question

Hi @Shaun G,

Some of this logic is going to be very complicated, so I will provide a high level overview and attach a sample model.

1) Since this logic is more complicated, we are going to push all three operators onto a list to be pulled. You can read more about lists here:

1. https://docs.flexsim.com/en/20.1/Reference/ProcessFlowObjects/SharedAssets/List/

2) Since the number of racks being carried by the AGV varies, we will need custom code to control this logic. In the process flow box called "Load Items on AGV Racks", a token is created as the AGV arrives at CP4. The token then requests 3 operators. A subflow is then run creating 1 token for each operator. The custom code is as follows:

for (int i = 1; i <= token.AGV.subnodes.length; i++)
{
    if (token.AGV.subnodes[i].subnodes.length <= 10)
    {
        return token.AGV.subnodes[i];
    }
}

return 0;

This will return 0 if all racks are full, and return the rack if it is not. The tokens will then pull from the RackItem list, travel to the Item, pick it up and place it in the AGV rack. Here are links to the documentation:

1. https://docs.flexsim.com/en/20.1/Tutorials/ProcessFlow/Tutorial1UsingSharedAssets/1-1UseListResource/
2. https://docs.flexsim.com/en/20.1/Reference/ProcessFlowObjects/SubFlow/RunSubFlow/

3) Note that the AGV module was not really designed for the behavior you are looking for. It is very difficult, if not impossible to get the AGV to stop, wait for an event, then start up again. This is because of the task sequence principle of FlexSim (see link below).

However, I managed to create a small work around in the Process Flow box "Stop AGV if not Full". This creates a token at CP6, then computes if there is any space left for items on the racks. If there is, then it will preempt a task sequence on the AGV to have it delay a time of 20 seconds * number of racks.

1. https://docs.flexsim.com/en/20.1/ModelLogic/AdditionalConcepts/Preemption/
2. https://docs.flexsim.com/en/20.1/Reference/TaskSequences/TaskSequenceConcepts/

I hope this helps!

26910-load-while-moving-v2 (2).fsm