Claim two-way AGV path for one direction

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Mischa Spelt asked Mar 27, '17 anon-user commented May 21, '21

Claim two-way AGV path for one direction

We ran into a situation that should be fairly common so I hope that someone has a solution floating around that we can easily implement or re-use.

The model consists of two areas joined by a narrow corridor. The corridor is only wide enough for a single AGV path. AGVs need to move in both directions (left-to-right and right-to-left) through the corridor. All AGVs going in a single direction can follow one another based on the default accumulation rule, but AGVs going in the opposite direction have to wait at the entry point until the corridor is clear.

I have attached a small demo model to illustrate the situation. If you run it, then as expected the AGVs collide:

time: 58.794802 exception: TaskExecuter4 has run into TaskExecuter2 on an accumulating path. This is not allowed.

We would appreciate any ideas on the simplest way to implement this. In reality we use Process Flow to control the travelling, so this model may be slightly more realistic.

Software Version:

FlexSim 17.0.3

agv path control points

agv-corridor.fsm (26.5 KiB)

agv-corridor-pf.fsm (34.6 KiB)

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anon-user commented · May 21, 2021 at 01:32 PM

Please tell us about the model tree for this simulation.

agv: AGVNetwork>variables/agvs/TaskExecuter4

In this tree, "agvExitDist: 1.797693e+308" is displayed.

What does this number mean?

Why are these numbers so big?

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Answer 1 · 2017-04-03T12:25:11Z

Mischa Spelt answered Apr 3, '17 anon-user commented May 21, '21

Last week I put together a bit of Process Flow to claim the area in one direction. I used a Control Area to represent the restricted area, but it doesn't really control anything: it acts as a visual indicator to indicate the boundaries of the area, and it is used as a container allowing the control points (connected by center connection) to share data through the Control Area's labels.

I did have to work around one small issue: neither Control Areas nor Control Points have an On Message trigger, so I'm actually stuffing a FlexSimObject into a label so I can signal the Area at some point.

agv-corridor.fsm

agv-corridor.fsm (100.3 KiB)

Answer 2 · 2017-03-30T15:02:00Z

Sam Stubbs answered Mar 30, '17 Mischa Spelt commented Apr 3, '17

I'm not sure this is exactly the set up you're looking for, but in order to control the two way corridor area, you'll need to have more control points to reserve and allow allocations. Here's an example that keeps the AGVs from colliding from each other.

5965-agv-corridor.fsm

5965-agv-corridor.fsm (27.9 KiB)

· 2

jing.c commented · Mar 31, 2017 at 01:18 AM

Hi, Sam.

Your model seems simple and effective!

Is it a simple way to allow more agvs enter two-way corridor area with the same direct?

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Mischa Spelt commented · Apr 03, 2017 at 12:37 PM

Nice and clean solution! Unfortunately it does not entirely fit our needs because we'd like to admit multiple AGVs going the same way. I assume that the control point is allocated first-come-first-serve, hence always sending AGVs through in alternating directions (because the second AGV always has some travel time to the waiting point and in the mean time the AGV from the opposite direction already waiting will claim the central point)?

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