An Adaptive Bounded Hybrid A* Planner for Autonomous Mining Trucks in Confined Unstructured Mining Environments

. 2026 Sep 9;26(18):5720. doi: 10.3390/s26185720

Algorithm 1 Adaptive Bounded Hybrid A* Planner

Require: Working face map

M

, start pose

x_{s}

, target pose

x_{g}

, AMT parameters, primitive pool

U

Ensure: Final returned path

Π^{*}

1:
Initialize $OPEN$ , $CLOSED$ , $J_{best} \leftarrow + \infty$ , $Π^{*} \leftarrow Ø$
2:
Insert the start node into $OPEN$
3:
while $OPEN$ is not empty do
4:
Select $n = arg \min_{m \in OPEN} (g_{search} (m) + h (m))$
5:
Remove n from $OPEN$ and insert it into $CLOSED$
6:
Extract local descriptor set $F (x_{n})$
7:
Attempt RS analytical closure from n to $x_{g}$
8:
if the RS connection is collision-free then
9:
Compute $J_{cand} (n) = g_{true} (n) + J_{RS} (n, x_{g})$
10:
if $J_{cand} (n) < J_{best}$ then
11:
Update $J_{best} \leftarrow J_{cand} (n)$
12:
Update $Π^{*} \leftarrow Π_{cand} (n)$
13:
end if
14:
end if
15:
Compute $U_{K} (x_{n}) = TopK (U, S (\cdot | x_{n}))$
16:
Apply direction-diversity compensation to $U_{K} (x_{n})$ if necessary
17:
for each primitive $u \in U_{K} (x_{n})$ do
18:
Compute adaptive rollout length $L_{u} (x_{n})$ using (21)
19:
Roll out primitive u from node n under fixed integration step $Δ s$
20:
Generate child node $n^{'}$
21:
if $n^{'}$ is valid and collision-free then
22:
Compute $Δ g_{true} (n^{'})$
23:
Update $g_{true} (n^{'})$
24:
Compute $R_{prog} (n^{'})$ and ${\bar{R}}_{prog} (n^{'})$
25:
Compute $g_{search} (n^{'})$
26:
Insert or update $n^{'}$ in $OPEN$
27:
end if
28:
end for
29:
if $J_{best} < + \infty$ and $\min_{m \in OPEN} (g_{search} (m) + h (m)) > J_{best} + ε_{b}$ then
30:
break
31:
end if
32:
end while
33:
return $Π^{*}$