.3
transportercrane movementterminaltugtugmaster
laden-trein-3.fsm (35.7 KiB)
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Joerg Vogel avatar image Joerg Vogel commented ·

The direct transfer is possible from one task executer to another. In my opinion you should try to insert queues between the direct action. It is much easier to implement the transport of items from a queue by a crane.

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Roan DJ2 avatar image Roan DJ2 Joerg Vogel commented ·

What do you mean with 'insert queues between the direct action'?

I already use transport from queue to queue by a crane if you ask me.

Isn't there a function or something that the crane starts moving to the (stack)queue if the transporter arrives at the (unloading)queue? At this moment the crane is constantly moving and it does not check whether the transporter arrived at the queue near the crane.

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1 Answer

Joerg Vogel avatar image
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Joerg Vogel answered

My fault, I didn't look in the model before I wrote the comment. I expected a different model from the description. I have opened the model now. The queue calls a crane when the item can leave the queue. You control that if you close the output of the queue containing the item or closing the input of the queue receiving the item.

But you must create activities that forces the transporter to react earlier than the standard material flow would manage. When an item enters the Queue5 the output and the input of the queue is closed and a new created tasksequence calls the transporter to the Queue6. The same tasksequence sends a message to the Queue5. This sendmessage task is executed after the arrival at the Queue6. The OnMessage Trigger of the Queue5 opens the output. When the item is leaving the Queue5 by the crane, the input is opened again.

Further problems are the management of the parallel crane activities, because they can call the transporter to their queues, too. You prevent this, if the queues calling the transporter can not receive items.

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