Questions about Downwash

[yuchen-x]

Hi,

I am not a low-level control guy, according to my understanding, the _downwash() in BaseAviary.py is for automatically avoiding potential collisions with other drones.

But, it seems only working for the drones flying at different height. For example, if I set the initial z=1 for both two drones in your examples/downwash.py, the two drones will collide or one of the drone suddenly going somewhere.

I was wondering:

1. Is it possible to achieve the downwash when the drones flying at same height, and how?
2. How to set the downwash distance?
3. I modified the downwash.py to be with 3 drones (with initial z = [0.99, 0.999, 1.0] in the following video, I didn't get how the mechanism decides which drone to downwash, could you explain it to me? It seems not always the lower one to perform downwash, right?
   

Thank you!

[JacopoPan]

Hi @yuchen-x,

I think you misunderstood the intent of _downwash(). It is not a potential-based collision avoidance approach.
It is a physical phenomenon leading to reduced lift in the turbulent air generated by 2 drones crossing paths at different heights.

If you are interest in creating a repulsive force field around a drone, you could still exploit PyBullet's applyExternalForce() method and the information about the drones' relative distances. However, it wound't be very realistic nor within the scope of this simulation (for quadcopters).

[yuchen-x]

I see，thank you very much for the quick reply and the explanation!