Figure4

Figure 4. An illustrative run of the source searching process using a multi-robot system. (A-C) Trajectories of the four robots and the estimated source locations at steps $$ k=1 $$, $$ k=5 $$, and $$ k=18 $$, respectively; (D) the PSO iteration and global fitness; (E) the observables of agents during the search. PSO: Particle swarm optimization.