A Bat Algorithm with Mutation for UCAV Path Planning

Algorithm 4

Algorithm of BAM for UCAV path planning.

Begin

 Step 1: Initialization. Set the generation counter 𝑡=1; Initialize the population of NP bats

   𝑃 randomly and each bat corresponding to a potential solution to the given

   problem; define pulse frequency 𝑄; set loudness 𝐴_𝑖, the initial velocities 𝑣_𝑖 and

   pulse rate 𝑟_𝑖(𝑖=1,2,…,𝑁𝑃); set weighting factor 𝐹.

 Step 2: Generating rotation coordinate system. Transform the original coordinate

   system into new rotation coordinate whose horizontal axis is the connection

   line from starting point to target point according to (1);

   convert battlefield threat information to the rotation coordinate system and

   divide the axis 𝑋^′ into 𝐷 equal partitions. Each feasible solution, denoted

   by P ={𝑝₁,𝑝₂,…,𝑝_𝐷}, is an array indicated by the composition of 𝐷

   coordinates which are the floating-point numbers

 Step 3: Evaluate the threat cost J for each bat in P by (4)

 Step 4: while The halting criteria is not satisfied or 𝑡 < MaxGeneration do

      Sort the population of bats P from best to worst by order of threat cost 𝐽

      for each bat;

      for  𝑖=1 : NP (all bats) do

          Select uniform randomly 𝑟₁≠𝑟₂≠𝑟₃≠𝑖

          𝑟₄=⌈𝑁𝑃∗rand⌉

          𝑣^𝑡_𝑖=𝑣_𝑖^𝑡−1+(𝑣^𝑡_𝑖−𝑥_∗)×𝑄

          𝑥^𝑡_𝑖=𝑥_𝑖^𝑡−1+𝑣^𝑡_𝑖

          if (rand > 𝑟) then

            𝑥^𝑡_𝑢=𝑥_∗+𝛼𝜀^𝑡

          else

            𝑥^𝑡_𝑢=𝑥^𝑡_𝑟1+𝐹(𝑥^𝑡_𝑟2−𝑥^𝑡_𝑟3)

          end if

          Evaluate the fitness for the offsprings 𝑥^𝑡_𝑢, 𝑥^𝑡_𝑖, 𝑥^𝑡_𝑟4

          Select the offspring 𝑥^𝑡_𝑘 with the best fitness among the offsprings

            𝑥^𝑡_𝑢, 𝑥^𝑡_𝑖, 𝑥^𝑡_𝑟4

          if (rand < 𝐴) then

            𝑥^𝑡_𝑟4=𝑥^𝑡_𝑘;

          end if

        end for  𝑖

     Evaluate the threat cost for each bat in 𝑃 by (4).

     Sort the population of bats 𝑃 from best to worst by order of threat cost 𝐽

     for each bat;

     𝑡=𝑡+1;

 Step 5: end while

 Step 6: Inversely transform the coordinates in final optimal path into the original

   coordinate, and output

End.