topic Re: AGV pick up finished item when pass by processor in FlexSim Forum

AGV pick up finished item when pass by processor

kkkk — Mon, 14 Aug 2023 02:31:27 GMT

[ FlexSim 23.1.0 ]

Hi~ this is my current model: test.fsm

I set the random to select processor in the list:

Therefore, the AGV will sent item to processors in a random order.

Currently from my process flow settings, after my AGV sent the item to a random processor it will check if there is already a finished item, if there is a finished item the AGV will take the item to the sink immediately.

I will like to change the logic to every time the AGV pass by a processor it will check if the processor have a finished item, and take the item if the AGV's current loading item is less than 5. Hope to get some suggestions to revise my process flow to implement these settings, thanks!!!

Re: AGV pick up finished item when pass by processor

jason_lightfoot_adsk — Mon, 14 Aug 2023 11:41:30 GMT

I think this is a repost of the previous model where you had left exceptions in your model and then cleaned them up afterwards. Your GroupN list expression needs to account for groupName not existing when you push the item to the list by adding '?' to value.groupName.

Re: AGV pick up finished item when pass by processor

jason_lightfoot_adsk — Mon, 14 Aug 2023 11:54:33 GMT

What you're describing is similar to the way the AGV templates function, where the AGV travels between LookForWork control points at which it checks for items to load if it has capacity (using an item list partitioned by control points)

However you seem to be wanting to just look for work, not based on a fixed route but just when you're passing any control point. You could detect the pre-arrival at a control point the AGV is about to pass and preempt the current travel task with a travel/load task as needed. It would probably still be a good idea to push a list of items partitioned by control points rather than scan the connected stations for every prearrival event.

Re: AGV pick up finished item when pass by processor

kkkk — Tue, 15 Aug 2023 12:55:31 GMT

my new model: test_v2.fsm

Thank you so much~ I fixed my process flow in order to achieve my settings I mentioned above, and my logic is below.

on the left side of split: let the AGV move to the random processor and it will drop off the item which was picked up from source.

on the right side of split: let the AGV move to every processor and check if there are items to take to sink.

The AGV currently is not moving correctly, it will

move to processor1 to check if there is item to take to sink go to processor3 to drop item
go to processor3 to drop item
move to processor2 to check if there is item to take to sink
move to processor3 to check if there is item to take to sink

The order should be step1, 3, 4, 2 to make more sense. I wonder how to revise my process flow settings to let two sides of split work the way I mentioned, thanks!!!

Re: AGV pick up finished item when pass by processor

jason_lightfoot_adsk — Tue, 15 Aug 2023 13:48:06 GMT

I think you need to do some tutorials to understand how process flows, task executers and AGVs work. Use your academic institution's course notes or the online tutorials.

You have two travel tasks after the split which will both issue a job to the AGV at the same time. The sequence by which it undertakes them is probably based on the connection rank which is not ideal - with the other task getting queued until the parallel task is complete. Step through the model and look at the tokens and consider if what you have is correct.

Also you still have exceptions at the decision point 'if AGV has item'.

We strongly encourage students to research, experiment and test, and are happy to offer guidance when they get stuck.

Re: AGV pick up finished item when pass by processor

kkkk — Thu, 17 Aug 2023 14:02:29 GMT

Hi~ I already fixed my model: test_v3.fsm

For now, I used these variables to represent different status (for example if p1 == 1 it means AGV has went to processor1 to take finished item back)

it will run according to my settings as I mentioned above except when AGV sent the item to a random processor and the same processor also have item to take to sink. I have no idea why the AGV will pick up the item at source (the item which should be taken from the processor's unloading port will just disappear) instead of pick up at the processor's unloading port (this situation only happens when the processor the AGV sent item from source also has item to pick up and sent to sink) .

Hope to get some suggestions, thanks in advance!

Re: AGV pick up finished item when pass by processor

jason_lightfoot_adsk — Thu, 17 Aug 2023 14:52:00 GMT

Your model upload was not successful - please try again. Also, you can help us find your next point of concern quickly by telling us the event time and objects with which it occurs.

Re: AGV pick up finished item when pass by processor

kkkk — Thu, 17 Aug 2023 16:42:06 GMT

I've reuploaded my model! And the event time is from about 190-220 , thanks!

Re: AGV pick up finished item when pass by processor

jason_lightfoot_adsk — Thu, 17 Aug 2023 18:22:33 GMT

Looks like it was a bad activity connection. I added some delays (zero time) so that you can more easily step through the model to check what's happening (and tidied up the process flow layout).

test-v3_jl.fsm

Re: AGV pick up finished item when pass by processor

kkkk — Thu, 17 Aug 2023 18:33:15 GMT

Thank you very much! It looks more neat now!

However, after I run the model you provided, the AGV will be stuck at the time of 185 and doesn't move anymore, not sure what cause this situation

Re: AGV pick up finished item when pass by processor

jason_lightfoot_adsk — Thu, 17 Aug 2023 18:38:28 GMT

It's got a stop time so that you can run fast to that point, slow it down and run again, or press step to see the token move through the activities.

Re: AGV pick up finished item when pass by processor

kkkk — Thu, 17 Aug 2023 18:41:27 GMT

But I've already turn the run speed to maximum and it was still stuck at that point~

Re: AGV pick up finished item when pass by processor

jason_lightfoot_adsk — Thu, 17 Aug 2023 20:06:38 GMT

Remove the stop time or press run again (without reset) when it reaches that time.

Re: AGV pick up finished item when pass by processor

kkkk — Fri, 18 Aug 2023 05:34:44 GMT

@Jason Lightfoot After I press the run it works! Can I ask why it will stop at that point and have to press run to let the AGV move again?

By the way, I discovered that around time 300-340, the problem I mentioned will occur again but this time is among different processors, is it because of the delay activity?

Re: AGV pick up finished item when pass by processor

jason_lightfoot_adsk — Fri, 18 Aug 2023 06:46:03 GMT

As I said above:

It stops at that time because I told it to:

Why did I tell it to? So that I can fast run to the point of interest and then step through the process to see what's happening.

How do you step through the process? You press the Step button in the run control panel.

It's happening again, why? Check your model connections by stepping through and see where the token is skipping travel tasks and going directly to the load task.

Is it because of the delays? No.

We take the time to try and help you with the specifics of your model, so we ask you to take the time as a student to read the answers given and where something is new/unknown to you, try to find it in your course notes or the online documentation, rather than repeat the same question back to us.

Re: AGV pick up finished item when pass by processor

jason_lightfoot_adsk — Wed, 23 Aug 2023 12:35:37 GMT

Hi @kkkk, was our answer helpful? If so, please click the "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 comment back to reopen your question.