topic TE Collision Problem in FlexSim Forum

TE Collision Problem

962076751 — Wed, 21 Aug 2019 09:45:48 GMT

[ FlexSim 19.1.0 ]

Hi ! As you can see in model 001001.fsm and model 002002.fsm, when i set up collision logic for every TE, error happens. While no error happens if only TE2's collision logic is set. But in a large scale TE system, collision detection happens on every TE. How to set up collision logic for every TE correctly to avoiding this situation? Your suggestion will be appreciated.

Best Regards!

Re: TE Collision Problem

joseph_g3 — Wed, 21 Aug 2019 21:23:14 GMT

@meng L

The reason for the problem you are seeing in model 001 is that when the Task Executors come into contact with each other, both of their "Handle Collision" triggers are fired, causing them both to stop. This leads to repeated starting and stopping that blocks either Task Executor from being able to move. I suggest setting up your TE system so that Task Executors only stop for the Task Executor in front of them.

One way to do this is to make Task Executors only stop during collisions with a specific car. In the example model I've attached, Task Executor 1, 2, and 3 are in order along the network nodes, so TE 2 will only have to stop for TE 1, TE 3 will have to stop for TE 2, etc.

Here is some of the code I used to do this (For TE 3):

Object otherobject = param(1);
Object thisobject = current;
if(otherobject == Model.find("TaskExecuter2")){
	thisobject.stop(48);
	senddelayedmessage(thisobject,0.5,thisobject);
}

Here is the example model: tecollisionanswer.fsm

Re: TE Collision Problem

962076751 — Thu, 22 Aug 2019 01:06:53 GMT

Hi Joseph!Thanks for your reply.I get your idea.But as we know, the models attached here are simplified. Under most circumstance, routes are more complicated. It is unknown that which TE may come into a collision with current TE. In other words, we need figure out which TE is in front position in a collision.

Re: TE Collision Problem

joerg_vogel_HsH — Thu, 22 Aug 2019 07:38:48 GMT

@meng L, wouldn’t your last comment be a good new question? “How to identify the previous traveler on network node path segment?”. Regards Jörg!

Re: TE Collision Problem

962076751 — Thu, 22 Aug 2019 08:30:49 GMT

Yes Jörg, you are right.Essentially this is what i realy want to express in this question. I post it as a new question here.

https://answers.flexsim.com/questions/71183/how-to-identify-the-front-traveller-during-a-colli.html