The phenomenon of people flying away due to social forces

[kim_j6]

[ FlexSim 23.2.2 ]

I'm making a model of evacuating to the exit at once in a crowded space.

But some people fly away. Why is that?

ex.fsm

[Jeanette_Fullmer]

Hello @Jerry,

Please resolve your exceptions first and repost your model.

[jason_lightfootVL7B4 · Accepted solution]

You don't have a proximity agent system defined so remove those activities from the two person flows 1F and 2F. Then you could try it in a supported version - in 23.2.2 the agents remain within the building.

ex_jl.fsm

[kim_j6]

I'm sorry. What exception are you talking about?

[kim_j6]

Thank you for your answer.

I'm trying to use the social force function for people's natural movements.

Is the issue also related to the proximity agent? Or did you answer that it was a version of the problem?

[jason_lightfootVL7B4]

The proximity agent activities were generating an exception since there was no such agent in your model.

Using a newer version of FlexSim seems to produce better results. Also note that even if there were a bug in 23.1 that branch is now closed and will receive no further updates. For any bug to be addressed it has to be reproducible in a current version.

Social force systems in FlexSim can seem somewhat chaotic since the parameters are not optimized for every application (I'm not sure for which application they are optimal as I've never seen any emergent people laning behavior). You may find you can improve your model by changing some parameters and/or increasing the frequency with which the forces are calculated, since it uses a tick based approach rather than solving a system of differential equations (as done in Dynamic Systems/Systems Dynamics models)

[jason_lightfootVL7B4]

Hi @Jerry, was Jason Lightfoot's 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.

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