question

So the basic Crane logic for collision was really written to be more of a template really. If you have specific logic that you need your cranes to follow, you'll have to figure out what you need and write the logic yourself. I believe the two cranes are getting hung up in the later half of the Crane collision code. If you'll look there you'll see that there is some fairly complex layers of checks involving preemption and priority.

This happens because technically, if the two cranes had the exact same priority your model would be deadlocked. Crane 2 is trying to get to the pickup and Crane 1 is trying to get to the other side, so they'd be stuck. So the basic FlexSim crane collision script wrote that last half of the code, to try and guess what priority you want the cranes to have, and to preempt their current tasks, or the previously incurred task from before, to try and best capture that.

I'm not 100% certain, but I'm willing to bet the cross over of the cranes has to do with getting muddled up in this preemption logic portion of the code, that and potentially the timing interval of how often it's checking for collision. IE if your preemption suggests that it's the other guy's turn to get out of the way, and then you don't check collisions until after the fact that the cranes have crossed, then it's going to act as if the left crane was on the right and the right crane was on the left, and further push them away, once that collision actually fires.

I'm not sure I have a solid answer on what to do. (Because I don't know what you need for you model.) But I would play around with the collision timing, as well as look into either modifying or writing your own logic for that preemption half of the crane logic. You may want it so Crane 2 always gives in and gives priority to Crane 1, or you may want the loaded crane to have priority. You'll have to write logic for that to determine that.