crash when using collision avoidance, motion commanded using goTo()

[boomer319]

I had drones crash into each other. Using goTo() to send all of them to one point.

Is this the proper way of enabling collision avoidance in crazyflies.yaml (colAv as in collision_avoidance.c)?

crazyflies.yaml:

firmware_params:
    commander:
      enHighLevel: 1
    stabilizer:
      estimator: 2 # 1: complementary, 2: kalman
      controller: 1 # 1: PID, 2: mellinger
    colAv:
      enable: 1

If thats the case: What is goTo() doing to interfere with onboard collision avoidance?

[whoenig]

This should work. Here is a test script we successfully used (swapping task of 2 UAVs):

#!/usr/bin/python3
import numpy as np
from crazyflie_py import *
import subprocess 
import shutil
import os

def main():
    swarm = Crazyswarm()
    timeHelper = swarm.timeHelper
    allcfs = swarm.allcfs

    allcfs.setParam("colAv.enable", 1)

    allcfs.setParam("colAv.ellipsoidX", 0.15)
    allcfs.setParam("colAv.ellipsoidY", 0.15)
    allcfs.setParam("colAv.ellipsoidZ", 0.3)

    # for the flight part
    allcfs.takeoff(targetHeight=0.5, duration=3.0)
    timeHelper.sleep(3.0)

    # go to initial positions
    for cf in allcfs.crazyflies:
        pos = np.array(cf.initialPosition) + np.array([0, 0, 0.5])
        cf.goTo(pos, 0, 3.0)
    timeHelper.sleep(3.0)

    # swap positions
    cf1 = allcfs.crazyflies[0]
    cf2 = allcfs.crazyflies[1]

    pos1 = np.array(cf2.initialPosition) + np.array([0, 0, 0.5])
    cf1.goTo(pos1, 0, 5.0)

    pos2 = np.array(cf1.initialPosition) + np.array([0, 0, 0.5])
    cf2.goTo(pos2, 0, 5.0)

    timeHelper.sleep(5.0)

   # swap positions (again)
    cf1 = allcfs.crazyflies[0]
    cf2 = allcfs.crazyflies[1]

    pos1 = np.array(cf1.initialPosition) + np.array([0, 0, 0.5])
    cf1.goTo(pos1, 0, 5.0)

    pos2 = np.array(cf2.initialPosition) + np.array([0, 0, 0.5])
    cf2.goTo(pos2, 0, 5.0)

    timeHelper.sleep(5.0)

    allcfs.land(targetHeight=0.02, duration=3.0)
    timeHelper.sleep(3.0)

if __name__ == "__main__":
    main()

The underlying BVC algorithm is sensitive to hyperparameters. These parameters unfortunately also depend to some extend on the number of drones. Thus, you might need to re-tune.

[boomer319]

Thank you! I appreciate the quick response time.