Exception when resuming an AGV which was stopped during offset travel

Question

question

Allister Wilson asked May 26, '20 Bo.W commented Aug 4, '22

Exception when resuming an AGV which was stopped during offset travel

One of our customers added a MTBF/MTTR to their AGV model and found an issue with the new offset travel functionality.

It seems that stopping an AGV (with stopobject) at any point during an offset travel operation causes an exception to be thrown within resumeobject when you later try to resume it.

The attached model demonstrates this issue 14 seconds into the run.

For now I've got the customer's model running again by handling the offsets manually (as normal travel operations) in process flow, but I'd love a simpler workaround if you happen to find one.

20200526_agv_offset_with_stop.fsm

Software Version:

FlexSim 20.1.2

flexsim 20.1.2 agv network offset travel resumeobject

20200526-agv-offset-with-stop.fsm (31.1 KiB)

· 2

Allister Wilson commented · Jun 04, 2020 at 10:09 AM

Has anyone had a chance to look into this?

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tannerp commented · Jun 06, 2020 at 07:39 PM

@Allister Wilson I believe this might involve a bug. I'm not sure who is looking into it that could give you more information. I think the bug is related to this post, but I could be wrong.

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Answer 1 · 2020-09-30T14:55:35Z

Phil BoBo answered Sep 30, '20 Bo.W commented Aug 4, '22

Yeah, this looks like a bug. I'll add a case to the dev list.

We seem to have overlooked this question.

· 3

Bo.W commented · Aug 03, 2022 at 07:56 AM

Has the bug been fixed yet?

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Jason Lightfoot ♦ Bo.W commented · Aug 03, 2022 at 09:17 AM

Yes this is resolved in 22.0.6 and 22.2.0

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Bo.W Jason Lightfoot ♦ commented · Aug 04, 2022 at 08:12 AM

OK,Thanks.

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Answer 2 · 2020-09-30T09:32:34Z

gilbert jerald answered Sep 30, '20 Allister Wilson edited Sep 30, '20

@ allister.wilson You have used pickup point connection in you model that is not been referred anywhere that cause error in you model when AGV reach the pickup point. Normally the Pickup point connection are used when your model has more than one pickup point option. When you used the connection you should commend the AGV by process flow or by network properties to look for the available pickup point.

I have attached the modified model for your reference have a look at it

Support AGV.fsm

support-agv.fsm (31.2 KiB)

· 1

Allister Wilson commented · Sep 30, 2020 at 09:46 AM

Thank you for taking a look, unfortunately this just sidesteps the problem.

The pickup point connection is used within the On AGV Offset Travel trigger.
There is only one here for simplicity, but in a real model you'd have many pickup points (or some other connection type) to make use of the new AGV offset functionality.

In your model without the pickup point connection, no offset travel occurs, therefore the problem outlined in my question does not occur either.

For reference, having unused control point connections will not break your model.
As far as I know, connections other than Location (including the connection types added by default) have no inherent behaviour and will only have an effect if your logic (ex: the built-in AGV process flow template) uses them.

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