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Wang et al. Intell Robot 2023;3(4):538-64 I http://dx.doi.org/10.20517/ir.2023.30 Page 9 of 27

Basedonthedefinitionabove, theupdatedexistenceprobabilityofthetargetbasedontargetmotionprediction

in after time is denoted as − ( +1 ), which is as follows:

+1 +1
∑ ∑
− ( +1 ) = Φ ( )· ( ) (10)

= −1 = −1
After the update based on target motion prediction, the probability map will be updated again based on the
real-time detection results of airborne detection sensors of every UAV. In this paper, Bayesian criteria are used
[8]
to dynamically update the probability map . The update of existence probability after time can be classified
into the following three situations:

(i) i-th UAV finds a target in ( +1 ) with ∈ ( +1 ):

· − ( +1 )

( +1 ) = (11)

( − )· ( +1 ) +
−

(ii) i-th UAV finds nothing in ( +1 ) with ∈ ( +1 ):

(1 − )· − ( +1 )
( +1 ) = (12)

1 + ( − )· ( +1 ) −

−
(iii) is outside the area of the detection range of any UAV:

( +1 ) = − ( +1 ) (13)
3.2. Certainty map
A certainty map is a search information map that reflects the degree of UAV exploration of the mission area.
Considering that UAVs move in mission grid cells, the region division of the certainty map is the same as Ω ,

and the certainty map varies with the UAVs’ detectability and access situation. Denote the grid of a certainty
mapas Ω , inwhichthecellwithm-throwandn-thcolumnisdenotedas andthecorrespondingcertainty

is denoted as . The update of a certainty map after time can be classified into the following two situations
based on the access and the detection range of every UAV:

(i) i-th UAV flies past with the situation that has the same regional definition as ( +1 ) in Ω ( +1 ):

( +1 ) = ( ) + · [1 − ( )] (14)
As in Equation (14), the certainty of the grid cell increases with the detectability and access of UAVs.

(ii) is outside the area of the detection range of any UAV:

( +1 ) = · ( ) (15)
where ∈ (0, 1) is the attenuation coefficient of certainty.

3.3. Detection response map
A detection response map is a search information map defined in this paper to provide feedback on the target
detection results of UAVs, which solves the problem of the lack of direct search results in conventional search
information maps. The region division of the detection response map is the same as Ω , and the detection