How to let Elevator connected conveyors work bidirectional without collision?

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shanice.c asked Aug 1, '21 shanice.c edited Aug 16, '21

How to let Elevator connected conveyors work bidirectional without collision?

I want to let a multi-floor model that there are two elevators sending Box1 and Box2 between these 2 floors. Both elevators can be used to load from 1F&2F and send boxes to 1F/2F floor. So how can I control at conveyor to avoid any boxes collision(ex: a box is sent from 1F to 2F, but another box in 2F heading to 1F directly enter conveyor without looking into if there's other box coming, so these two boxes might bump each other.) For the bidirectional parts of conveyor(The green background part of the conveyor), now I use two physical conveyors, and hope there's method to control boxes flow from crash. I hope to overlap these two different direction conveyors and hide the physical away. but I'm afraid that one conveyor(The yellow background part of the conveyor) is not allow to connected to two conveyors, and still cause error. Is there an easier way to complete what I want to do?

Our conveyor layout design is like the picture, the conveyors in front of elevator are bidirectional, elevators are also bidirectional, the horizontal conveyor between two bidirectional conveyors is limited to transfer box to the right hand side.

After completing the actions of letting boxes transported by elevators and conveyor in bidirectional works correct. Then I'd like to hide all conveyors, and replace conveyor appearances with our custom 3D conveyor shape. It has been a big problem that I cannot find the setting to show them again after hiding conveyor objects. It's not like other objects(ex: queue, processor...) that I can show 3D again by clicking Visuals-More visuals-Show 3D shape. I tried to find conveyors at Tree, but there's no option to find the setting to show 3D shape again.

Elevator.fsm

Software Version:

FlexSim 21.1.4

conveyor flexsim 21.1.4 3d shape elelvator mutifloor

1627799697374.png (43.6 KiB)

elevator.fsm (53.0 KiB)

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David Seo commented · Aug 02, 2021 at 12:36 AM

@Fiona C

You should solve TWO issues.

The first is to make the conveyor reversible.

The second is not to bump the items.

You can control your issue before the item entering to the yellow conveyor in both floors.

The bidirectional conveyor can be set by setting the speed to minus. It can't be set to use TWO conveyors in one postion. If you want to use TWO conveyors, you should use them separated and then control the items to be entered or not to be entered. it's control is not easy comparing to using ONE reversible conveyor.

https://answers.flexsim.com/questions/55089/the-capability-to-reverse-conveyors-in-2018-update.html?childToView=55131#answer-55131

This link is for the reversible conveyor.

And the way not to bump the items is...

To use "Area Restriction" option menu in Decision Point of the conveyor 'On Arrival' trigger.

You can find also the examples about area restriction feature in this forum site.

https://answers.flexsim.com/questions/22455/can-i-have-multiple-decision-points-share-informat.html

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shanice.c David Seo commented · Aug 02, 2021 at 09:44 AM

Hello @David Seo. Thank you for your answer. I would like to use a simple way to do this. I try to solve the issues you mentioned above for 1st floor firstly. Could you help me with my example to explain for me please. I'm really unfamiliar with conveyor system. The demand of my company case is quite complicated for me. I read many examples and manual, but not really understand how conveyor system works and really need some supports.

In my model, I make box waiting before entering yellow conveyor for the first time, but I cannot release another 4 boxes after. I use on continue to release following boxes, but it doesn't work. Could you help me checked if my setting still works if 2F demand is also added to the model? I also need help with the problem that I need the elevator to load 2 boxes every time. I already set TaskExecuter capacity in to 2, and there is more than 1 box in the conveyor. I have no idea why it still load 1 at a time.

test control conveyor2.fsm

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test-control-conveyor2.fsm (56.8 KiB)

David Seo shanice.c commented · Aug 02, 2021 at 11:26 PM

@Fiona C

I uploaded a sample model to control no bump. I hope this sample to help your solving.

test-control-conveyor2_2.fsm

I would recommend you to use only 3D object trigger logic not using process flow when using the conveyors like your issue.

Because you should control the conveyor's in/out port and reversing move.

In addition to that, the elevator's moving the items up or down. All of them will be a very complicate control like the PLC logic. If you will use the conveyor decision points trigger and process flow at same time, the control of them all will be more difficult, I guess. It's my opinion with experiences.

I recommend to use only the 3d objects trigger logic or only the process flow logic.

If you use the mixed logic of two paradigm, it will be very complicate in your case.

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test-control-conveyor2-2.fsm (66.7 KiB)

Jeanette F ♦♦ commented · Aug 16, 2021 at 01:44 PM

Hi @Fiona C, was David Seo's answer helpful? If so, please click the red "Accept" button at the bottom of their answer. Or if you still have questions, add a comment and we'll continue the conversation.

If we haven't heard back from you within 3 business days we'll auto-accept an answer, but you can always unaccept and comment back to reopen your question.

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Answer 1 · 2021-08-07T14:07:16Z

shanice.c answered Aug 7, '21 David Seo commented Aug 7, '21

Hi, @David Seo, why in your example you use shape21 as Area Owner?

I think in my case the restricted area would start from entering the 4F yellow conveyor until the exiting from the 5F yellow conveyor, could a restricted area used in a crossing-floors case?

Also, could you explain more about why I should control conveyor's in/out port? And give me some examples which kind of Triggers to use? Do I still reverse conveyor by setting speed to negative, or any way to switch conveyor's start and end in X,Y? Thank you!

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David Seo commented · Aug 07, 2021 at 05:33 PM

@Fiona C You said the elev#1 and elev#2 should transfer bi-directionly the items?

The items can be moved to 2F from 1F and in other case from 2F to 1F via elev#1. It's the same in the elev#2, is it right?

If an item should be moved to 1F from 2F via elev#1 and then be moved to the point of 'sink box2' and another item which should be moved to 2F from 1F via elev#1 and then moved to the point of 'sink box1', how can you control it?

Before entering the cross conveyor, the item from 1F should be waiting for till the item from 2F out to 1F through elev#1 and then the item from 1F can be transfer to 2F through elev#1.

So you should use 'restricted area' option menu and same time you maybe use to control the conveyor's port to close and/or open before the cross-conveyor.

It's not easy to control the bi-direction conveyor anyway.

The reason of using 'shape21' is only for 'area owner'. Anything can be 'owner'. The area restriction usage is between from entering DP A to exiting DP B. The distance from A to be can be anything and any zone.

The DP and/or Station on the conveyor's cross-point can't be used for 'restriction area'. It can be applied only for one conveyor not two cross-conveyor.

The area restriction owner should be used for two DPs on conveyors.

The DP on the cross-point conveyor is applicable for only ONE conveyor not TWO conveyors. It looks like to be used in two conveyors but it can be used for one conveyor.

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