Comparing previous simulation work with current study. Comparing previous simulation work with current study. Sample timelines of two order parameters (right, velocity correlation at top and normalized velocity magnitude at bottom) from our previous work (40) (algorithm A) and our novel flocking model (algorithm B). Trajectories corresponding to the gray sections of the timelines are shown for both models on the left, with color mapped to time. Corresponding motion can be seen in movies S1 and S2. Algorithm B performs much better and has a lower transient time. We used the following interaction parameter set for algorithm A: Cfrict = 30 m2, m, m, and prep = 1 s−1 [for details on parameters, see (40)]. For algorithm B, we used the optimized parameter set for vflock = 4 m/s. Using an average from 10 simulations with the same parameter setup, the order parameters averaged over time were and m/s for algorithm A and and m/s for algorithm B. Gábor Vásárhelyi et al. Sci. Robotics 2018;3:eaat3536 Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works