Bubble-net attacking

Bubble net attack is the bubble predation behavior of whales. The attack of the bubble net is divided into contraction encirclement and spiral update position mechanisms. In order to realize the contraction surround behavior, it is almost the same as the mathematical model of the prey behavior mentioned above. The difference is that the value of C changes from [−a, a] to [−1,1]. In the stage of spiral update position mechanism, the search agent approaches the target in a spiral shape. For the next iteration, probability selection will be used. If the probability is less than 0.5, the shrink-wrap mechanism is adopted. The probability is greater than 0.5, and the spiral update position is used.

where W* is the position vector of the best search agent, W(t) is the position vector of the search agent in iteration t, Z ' is the coefficient vector. b is a constant value. Random numbers are represented by k, and the range is [−1,1].