How to [partially] fix formation maneuvers (copied from feedback thread)

[neph]

Currently, ships' movement screams poorly tuned PID to me. The effect is worsened when ships are following one another--perturbations in the lead vessel(s) course amplify oscillations in the following vessels'.

 

It's common to see behavior like this when commanding a turn in a line of vessels.

 

It seems like this behavior is due to following ships trying to maintain a constant distance from their lead ships. It means that the second ship will begin to turn late, since the distance opens up only when the lead ship is in the maximum of its turn, and then because of ship handling characteristic the second ship will not be in the maximum of its turn until after the lead ship has settled into its new course.

This causes a yet further delay for the course change of third & later following ships, meaning that the effect is exacerbated going down the line. It leads to a whip-lash effect and the third and later ships usually greatly overshoot, fall out of formation, and have to complete a long and slow 360° turn to return eventually to formation. It's almost impossible to keep ships in lines longer than 2, even through very very simple maneuvers. 

 

I propose than instead of each ship only looking at the distance from the one before it, an iterative process that amplifies perturbations and quickly leads to bad behavior in high-inertia/slowly-handling ships, we try a different method.

Have behind the lead ship a "ghost division" of calculated ship positions--where ships should be if they followed perfectly (had perfect handling & no delay). Each ship instead will simply try to minimize their distance to the corresponding element of the ghost division.

This should minimize whip-lash and keep ships in formation through simple turns.

Thishttps://imgur.com/j4DueZB