Multiobjective Optimization Based Vessel Collision Avoidance Strategy Optimization

Algorithm 1

(1) Pop  =  InitPop(𝑁)

(2) InitRank()

(3) Pop1  =  select(Pop)

(4) Popt  =  crossover(Pop)

(5) Pop2  =  mutation(Popt)

(6) while terminal_condition

(7)    Pop(𝑛)  =  Pop1(𝑛) ∪  Pop2(𝑛)

(8)    for 𝑝 in Pop(𝑛):

(9)       𝑝𝑑𝑜𝑚𝑞=[]

(10)        np  =  0

(11)        for 𝑞 in Pop(𝑛)

(12)          if 𝑝 dominate 𝑞

(13)            pdomq.add(𝑞)

(14)          else if 𝑝 is dominated by 𝑞

(15)             np  =  np  +  1

(16)          if np is the first rank of Pareto

(17)          p_rank  =  1

(18)      F1.add(𝑝)

(19)    F.add(F1)

(20)    while 𝐹[𝑖]

(21)       for 𝑝 in 𝐹[𝑖]

(22)        for 𝑞 in pdomq

(23)          if nq is dominated by other individual

(24)                q_rank  =   𝑖+1

(25)                Q.add(𝑞)

(26)       F.add(𝑄)

(27)       𝑖=𝑖+1

(28)    Pop(𝑛+1) = []

(29)    while len(Pop(𝑛+1) + len(𝐹[𝑖]) < 𝑁

(30)      nLen = len(𝐹[𝑖])

(31)       for 𝑖 in 𝐹[𝑖]

(32)         init 𝑖.distance  =  0

(33)       for objFun in M objective function

(34)         𝐹[𝑖]  =  sort(𝐹[𝑖], objFun)

(35)         for 𝑖 in xrange(1, 𝑙𝑒𝑛(𝐼)−2):

(37)        𝐹[𝑖] [𝑖].distance  =   𝐹[𝑖][𝑖].distance  +   (𝑜𝑏𝑗𝐹𝑢𝑛(𝐹[𝑖][𝑖+1]−𝑜𝑏𝑗𝐹𝑢𝑛(𝐹[𝑖][𝑖−1])))(𝑀𝑎𝑥(𝑜𝑏𝑗𝐹𝑢𝑛())−𝑀𝑖𝑛(𝑜𝑏𝑗𝐹𝑢𝑛()))

(38)       Pop1(𝑛+1) = [Pop(𝑛+1); 𝐹[𝑖]]

(39)      Pop2(𝑛+1)  =  generate new pop

(40)       𝑖+=𝑖+1

      𝑛=𝑛+1