Page 49 - Read Online

Page 16 of 27 Wang et al. Intell Robot 2023;3(4):538-64 I http://dx.doi.org/10.20517/ir.2023.30


parent( ), =



child( ) = parent( ), <
 (36)

parent( +1 ), ℎ


= 1, 2, ,
d. Shift: Select two different genes, and , by Equation (29), then shift the destination cell of the first
gene towards that of the second gene by one cell to adjust the location directionally.
{
( )
) ,
shift parent( ), parent( =
child( ) =
parent( ), ℎ (37)
= 1, 2, ,
where the shift function has the definition as follows:

(⌊ ⌋ ⌊ ⌋)
− 1 − 1
shift( , ) = + sgn (( − 1 mod ) − ( − 1 mod )) + · sgn − (38)

(iii) Mutation
Mutation is mainly used to attempt to access a new destination cell to increase the adequacy of access
to the solution space in this problem. In advantageous circumstances, UAVs may approach new cells
with high search benefits in the new search path. In this algorithm, the mutated gene is selected by
Equation (29) and the mutation result is selected based on the probability distribution in Equation (32).

(iv) Selection
Similar to the traditional selection in GA, a binary tournament selection method is used to select the
chromosomes in the population.

5.1.4. Procedures of the priority-encoded IGAFA
The procedures of the priority-encoded IGAFA, i.e., the procedures to obtain the optimal set of control input
sequences, are as shown in Table 1.

5.2. Complete search process
Basedonthe previoussections, theproceduresof a completesearchprocessformoving targetsusingCSMTPE,
are as shown in Table 2.

6. RESULTS
Simulation experiments for the multi-UAV regional cooperative search problem in this paper are performed in
Matlab. The computer configuration is as follows: Windows 10, CPU AMD(R) Ryzen(R) 7 4800HS of 2.9GHz
up to 4.2GHz, Memory 16GB of 3200MHz.

The experiment assumes a military scenario where UAVs are used to search for targets of concealed enemy
soldiers in a mission area. The UAVs search for enemies through airborne human detection equipment, while
the enemies actively evade the UAVs’ search. Set the size of the mission area as = = 4 and divide the
area into 40×40 grid cells with = 100 . Assuming that the UAV moves at a speed of 15 / and the target
moves at a maximum speed of 6 / , set the motion configuration for moving targets to be: = 40 ,
= 1, = 600 , = 0.8, 1 = 500 , and 2 = 300 , which implies = 50 and = 2. Set the