“…Most methods for this subprocedure are biologically inspired, such as the gradient-following algorithms [11,12,13,14], the zigzagging algorithms [2,13], the upwind algorithms [8,15], adapted ant colony optimization algorithm [16], particle swarm optimization algorithm and its variants [17,18,19,20], the SPIRAL algorithm [21], and genetic programming algorithm [22]. During the plume tracing procedure, how to re-contact a lost plume is also an important issue [23]. In the final phase, the robot locates the source [24,25].…”